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Sample records for acinetobacter sp bd413

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

    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.)

  2. Spread of Recombinant DNA by Roots and Pollen of Transgenic Potato Plants, Identified by Highly Specific Biomonitoring Using Natural Transformation of an Acinetobacter sp.

    de Vries, Johann; Heine, Martin; Harms, Klaus; Wackernagel, Wilfried

    2003-01-01

    Transgenic potato plants with the nptII gene coding for neomycin phosphotransferase (kanamycin resistance) as a selection marker were examined for the spread of recombinant DNA into the environment. We used the recombinant fusion of nptII with the tg4 terminator for a novel biomonitoring technique. This depended on natural transformation of Acinetobacter sp. strain BD413 cells having in their genomes a terminally truncated nptII gene (nptII′; kanamycin sensitivity) followed by the tg4 termina...

  3. Taxonomy of haemolytic and/or proteolytic strains of the genus Acinetobacter with the proposal of Acinetobacter courvalinii sp. nov. (genomic species 14 sensu Bouvet & Jeanjean), Acinetobacter dispersus sp. nov. (genomic species 17), Acinetobacter modestus sp. nov., Acinetobacter proteolyticus sp. nov. and Acinetobacter vivianii sp. nov.

    Nemec, Alexandr; Radolfova-Krizova, Lenka; Maixnerova, Martina; Vrestiakova, Eliska; Jezek, Petr; Sedo, Ondrej

    2016-04-01

    We aimed to define the taxonomic status of 40 haemolytic and/or proteolytic strains of the genus Acinetobacter which were previously classified into five putative species termed as genomic species 14BJ (n = 9), genomic species 17 (n = 9), taxon 18 (n = 7), taxon 19 (n = 6) and taxon 20 (n = 9). The strains were recovered mostly from human clinical specimens or soil and water ecosystems and were highly diverse in geographical origin and time of isolation. Comparative analysis of the rpoB and gyrB gene sequences of all strains, and the whole-genome sequences of selected strains, showed that these putative species formed five respective, well-supported clusters within a distinct clade of the genus Acinetobacter which typically, although not exclusively, encompasses strains with strong haemolytic activity. The whole-genome-based average nucleotide identity (ANIb) values supported the species status of each of these clusters. Moreover, the distinctness and coherence of the clusters were supported by whole-cell profiling based on MALDI-TOF MS. Congruent with these findings were the results of metabolic and physiological testing. We conclude that the five putative taxa represent respective novel species, for which the names Acinetobacter courvalinii sp. nov. (type strain ANC 3623T = CCUG 67960T = CIP 110480T = CCM 8635T), Acinetobacter dispersus sp. nov. (type strain ANC 4105T = CCUG 67961T = CIP 110500T = CCM 8636T), Acinetobacter modestus sp. nov. (type strain NIPH 236T = CCUG 67964T = CIP 110444T = CCM 8639T), Acinetobacter proteolyticus sp. nov. (type strain NIPH 809T = CCUG 67965T = CIP 110482T = CCM 8640T) and Acinetobacter vivianii sp. nov. (type strain NIPH 2168T = CCUG 67967T = CIP 110483T = CCM 8642T) are proposed. PMID:26822020

  4. Acinetobacter refrigeratoris [corrected] sp. nov., isolated from a domestic refrigerator.

    Feng, Guangda; Yang, Songzhen; Wang, Yonghong; Yao, Qing; Zhu, Honghui

    2014-12-01

    A Gram-negative bacterial strain, designated WB1(T), was isolated from a domestic refrigerator in Guangzhou, PR China. Cells of strain WB1(T) were oxidase-negative, catalase-positive, strictly aerobic, non-spore-forming and non-motile coccobacilli with peritrichous fimbriae-like structures. The strain was able to grow at 10-40 °C with optimum growth at 28-30 °C, pH 6.0-8.0 (optimum, pH 7.0) and 0-6 % NaCl (w/v, optimum, 0.5 %). Phylogenetic analyses based on 16S rRNA gene and rpoB gene sequences revealed that strain WB1(T) belonged to the genus Acinetobacter and was most closely related to A. indicus DSM 25388(T) (97.2 % 16S rRNA gene sequence similarity) and A. radioresistens NBRC 102413(T) (96.8 %). The DNA G + C content of strain WB1(T) was 46.74 ± 0.04 mol % and the major fatty acids comprised summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), C18:1 ω9c, C16:0 and C12:0. The predominant respiratory quinone was identified as Q-9 and the polar lipids as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and an unidentified phospholipid. Phenotypic, phylogenetic and chemotaxonomic data, including low DNA-DNA relatedness with closely related type strains, supported that strain WB1(T) represents a distinct novel species in the genus Acinetobacter, for which the name Acinetobacter refrigeratorensis sp. nov. was proposed. The type strain is WB1(T) (=GIMCC 1.663(T) = CCTCC AB 2014197(T) = KCTC 42011(T)). PMID:25103126

  5. Fatty aldehyde dehydrogenases in Acinetobacter sp. strain HO1-N: role in hexadecanol metabolism.

    Singer, M E; Finnerty, W R

    1985-01-01

    The role of fatty aldehyde dehydrogenases (FALDHs) in hexadecane and hexadecanol metabolism was studied in Acinetobacter sp. strain HO1-N. Two distinct FALDHs were demonstrated in Acinetobacter sp. strain HO1-N: a membrane-bound, NADP-dependent FALDH activity induced 5-, 15-, and 9-fold by growth on hexadecanol, dodecyl aldehyde, and hexadecane, respectively, and a constitutive, NAD-dependent, membrane-localized FALDH. The NADP-dependent FALDH exhibited apparent Km and Vmax values for decyl a...

  6. Biodegradation of pyrazosulfuron-ethyl by Acinetobacter sp. CW17.

    Wang, Yanhui; Du, Liangwei; Chen, Yingxi; Liu, Xiaoliang; Zhou, Xiaomao; Tan, Huihua; Bai, Lianyang; Zeng, Dongqiang

    2012-03-01

    The pyrazosulfuron-ethyl-degrading bacterium, designated as CW17, was isolated from contaminated soil near the warehouse of the factory producing pyrazosulfuron-ethyl in Changsha city, China. The strain CW17 was identified as Acinetobacter sp. based on analyses of 94 carbon source utilization or chemical sensitivity in Biolog microplates, conventional phenotypic characteristics, and 16S rRNA gene sequencing. When pyrazosulfuron-ethyl was provided as the sole carbon source, the effects of pyrazosulfuron-ethyl concentration, pH, and temperature on biodegradation were examined. The degradation rates of pyrazosulfuron-ethyl at initial concentrations of 5.0, 20.0, and 50.0 mg/L were 48.0%, 77.0%, and 32.6%, respectively, after inoculation for 7 days. The growth of the strain was inhibited at low pH buffers. The chemical degradation occurs much faster at low pH than at neutral and basic pH conditions. The degradation rate of pyrazosulfuron-ethyl at 30°C was faster than those at 20 and 37°C by CW17 strains. Two metabolites of degradation were analyzed by liquid chromatography-mass spectroscopy (LC/MS). Based on the identified products, strain CW17 seemed to be able to degrade pyrazosulfuron-ethyl by cleavage of the sulfonylurea bridge. PMID:22388979

  7. Reconstitution of emulsifying activity of Acinetobacter calcoaceticus BD4 emulsan by using pure polysaccharide and protein.

    N. Kaplan; Zosim, Z; Rosenberg, E

    1987-01-01

    Acinetobacter calcoaceticus BD4 and BD413 produce extracellular emulsifying agents when grown on 2% ethanol medium. For emulsifying activity, both polysaccharide and protein fractions were required, as demonstrated by selective digestion of the polysaccharide with a specific bacteriophage-borne polysaccharide depolymerase, deproteinization of the extracellular emulsifying complex with hot phenol, and reconstitution of emulsifier activity with pure polysaccharide and a polysaccharide-free prot...

  8. Fatty aldehyde dehydrogenases in Acinetobacter sp. strain HO1-N: role in hexadecane and hexadecanol metabolism

    The role of fatty aldehyde dehydrogenases (FALDHs) in hexadecane and hexadecanol metabolism was studied in Acinetobacter sp. strain HO1-N. Two distinct FALDHs were demonstrated in Acinetobacter sp. strain HO1-N: (i) a membrane-bound, NADP-dependent FALDH activity induced 5-, 15-, and 9 fold by growth on hexadecanol, dodecyl aldehyde, and hexadecane, respectively, and (ii) a constitutive, NAD-dependent, membrane-localized FALDH. Dodecyl aldehyde-negative mutants were isolated and grouped into two phenotypic classes based on growth: class 1 mutants were hexadecane and hexadecanol negative and class 2 mutants were hexadecane and hexadecanol positive. Specific activity of NADP-dependent FALDH in Ald21 (class 1 mutant) was 85% lower than that of wild-type FALDH, while the specific activity of Ald24 (class 2 mutant) was 55% greater than that of wild-type FALDH. Ald21R, a dodecyl aldehyde-positive revertant able to grow on hexadecane, hexadecanol, and dodecyl aldehyde, exhibited a 100% increase in the specific activity of the NADP-dependent FALDH. This study provides genetic and physiological evidence for the role of fatty aldehyde as an essential metabolic intermediate and NADP-dependent FALDH as a key enzyme in the dissimilation of hexadecane, hexadecanol, and dodecyl aldehyde in Acinetobacter sp. strain HO1-N

  9. Biodegradation of phenol by free and immobilized Acinetobacter sp.strain PD12

    WANG Ying; TIAN Ye; HAN Bin; ZHAO Hua-bing; BI Jian-nan; CAI Bao-li

    2007-01-01

    A new phenol-degrading bacterium with high biodegradation activity and high tolerance of phenol, strain PD 12, was isolated from the activated sludge of Tianjin Jizhuangzi Wastewater Treatment Facility in China. This strain was capable of removing 500 mg phenol/L in liquid minimal medium by 99.6% within 9 h and metabolizing phenol at concentrations up to 1100 mg/L. DNA sequencing and homologous analysis of 16S rRNA gene identified PD12 to be an Acinetobacter sp. Polyvinyl alcohol (PVA) was used as a gel matrix to immobilize Acinetobacter sp. strain PD12 by repeated freezing and thawing. The factors affecting phenol degradation of immobilized cells were investigated, and the results showed that the immobilized cells could tolerate a high phenol level and protected the bacteria against changes in temperature and pH. Storage stability and reusability tests revealed that the phenol degradation functions of immobilized cells were stable after reuse for 50 times or storing at 4℃ for 50 d. These results indicate that immobilized Acinetobacter sp. strain PD 12 possesses a good application potential in the treatment of phenol-containing wastewater.

  10. Comparative analysis of fecal microflora of healthy full-term Indian infants born with different methods of delivery (vaginal vs cesarean): Acinetobacter sp. prevalence in vaginally born infants

    Prashant Kumar Pandey; Pankaj Verma; Himanshu Kumar; Ashish Bavdekar; Milind S Patole; Yogesh S Shouche

    2012-12-01

    In this study fecal microflora of human infants born through vaginal delivery (VB) and through cesarean section (CB) were investigated using culture-independent 16S rDNA cloning and sequencing approach. The results obtained clearly revealed that fecal microbiota of VB infants distinctly differ from those in their counterpart CB infants. The intestinal microbiota of infants delivered by cesarean section appears to be more diverse, in terms of bacteria species, than the microbiota of vaginally delivered infants. The most abundant bacterial species present in VB infants were Acinetobacter sp., Bifidobacterium sp. and Staphylococcus sp. However, CB infant’s fecal microbiota was dominated with Citrobacter sp., Escherichia coli and Clostridium difficile. The intestinal microbiota of cesarean section delivered infants in this study was also characterized by an absence of Bifidobacteria species. An interesting finding of our study was recovery of large number of Acinetobacter sp. consisting of Acinetobacter pittii (former Acinetobacter genomic species 3), Acinetobacter junii and Acinetobacter baumannii in the VB infants clone library. Among these, Acinetobacter baumannii is a known nosocomial pathogen and Acinetobacter pittii (genomic species 3) is recently recognized as clinically important taxa within the Acinetobacter calcoaceticus–Acinetobacter baumannii (ACB) complex. Although none of the infants had shown any sign of clinical symptoms of disease, this observation warrants a closer look.

  11. Alcohol dehydrogenases in Acinetobacter sp. strain HO1-N: role in hexadecane and hexadecanol metabolism.

    Singer, M E; Finnerty, W R

    1985-01-01

    Multiple alcohol dehydrogenases (ADH) were demonstrated in Acinetobacter sp. strain HO1-N. ADH-A and ADH-B were distinguished on the basis of electrophoretic mobility, pyridine nucleotide cofactor requirement, and substrate specificity. ADH-A is a soluble, NAD-linked, inducible ethanol dehydrogenase (EDH) exhibiting an apparent Km for ethanol of 512 microM and a Vmax of 138 nmol/min. An ethanol-negative mutant (Eth1) was isolated which contained 6.5% of wild-type EDH activity and was deficien...

  12. Purification and some properties of carbon monoxide dehydrogenase from Acinetobacter sp. strain JC1 DSM 3803.

    Kim, K.S.; Ro, Y T; Kim, Y. M.

    1989-01-01

    A brown carbon monoxide dehydrogenase from CO-autotrophically grown cells of Acinetobacter sp. strain JC1, which is unstable outside the cells, was purified 80-fold in seven steps to better than 95% homogeneity, with a yield of 44% in the presence of the stabilizing agents iodoacetamide (1 mM) and ammonium sulfate (100 mM). The final specific activity was 474 mumol of acceptor reduced per min per mg of protein as determined by an assay based on the CO-dependent reduction of thionin. Methyl vi...

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

    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.

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

    Zuno-Floriano, Fabiola G; Miller, Marion G; Aldana-Madrid, Maria L; Hengel, Matt J; Gaikwad, Nilesh W; Tolstikov, Vladimir; Contreras-Cortés, Ana G

    2012-01-01

    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. PMID:22363586

  15. Heterotrophic nitrogen removal by Acinetobacter sp. Y1 isolated from coke plant wastewater.

    Liu, YuXiang; Hu, Tingting; Song, Yujie; Chen, Hongping; Lv, YongKang

    2015-11-01

    A strain of Acinetobacter sp. Y1, which exhibited an amazing ability to remove ammonium, nitrite and nitrate, was isolated from the activated sludge of a coking wastewater treatment plant. The aim of this work was to study the ability, influence factors and possible pathway of nitrogen removal by Acinetobacter sp. Y1. Results showed that maximum removal rate of NH4(+)-N by the strain was 10.28 mg-N/L/h. Carbon source had significant influence on the growth and ammonium removal efficiencies of strain Y1. Pyruvate, citrate and acetate were favourable carbon sources for the strain. Temperature, pH value and shaking speed could affect the growth and nitrogen removal ability. Nitrate or nitrite could be used as a sole nitrogen source for the growth and removed efficiently by the strain. N2 levels increased to 53.74%, 50.21% and 55.13% within 36 h when 100 mg/L NH4(+)-N, NO2(-)-N or NO3(-) -N was used as sole nitrogen source in the gas detection experiment. The activities of hydroxylamine oxidoreductase (HAO), nitrate reductase (NR) and nitrite reductase (NiR), which are key enzymes in heterotrophic nitrification and aerobic denitrification, were all detectable in the strain. Consequently, a possible pathway for ammonium removal by the strain was also suggested. PMID:25910961

  16. Genome sequence of Acinetobacter sp. strain HA, isolated from the gut of the polyphagous insect pest Helicoverpa armigera.

    Malhotra, Jaya; Dua, Ankita; Saxena, Anjali; Sangwan, Naseer; Mukherjee, Udita; Pandey, Neeti; Rajagopal, Raman; Khurana, Paramjit; Khurana, Jitendra P; Lal, Rup

    2012-09-01

    In this study, Acinetobacter sp. strain HA was isolated from the midgut of a fifth-instar larva of Helicoverpa armigera. Here, we report the draft genome sequence (3,125,085 bp) of this strain that consists of 102 contigs, 2,911 predicted coding sequences, and a G+C content of 41%. PMID:22933775

  17. Molecular characterization of clinical multiresistant isolates of Acinetobacter sp. from hospitals in Porto Alegre, State of Rio Grande do Sul, Brazil

    Alessandra Einsfeld Ferreira

    2011-12-01

    Full Text Available INTRODUCTION: Hospitals around the world have presented multiresistant Acinetobacter sp. outbreaks. The spread of these isolates that harbor an increasing variety of resistance genes makes the treatment of these infections and their control within the hospital environment more difficult. This study aimed to evaluate the occurrence and dissemination of Acinetobacter sp. multiresistant isolates and to identify acquired resistance genes. METHODS: We analyzed 274 clinical isolates of Acinetobacter sp. from five hospitals in Porto Alegre, RS, Brazil. We evaluated the susceptibility to antimicrobial, acquired resistance genes from Ambler's classes B and D, and performed molecular typing of the isolates using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR technique. RESULTS: A high (68% percentage of multiresistant isolates of Acinetobacter sp. was observed, and 69% were resistant to carbapenems. We identified 84% of isolates belonging to species A. baumannii because they presented the gene blaOXA-51. The gene blaOXA-23 was detected in 62% of the isolates, and among these, 98% were resistant to carbapenems. Using the ERIC-PCR technique, we identified clones of Acinetobacter sp. spread among the four hospitals analyzed during the sampling period. CONCLUSIONS: The data indicate the dissemination of Acinetobacter sp. isolates among hospitals and their permanence in the hospital after one year.

  18. Identification of Novel Genes Involved in Long-Chain n-Alkane Degradation by Acinetobacter sp. Strain DSM 17874▿

    Throne-Holst, Mimmi; Wentzel, Alexander; Ellingsen, Trond E.; Kotlar, Hans-Kristian; Zotchev, Sergey B.

    2007-01-01

    Acinetobacter sp. strain DSM 17874 is capable of utilizing n-alkanes with chain lengths ranging from that of decane (C10H22) to that of tetracontane (C40H82) as a sole carbon source. Two genes encoding AlkB-type alkane hydroxylase homologues, designated alkMa and alkMb, have been shown to be involved in the degradation of n-alkanes with chain lengths of from 10 to 20 C atoms in this strain. Here, we describe a novel high-throughput screening method and the screening of a transposon mutant library to identify genes involved in the degradation of n-alkanes with C chain lengths longer than 20, which are solid at 30°C, the optimal growth temperature for Acinetobacter sp. strain DSM 17874. A library consisting of approximately 6,800 Acinetobacter sp. strain DSM 17874 transposon mutants was constructed and screened for mutants unable to grow on dotriacontane (C32H66) while simultaneously showing wild-type growth characteristics on shorter-chain n-alkanes. For 23 such mutants isolated, the genes inactivated by transposon insertion were identified. Targeted inactivation and complementation studies of one of these genes, designated almA and encoding a putative flavin-binding monooxygenase, confirmed its involvement in the strain's metabolism of long-chain n-alkanes. To our knowledge, almA represents the first cloned gene shown to be involved in the bacterial degradation of long-chain n-alkanes of 32 C's and longer. Genes encoding AlmA homologues were also identified in other long-chain n-alkane-degrading Acinetobacter strains. PMID:17400787

  19. Alcohol dehydrogenases in Acinetobacter sp. strain HO1-N: role in hexadecanse and hexadecanol metabolism

    Multiple alcohol dehydrogenases (ADH) were demonstrated in Acinetobacter sp. strain HO1-N. ADH-A and ADH-B were distinguished on the basis of electrophoretic mobility, pyridine nucleotide cofactor requirement, and substrate specificity. ADH-A is a soluble, NAD-linked, inducible ethanol dehydrogenase (EDH). An ethanol-negative mutant (Eth1) was isolated which contained 6.5% of wild-type EDH activity and was deficient in ADH-A. Eth1 exhibited normal growth on hexadecane and hexadecanol. A second ethanol-negative mutant (Eth3) was acetaldehyde dehydrogenase (ALDH) deficient, having 12.5% of wild-type ALDH activity. Eth3 had threefold-higher EDH activity than the wild-type strain. ALDH is a soluble, NAD-linked, ethanol-inducible enzyme. Eth3 exhibited normal growth on hexadecane, hexadecanol, and fatty aldehyde. ADH-B is soluble, constitutive, NADP-linked ADH which was active with medium-chain-length alcohols. Hexadecanol dehydrogenase (HDH), a soluble and membrane-bound, NAD-linked ADH, was induced 5- to 11-fold by growth on hexadecane or hexadecanol. HDH was distinct from ADH-A and ADH-B. NAD-linked HDH appears to possess a functional role in hexadecane and hexadecanol dissimilation

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

    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.

  1. NCBI nr-aa BLAST: CBRC-MDOM-08-0245 [SEVENS

    Full Text Available CBRC-MDOM-08-0245 ref|YP_045158.1| putative fimbrial usher protein [Acinetobacter s...p. ADP1] gb|AAS90700.1| AcuC [Acinetobacter sp. BD413] emb|CAG67336.1| protein AcuC; putative fimbrial usher protein [Acinetobacter sp. ADP1] YP_045158.1 0.47 32% ...

  2. A metallo-keratinase from a newly isolated Acinetobacter sp. R-1 with low collagenase activity and its biotechnological application potential in leather industry.

    Zhang, Rong-Xian; Gong, Jin-Song; Zhang, Dan-Dan; Su, Chang; Hou, Ying-Shuo; Li, Heng; Shi, Jin-Song; Xu, Zheng-Hong

    2016-01-01

    Microbial keratinase is a well-recognized enzyme that can specifically degrade insoluble keratins. A keratinase-producing bacterium was isolated from a duck ranch soil and identified as Acinetobacter sp. R-1 based on the biochemical characteristics and 16S rDNA gene sequencing. It showed high keratinase activity and low collagenase activity. The keratinase was purified to electrophoretic homogeneity with 6.69% recovery, 2.68-fold purification and an estimated molecular weight of 25 kDa. Additionally, the keratinase showed optimal activity at 50 °C and pH11. Keratinase activity of Acinetobacter sp. significantly increased in the presence of Li(+), Na(+), and Ca(2+), while it was completely inhibited by EDTA, indicating it was a metallo-keratinase. Moreover, the crude keratinase from Acinetobacter sp. R-1 could thoroughly depilate goat skin and simultaneously modify the wool surface, which indicated its applicable potential in leather and textile industries. PMID:26589609

  3. Algicidal and denitrification characterization of Acinetobacter sp. J25 against Microcystis aeruginosa and microbial community in eutrophic landscape water.

    Su, Jun Feng; Ma, Min; Wei, Li; Ma, Fang; Lu, Jin Suo; Shao, Si Cheng

    2016-06-15

    Acinetobacter sp. J25 exhibited good denitrification and high algicidal activity against toxic Microcystis aeruginosa. Response surface methodology (RSM) experiments showed that the maximum algicidal ratio occurred under the following conditions: temperature, 30.46°C; M. aeruginosa density, 960,000cellsmL(-1); and inoculum, 23.75% (v/v). Of these, inoculum produced the maximum effect. In the eutrophic landscape water experiment, 10% bacterial culture was infected with M. aeruginosa cells in the landscape water. After 24days, the removal ratios of nitrate and chlorophyll-a were high, 100% and 87.86%, respectively. The denitrification rate was approximately 0.118mgNO3(-)-N·L(-1)·h(-1). Moreover, the high-throughput sequencing result showed that Acinetobacter sp. J25 was obviously beneficial for chlorophyll-a and nitrate removal performance in the eutrophic landscape water treatment. Therefore, strain J25 is promising for the simultaneous removal of chlorophyll-a and nitrate in the eutrophic landscape water treatment. PMID:27126181

  4. [Susceptibility to antibiotics and biochemical activity of strains of Acinetobacter sp. isolated from various sources].

    Gospodarek, E

    1993-01-01

    The study was performed on 576 Acinetobacter strains isolated from clinical material, objects from hospital, environment, soil, water and from animals. Applying API 20NE system identification was following: A. baumanii (61.1%), A. junii (19.4%), A. haemolyticus (4.3%), A. lwoffii (3.3%), A. johnsonii (0.52%) and not belonging to above genus strains (11.3%). Over 47% strains of Acinetobacter were isolated from clinical material as the only bacteria (mainly from samples received from intensive care units and surgical and urological wards). Out of 23 antibiotics and antimicrobials used for investigation of 535 strains of Acinetobacter, most active were imipenem (99%) of susceptible strains, ofloxacin and ciprofloxacin (95%) and netilmicin (88%). Multiple resistant strains were isolated more frequently from hospital environment than from other sources--these were mostly A. baumanii and A. junii. PMID:8189806

  5. LOGICAL AND EXPERIMENTAL DESIGN FOR PHENOL DEGRADATION USING IMMOBILIZED ACINETOBACTER SP. CULTURE

    Amro Abd Al Fattah Amara

    2010-05-01

    Full Text Available Phenol degradation processes were conducted through a series of enzymatic reactions effects and is affect by different components of the microbial metabolic flux. Using different optimization strategies like mutagenesis could lead to a successful optimization but also lead to lost of some important microbial features or to release a new virulence or unexpected characters. Plackett-Burman closes much gab between optimization, safety, time, cost, Man/hr, the complexity of the metabolic flux etc. Using Plackett-Burman experimental design lead to map the points affect in the optimization process by well understanding their request from nutrient and the best environmental condition required. In this study nine variables include pH (X1, oC (X2, glucose (X3, yeast extract (X4, meat extract (X5, NH4NO3 (X6, K-salt (X7, Mg-salt (X8 and trace element (X9 are optimized during phenol degradation by Acinetobacter sp., using Plackett-Burman design method. Plackett-Burman included 16 experiments, each was used in two levels, [-1] low and high [+1]. According to Blackett-Burman design experiments the maximum degradation rate was 31.25 mg/l/h. Logical and statistical analysis of the data lead to select pH, Temperature and Meat extract as three factors affecting on phenol degradation rate. These three variables have been used in Box-Behnken experimental design for further optimization. Meat extract, which is not statistically recommended for optimization has been used while it can substitute trace element, which is statistically significant. Glucose, which is statistically significant, did not included while it has a negative effect and gave the best result at 0 g/l amount. Glucose has been completely omitted from the media.  pH, temperature and meat extract were used in fifteen experiments each was used in three levels, –1, 0, and +1 according to Box-Behnken design. Microsoft Excel 2002 solver tool was used to optimize the model created from Box-Behnken. The

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

    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.

  7. Biodegradation of crude oil surfactant production by strain Acinetobacter sp. D3-2 isolated from oil-contaminated soil

    Bao, Mutai; Wang, Lina; Li, Yiming [Ocean University of China (China)], email: mtbao@ouc.edu.cn; Cao, Lixin; Sun, Peiyan [North China Sea Environmental Monitoring Center of State Oceanic Administration (China)

    2011-07-01

    The increasing needs for energy world-wide have led to the offshore petroleum operations and this raises concerns about hydrocarbon contamination of the marine environment. There is consequently a need to find solutions for removing hydrocarbons from marine environments and the aim of this paper is to study the capacity of bacterium D3-2 to degrade crude oil. The bacterium was extracted from oil contaminated soil samples and was identified as Acinetobacter sp. D3-2. The optimum conditions for the growth of this bacterium and its production of biosurfactant were determined and an Erlenmeyer flash experiment was conducted to determine the biosurfactant's capacity to degrade hydrocarbon. Results showed that the optimum conditions for the bacterium's growth are pH 8.0, 30 degrees Celsius and 3% NaCl concentration; it was found that acinetobacter can degrade 82% hydrocarbons under these conditions. This study demonstrated that bioremediation of hydrocarbons is possible.

  8. 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

    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.

  9. Intensification of microbial exopolysaccharide ethapolan synthesis under Acinetobacter sp. IМV B-7005 cultivation on sunflower oil

    M. Ivahniuk

    2015-05-01

    Full Text Available Introduction.Microbial exopolysaccharides (EPS by the ability of their solutions to change the rheological properties of aqueous systems are widely used in various industries. In recent years, research on the use of industrial waste (including oil-containing to obtain practically valuable microbial metabolites intensified. Materials and methods.Cultivation of Acinetobactersp. IМV B-7005 strain was performed in liquid medium, containing as a carbon source sunflower oil (1−5 %, v/v, a source of nitrogen – ammonium nitrate (0.4−0.8 g/l, a source of pantothenate − multivitamin complex «Complevit» (0.00085 and0.00095 %. EPSconcentration was determined gravimetrically after precipitation with isopropanol, EPS-synthesizing ability − as a ratio of EPS concentration to biomass concentration, wich was expressed as g EPS / g biomass. Results and discussions. It was established that increasing the concentration of sunflower oil in basic medium for Acinetobacter sp. IMV B -7005 cultivation to 4−5% was accompanied by decrease of ethapolan synthesis compared with those in the medium containing lower (2−3 % substrate concentration. Increasing ammonium nitrate content to 0.6 g/l and/or pantothenate concentration to 0.00095% in a medium with 5% sunflower oil allowed to increase the amount of ethapolan synthesized up to 6.6−6.7 g/l, that is in 1.3−1.4 times higher than in the basic medium with the same concentration of the substrate but lower NH4NO3 (0.4 g/l and pantothenate (0.00085 %. Conclusion. The obtained results indicate the possibility of microbial polysaccharide ethapolan synthesis under Acinetobacter sp. ІMV B -7005 cultivation in the medium with a high content of sunflower oil. These data are the basis for the development of ethapolan technology using as a substrate fried oil.

  10. Purification and Characterization of Catechol 1,2-Dioxygenase from Acinetobacter sp. Y64 Strain and Escherichia coli Transformants.

    Lin, J; Milase, R N

    2015-12-01

    This study intends to purify and characterize catechol 1,2-dioxygenase (C1,2O) of phenol-degrading Acinetobacter sp. Y64 and of E. coli transformant. Acinetobacter sp. Y64 was capable of degrading 1000 mg/L of phenol within 14 ± 2 h at 30 °C, 160 rpm and pH of 7. One C1,2O of 36 kDa was purified using ammonium sulphate precipitation and Hitrap QFF column chromatograph with 49% recovery and a 10.6-fold increase in purity. Purified Y64 C1,2O had temperature and pH optimum at 37 °C and pH 7.7 respectively with the Michaelis constant of 17.53 µM and the maximal velocity of 1.95 U/mg, respectively. The presence of Fe(3+) or Fe(2+) enhanced the activity of Y64 C1,2O while other compounds such as Ca(2+), and EDTA had an inhibitory effect. 80% of C1,2O activity remained using 4-nitrocatechol as substrate while 2% remained using 3-methylcatechol compared with that using catechol. Y64 catA gene encoding C1,2O was amplified using PCR cloned into pET22b vector and expressed in Escherichia coli BL21 DE3 (pLysS) after transformation. Purified and cloned Y64 C1,2O show no significant differences in the biochemical properties. The phylogenetic tree based on the protein sequences indicates that these C1,2Os possess a common ancestry. PMID:26563518

  11. Ocorrência e perfil de sensibilidade a antimicrobianos em Pseudomonas aeruginosa e Acinetobacter sp. em um hospital terciário, no sul do Brasil Occurrence and the susceptibility to antimicrobial agents in Pseudomonas aeruginosa and Acinetobacter sp. at a tertiary hospital in southern Brazil

    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.INTRODUCTION: The main mechanism of emerging resistance in Pseudomonas aeruginosa and Acinetobacter sp. isolates is the production of metallo-β-lactamases (MβLs. MβLs are enzymes capable of hydrolyzing cephalosporins, penicillins and carbapenems, but not monobactams (aztreonam, which are often used as antimicrobial therapy to treat nosocomial infections. METHODS: An observational descriptive and retrospective study was designed to assess the frequency of MβLs among strains of P. aeruginosa and Acinetobacter sp. obtained from a tertiary hospital in southern Brazil. RESULTS: MβL production was observed in 77.6% (n = 173/223 for P. aeruginosa isolates and 22.4% (n = 50/223 of

  12. Monolayer Adsorption of a “Bald” Mutant of the Highly Adhesive and Hydrophobic Bacterium Acinetobacter sp. Strain Tol 5 to a Hydrocarbon Surface▿

    Hori, Katsutoshi; Watanabe, Hisami; Ishii, Shun'ichi; Tanji, Yasunori; Unno, Hajime

    2008-01-01

    The affinity of microbial cells for hydrophobic interfaces is important because it directly affects the efficiency of various bioprocesses, including green biotechnologies. The toluene-degrading bacterium Acinetobacter sp. strain Tol 5 has filamentous appendages and a hydrophobic cell surface, shows high adhesiveness to solid surfaces, and self-agglutinates. A “bald” mutant of this bacterium, strain T1, lacks the filamentous appendages and has decreased adhesiveness but retains a hydrophobic ...

  13. Production of a Solvent, Detergent, and Thermotolerant Lipase by a Newly Isolated Acinetobacter sp. in Submerged and Solid-State Fermentations

    Anahita Khoramnia; Afshin Ebrahimpour; Boon Kee Beh; Oi Ming Lai

    2011-01-01

    The lipase production ability of a newly isolated Acinetobacter sp. in submerged (SmF) and solid-state (SSF) fermentations was evaluated. The results demonstrated this strain as one of the rare bacterium, which is able to grow and produce lipase in SSF even more than SmF. Coconut oil cake as a cheap agroindustrial residue was employed as the solid substrate. The lipase production was optimized in both media using artificial neural network. Multilayer normal and full feed forward backpropagati...

  14. Kinetic analysis of simultaneous denitrification and biomineralization of novel Acinetobacter sp. CN86.

    Su, Jun-Feng; Shi, Jing-Xin; Huang, Ting-Lin; Ma, Fang

    2016-08-15

    A novel aerobic denitrification and biomineralization strain CN86 was isolated from the Qu Jiang artificial lake. Based on phylogenetic characteristics, the isolated strain was identified as Acinetobacter species. Strain CN86 was confirmed to have the ability to perform simultaneous denitrification and biomineralization. Exponential decay equation was used for the matching of kinetic processes on denitrification and biomineralization. A highest nitrate removal rate was achieved at the pH7.0, organic concentration of 1.5g/L and temperature of 30°C. An optimal hardness removal rate was obtained at the pH9.0, organic concentration of 2.0g/L and temperature of 30°C. Strain CN86 is a suitable candidate for the simultaneous removal of nitrate and hardness in groundwater treatment. PMID:27287863

  15. Survey of Phenantherene Biodegradation's Model inContaminated Soils by Acinetobacter SP

    M Farzadkia

    2009-11-01

    Full Text Available Backgrounds and Objectives: Polycyclic aromatic hydrocarbons (PAHs are a group of hazardous pollutants which have carcinogenic and mutagenic properties and accumulated in environment by different actions, therefore treatment of them is important. Biological treatments are simple and cheep technologies. This technology was recommended as a cost- effective method for treatment of these pollutants. In order to investigate the trend of pollution reduction of petroleum hydrocarbons in bioremediation, the phenanthrene biodegradation's model in contaminated soils was studied."nMaterials and Methods: Firstly, PAHs capable degrading bacteria was isolated from petroleum contaminated soils and then their ability for biodegradation of phenanthrene was assessed in slurry phase. After that by using Acinetobacter which have the most potential of removing phenanthrene from soil, the biodegradation model was investigated in bench scale."nResults: Phenantherene removal efficiency was obtained 99.4% for 100 mg/kg and 96 % for 500 mg/kg concentrations in 33 and 60 days biodegradation period respectively. Phenantherene reduction rate varied from 2.99 to 8.86 and 1.4 to 11.09 mg/kg/day for 100 and 500 mg/kg concentrations, respectively."nConclusion: Rate of phenantherene removal is depended on primary concentration of contamination and by increasing of primary concentration, phenantherene removal rate was increased. Also removal efficiency followed zero and first order kinetic model with good correlation.

  16. Reaction engineering studies on the biodegradation of anthracene on bioremediation of diesel contaminated soil using Acinetobacter sp. (ATCC no. 14293)

    Roy, R.; Bhattacharya, P.; Chowdhury, R. [Jadavpur Univ., Kolkata, West Bengal (India). Dept. of Chemical Engineering

    2006-08-15

    Bioremediation is a simple and cost-effective means of cleaning up chemically contaminated soil. This study was conducted to better understand the complex reaction chemistry associated with the biodegradation of anthracene. Anthracene was selected as a model PAH because it represents a typical polyaromatic hydrocarbon found in diesel. This paper presented the results of a systematic bioprocess study of the monoculture system that can decompose anthracene from its simulated mixture in methanol using a pure bacterial strain, Acinetobacter sp. (ATCC no. 14293). In a separate attempt, bioremediation of diesel contaminated soil to reduce total aromatic content using the same bacterial strain was carried out. The kinetic parameters needed for bioreactor design were also evaluated. It was observed that Monod's classical substrate uninhibited model can predict cell growth rate and substrate depletion kinetics. When coupled with first order cell decay rate, it can also be used to express the reaction engineering behaviour of the bioremediation of diesel contaminated soil. It was shown that the maximum specific cell growth rate in soil depends on moisture content of the oil-contaminated soil. 20 refs., 1 tab., 7 figs.

  17. AtaA, a new member of the trimeric autotransporter adhesins from Acinetobacter sp. Tol 5 mediating high adhesiveness to various abiotic surfaces.

    Masahito Ishikawa

    Full Text Available Acinetobacter sp. Tol 5 exhibits an autoagglutinating nature and noteworthy adhesiveness to various abiotic surfaces from hydrophobic plastics to hydrophilic glass and stainless steel. Although previous studies have suggested that bacterionanofibers on Tol 5 cells are involved in the adhesive phenotype of Tol 5, the fiber that directly mediates Tol 5 adhesion has remained unknown. Here, we present a new member of trimeric autotransporter adhesins designated AtaA, which we discovered by analyzing a less adhesive mutant of Tol 5, T1, obtained by transposon mutagenesis. AtaA forms thinner and shorter nanofibers than fimbriae on Tol 5 cells. We performed target disruption of ataA by allelic marker exchange, and the resulting ΔataA strain was complemented with ataA on the Escherichia coli-Acinetobacter shuttle vector, which was newly constructed. These results proved that AtaA is essential for Tol 5's autoagglutinating nature and high adhesiveness to surfaces of various materials. In addition, the adhesiveness to solid surfaces mediated by AtaA is notably higher than that mediated by YadA of Yersinia enterocolitica WA-314. Moreover, and importantly, these characteristics can be conferred to the non-adhesive, non-agglutinating bacterium Acinetobacter sp. ADP1 in trans by transformation with ataA, with expected applications to microbial immobilization.

  18. Isolation and Denitrification Mechanism of an Aerobic Heterotrophic Bacterium Acinetobacter sp. YY-5%好氧异养硝化菌Acinetobacter sp.YY-5的分离鉴定及脱氮机理

    金敏; 王景峰; 孔庆鑫; 赵祖国; 王新为; 谌志强; 陈照立; 邱志刚; 李君文

    2009-01-01

    通过异养硝化培养基获得一株高效脱氮细菌,并通过形态学特征、生理生化反应及16S rDNA同源性比较对筛得菌株进行了鉴定;分别以NO_3~--N和NO_2~--N为唯一氮源,通过对脱氮过程中各种含氮代谢物的定量及对脱氮相关基因氨单加氧酶基因(amoA)、羟胺氧化酶基因(hao)、周质硝酸盐还原酶亚基基因(napA)的扩增及测序比较,对该菌株的生理途径及脱氮机理进行了研究.结果表明,高效脱氮细菌YY-5不能发生好氧反硝化,但能在3 d内将氨氮由95.23 mg/L降解至1.29 mg/L,降解率达妻98.6%,同时未发现亚硝酸盐氮、硝酸盐氮积累;对该菌主要代谢气体产物进行检测,发现CO_2和N_2明显增多,无N_2O生成;经鉴定,初步判定该菌为不动杆菌属,命名为Acinetobacter sp.YY-5;从该菌基因组中均能扩增出amoA、hao、napA等基因,其中napA与hao基因与已报道的napA与hao基因进行Blaster较,发现具有较大差别.图6表3参15%An aerobic heterotrophic bacterium YY-5, which could degrade NH_4~(+)-N from 95.23 mg/L to 1.29 mg/L in 3 days, was studied to reveal its denitrification methanism at the level of product characteristics and several denitrification enzymes encoding genes. The results demonstrated the bacteria produced large quantities of CO_2 and N_2, but small nitrite and nitrate accumulations. Furthermore, strain YY-5 had ammonia monooxygenase encoding gene (amoA) which encodes the enzyme to oxidize ammonia to hydroxylamine. Also, the strain had a new hydroxylamine oxidoreductase encoding gene (hao) whose sequence was distinct not only to that of autotrophic bacteria but also to that of heterotrophie bacteria. Its napA gene was also great different with the reported genes from the known aerobic heterotrophic bacteria by Blast comparison. The strain was identified as Acinetobacter sp. YY-5 according to its morphological, physiological and biochemical characters, as well as 16S rDNA sequence homology

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

    Gururaj, P; Ramalingam, Subramanian; Nandhini Devi, Ganesan; Gautam, Pennathur

    2016-01-01

    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 14.5U/mL was observed at 30°C and pH 7, using a 0.5% (v/v) inoculum, 2% (v/v) castor oil (inducer), and agitation 150rpm. The optimized conditions from the shake flask experiments were validated in a 3L lab scale bioreactor, and the lipase production increased to 48U/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 45kDa 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°C 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 16.98U/mg, 0.51mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate. PMID:27268114

  20. Ocorrência e perfil de sensibilidade a antimicrobianos em Pseudomonas aeruginosa e Acinetobacter sp. em um hospital terciário, no sul do Brasil

    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.

  1. Complete genome sequence of Acinetobacter sp. TTH0-4, a cold-active crude oil degrading strain isolated from Qinghai-Tibet Plateau.

    Zhang, Gaosen; Chen, Tuo; Chang, Sijing; Zhang, Wei; Wu, Xiukun; Wu, Minghui; Wang, Yilin; Long, Haozhi; Chen, Ximing; Wang, Yun; Liu, Guangxiu

    2016-05-20

    Acinetobacter sp. strain TTH0-4 was isolated from a permafrost region in Qinghai-Tibet Plateau. With its capability to degrade crude oil at low temperature, 10°C, the strain could be an excellent candidate for the bioremediation of crude oil pollution in cold areas or at cold seasons. We sequenced and annotated the whole genome to serve as a basis for further elucidation of the genetic background of this promising strain, and provide opportunities for investigating the metabolic and regulatory mechanisms and optimizing the biodegradative activity in cold environment. PMID:26988394

  2. Ocorrência e perfil de sensibilidade a antimicrobianos em Pseudomonas aeruginosa e Acinetobacter sp. em um hospital terciário, no sul do Brasil

    Gabriele Mariani Machado; Aldalise Lago; Sérgio Roberto Riccardi Fuentefria; Daiane Bopp Fuentefria

    2011-01-01

    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 retros...

  3. Ocorrência e perfil de sensibilidade a antimicrobianos em Pseudomonas aeruginosa e Acinetobacter sp. em um hospital terciário, no sul do Brasil Occurrence and the susceptibility to antimicrobial agents in Pseudomonas aeruginosa and Acinetobacter sp. at a tertiary hospital in southern Brazil

    Gabriele Mariani Machado; Aldalise Lago; Sérgio Roberto Riccardi Fuentefria; Daiane Bopp Fuentefria

    2011-01-01

    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, desc...

  4. Draft Genome Sequence of Acinetobacter sp. Strain BMW17, a Cellulolytic and Plant Growth-Promoting Bacterium Isolated from the Rhizospheric Region of Phragmites karka of Chilika Lake, India.

    Mishra, Samir R; Ray, Lopamudra; Panda, Ananta Narayan; Sahu, Neha; Xess, Sonal S; Jadhao, Sudhir; Suar, Mrutyunjay; Adhya, Tapan Kumar; Rastogi, Gurdeep; Pattnaik, Ajit Kumar; Raina, Vishakha

    2016-01-01

    We report the 3.16 Mb draft genome of Acinetobacter sp. strain BMW17, a Gram-negative bacterium in the class of Gammaproteobacteria, isolated from the rhizospheric region of Phragmites karka, an invasive weed in Chilika Lake, Odisha, India. The strain BMW17(T) is capable of degrading cellulose and is also an efficient plant growth promoter that can be useful for various phytoremedial and commercial applications. PMID:27365343

  5. Draft Genome Sequence of Acinetobacter sp. Strain BMW17, a Cellulolytic and Plant Growth-Promoting Bacterium Isolated from the Rhizospheric Region of Phragmites karka of Chilika Lake, India

    Mishra, Samir R.; Ray, Lopamudra; Panda, Ananta Narayan; Sahu, Neha; Xess, Sonal S.; Jadhao, Sudhir; Suar, Mrutyunjay; Adhya, Tapan Kumar; Rastogi, Gurdeep; Pattnaik, Ajit Kumar

    2016-01-01

    We report the 3.16 Mb draft genome of Acinetobacter sp. strain BMW17, a Gram-negative bacterium in the class of Gammaproteobacteria, isolated from the rhizospheric region of Phragmites karka, an invasive weed in Chilika Lake, Odisha, India. The strain BMW17T is capable of degrading cellulose and is also an efficient plant growth promoter that can be useful for various phytoremedial and commercial applications. PMID:27365343

  6. Lack of detectable DNA uptake by bacterial gut isolates grown in vitro and by Acinetobacter baylyi colonizing rodents in vivo.

    Nordgård, Lise; Nguyen, Thuy; Midtvedt, Tore; Benno, Yoshimi; Traavik, Terje; Nielsen, Kaare M

    2007-01-01

    Biological risk assessment of food containing recombinant DNA has exposed knowledge gaps related to the general fate of DNA in the gastrointestinal tract (GIT). Here, a series of experiments is presented that were designed to determine if genetic transformation of the naturally competent bacterium Acinetobacter baylyi BD413 occurs in the GIT of mice and rats, with feed-introduced bacterial DNA containing a kanamycin resistance gene (nptII). Strain BD413 was found in various gut locations in germ-free mice at 10(3)-10(5) CFU per gram GIT content 24-48 h after administration. However, subsequent DNA exposure of the colonized mice did not result in detectable bacterial transformants, with a detection limit of 1 transformant per 10(3)-10(5) bacteria. Further attempts to increase the likelihood of detection by introducing weak positive selection with kanamycin of putative transformants arising in vivo during a 4-week-long feeding experiment (where the mice received DNA and the recipient cells regularly) did not yield transformants either. Moreover, the in vitro exposure of actively growing A. baylyi cells to gut contents from the stomach, small intestine, cecum or colon contents of rats (with a normal microbiota) fed either purified DNA (50 microg) or bacterial cell lysates did not produce bacterial transformants. The presence of gut content of germfree mice was also highly inhibitory to transformation of A. baylyi, indicating that microbially-produced nucleases are not responsible for the sharp 500- to 1,000,000-fold reduction of transformation frequencies seen. Finally, a range of isolates from the genera Enterococcus, Streptococcus and Bifidobacterium spp. was examined for competence expression in vitro, without yielding any transformants. In conclusion, model choice and methodological constraints severely limit the sample size and, hence, transfer frequencies that can be measured experimentally in the GIT. Our observations suggest the contents of the GIT shield or

  7. Production of a solvent, detergent, and thermotolerant lipase by a newly isolated Acinetobacter sp. in submerged and solid-state fermentations.

    Khoramnia, Anahita; Ebrahimpour, Afshin; Beh, Boon Kee; Lai, Oi Ming

    2011-01-01

    The lipase production ability of a newly isolated Acinetobacter sp. in submerged (SmF) and solid-state (SSF) fermentations was evaluated. The results demonstrated this strain as one of the rare bacterium, which is able to grow and produce lipase in SSF even more than SmF. Coconut oil cake as a cheap agroindustrial residue was employed as the solid substrate. The lipase production was optimized in both media using artificial neural network. Multilayer normal and full feed forward backpropagation networks were selected to build predictive models to optimize the culture parameters for lipase production in SmF and SSF systems, respectively. The produced models for both systems showed high predictive accuracy where the obtained conditions were close together. The produced enzyme was characterized as a thermotolerant lipase, although the organism was mesophile. The optimum temperature for the enzyme activity was 45°C where 63% of its activity remained at 70°C after 2 h. This lipase remained active after 24 h in a broad range of pH (6-11). The lipase demonstrated strong solvent and detergent tolerance potentials. Therefore, this inexpensive lipase production for such a potent and industrially valuable lipase is promising and of considerable commercial interest for biotechnological applications. PMID:21960739

  8. Production of a Solvent, Detergent, and Thermotolerant Lipase by a Newly Isolated Acinetobacter sp. in Submerged and Solid-State Fermentations

    Anahita Khoramnia

    2011-01-01

    Full Text Available The lipase production ability of a newly isolated Acinetobacter sp. in submerged (SmF and solid-state (SSF fermentations was evaluated. The results demonstrated this strain as one of the rare bacterium, which is able to grow and produce lipase in SSF even more than SmF. Coconut oil cake as a cheap agroindustrial residue was employed as the solid substrate. The lipase production was optimized in both media using artificial neural network. Multilayer normal and full feed forward backpropagation networks were selected to build predictive models to optimize the culture parameters for lipase production in SmF and SSF systems, respectively. The produced models for both systems showed high predictive accuracy where the obtained conditions were close together. The produced enzyme was characterized as a thermotolerant lipase, although the organism was mesophile. The optimum temperature for the enzyme activity was 45°C where 63% of its activity remained at 70°C after 2 h. This lipase remained active after 24 h in a broad range of pH (6–11. The lipase demonstrated strong solvent and detergent tolerance potentials. Therefore, this inexpensive lipase production for such a potent and industrially valuable lipase is promising and of considerable commercial interest for biotechnological applications.

  9. Acinetobacter johnsonii and Acinetobacter lwoffii - the emerging fish pathogens

    Kozińska Alicja

    2014-06-01

    Full Text Available The aim of this study was to characterise Acinetobacter sp. isolated from fish. Eight isolates obtained from diseased rainbow trout and common carp cultured in Poland were analysed. The isolates were identified using API 20 NE system as Acinetobacter sp. Afterwards, they were identified by sequencing 16S rDNA gene fragment. The bacteria were identified as A. johnsonii (two isolates, A. lwoffii (two isolates, A. junii/johnsonii (one isolate, A. calcoaceticus (one isolate, and Acinetobacter sp. (two isolates. The drug resistance of isolates was examined. The majority of the isolates were resistant to ampicilin, amoxicillin, and cephalothin and all demonstrated sensitivity to fluoroquinolones, except of one isolate. Two isolates were selected for the experimental infection of trout and carp to confirm their pathogenicity. Experimentally infected fish showed disease symptoms similar to those observed in fish naturally infected with these bacteria. This is the first report concerning pathogenicity of A. johnsonii for rainbow trout and A. lwoffii for common carp. These bacteria were regarded as emerging opportunistic pathogens of fish farmed in Poland. Acinetobacter strains are commonly known as microorganisms transmitting the antibiotic resistance genes. Therefore, they might have a great impact on the resistance transfer in aquaculture.

  10. Biofilm formation and biocide resistance of acinetobacter baumannii

    Shoukat, Kamran

    2014-01-01

    Multi drug resistant (MDR) strains of Acinetobacter baumannii have emerged as a major cause of nosocomial infections associated with significant morbidity and mortality. Over the last 20 years a worldwide expansion in Acinetobacter infections has been observed associated with intensive care units (ICUs), long term care facilities and wounded armed forces personnel. The developing resistance patterns seen in Acinetobacter sp suggest that the number of effective antibiotics may shortly be exhau...

  11. Successful Eradication of Multidrug Resistant Acinetobacter in the Helsinki Burn Centre.

    Lindford, Andrew; Kiuru, Valtteri; Anttila, Veli-Jukka; Vuola, Jyrki

    2015-01-01

    Multidrug-resistant (MDR) Acinetobacter is an important pathogen implicated in nosocomial infections in healthcare environments. Virulence factors, resistance mechanisms, and limited therapeutic options make this pathogen a major problem currently facing burn intensive care units (ICUs) worldwide. The purpose of this study was to assess the effect of infection control measures taken in Helsinki Burn Centre in 2001 on MDR Acinetobacter prevalence in ICU burn patients. Data were retrospectively collected from patient files from 1998 to 2012. ICU burn patients were defined as those with either over 30% of total body surface area burnt or requiring mechanical ventilation. Inclusion criteria consisted of patients who tested positive for Acinetobacter sp. in routine bacterial cultures or cultures taken because of a clinically suspected infection. Infection control interventions performed in 2001 consisted of various shower room renovations and changes in hospital hygiene and burn treatment regimes. Between 1998 and 2012, 75 patients were diagnosed with Acinetobacter sp. colonization. Following the infection control interventions the incidence of Acinetobacter sp. radically declined. Between 1998 and 2001, there were 31 cases of MDR Acinetobacter colonizations diagnosed, but from 2002 to 2012 no MDR strains were found. Changes to hospital hygiene and wound treatment protocols as well as structural changes to the hospital environment can have a major impact on preventing and treating Acinetobacter outbreaks in burn centers. PMID:25501783

  12. Serotyping of Acinetobacter calcoaceticus.

    B. C. DAS; Ayliffe, G

    1984-01-01

    Serotyping of Acinetobacter calcoaceticus by direct immunofluorescence and a capsule swelling reaction is described. One hundred isolates, including 12 from an outbreak in a neonatal department, were studied. Ninety five per cent of the isolates were typable by immunofluorescence and could be divided into 30 separate types, but 42.1% of typable strains, including 11 from the outbreak, were of one type. Typing results by the capsular swelling reaction generally followed those of immunofluoresc...

  13. Proteome Analysis of the Adaptation of a Phenol-Degrading Bacterium Acinetobacter sp. EDP3 to the Variation of Phenol Loadings%蛋白质组学方法分析不同苯酚浓度下菌株Acinetobacter sp.EDP3的应激机理

    2007-01-01

    Strain EDP3 was isolated from an industrial-activated sludge. It belonged to the gamma group of Proteobacteria with an identity of 97.0% to Acinetobacter calcoaceticus according to the 1 6S rRNA gene sequences. It can tolerate up to 1000mg.L-1 phenol at room temperature with a much longer lag phase. This indicates that higher phenol concentration has induced some physiological and genotypic changes in the bacterium. The aim of this study is,therefore,to investigate these responses to phenol concentration variations in strain EDP3. Proteome analysis is conducted by means of a two-dimensional polyacrylamide gel electrophoresis (2D PAGE) and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) was conducted to obtain a deeper insight into the adaptive responses inside the bacterium. Comparative analysis of the proteome profiles of strain EDp3 the higher phenol concentration,oxidative stress proteins were dominant. The synthesis of a heat shock protein,600O0 chaperonin GroEL,was also amplified. In addition,the expression of one membrane protein,adenosine 5'-triphosphate (ATP)-binding cassette (ABC) type sugar transporter,was found up-regulated. The inhibition of adenosine 5'-triphosphate (ATP) and RNA/protein synthesis was also observed.

  14. Weigle Reactivation in Acinetobacter Calcoaceticus

    Berenstein, Dvora

    1982-01-01

    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 ...

  15. Weigle Reactivation in Acinetobacter Calcoaceticus

    Berenstein, Dvora

    1982-01-01

    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...

  16. Isolation and Characterization of Fipronil Degrading Acinetobacter calcoaceticus and Acinetobacter oleivorans from Rhizospheric Zone of Zea mays.

    Uniyal, Shivani; Paliwal, Rashmi; Verma, Megha; Sharma, R K; Rai, J P N

    2016-06-01

    An enrichment culture technique was used for the isolation of bacteria capable of utilizing fipronil as a sole source of carbon and energy. Based on morphological, biochemical characteristics and phylogenetic analysis of 16S rRNA sequence, the bacterial strains were identified as Acinetobacter calcoaceticus and Acinetobacter oleivorans. Biodegradation experiments were conducted in loamy sand soil samples fortified with fipronil (50 µg kg(-1)) and inoculated with Acinetobacter sp. cells (45 × 10(7) CFU mL(-1)) for 90 days. Soil samples were periodically analyzed by gas liquid chromatography equipped with electron capture detector. Biodegradation of fipronil fitted well with the pseudo first-order kinetics, with rate constant value between 0.041 and 0.051 days(-1). In pot experiments, fipronil and its metabolites fipronil sulfide, fipronil sulfone and fipronil amide were found below quantifiable limit in soil and root, shoot and leaves of Zea mays. These results demonstrated that A. calcoaceticus and A. oleivorans may serve as promising strains in the bioremediation of fipronil-contaminated soils. PMID:27084098

  17. Reservoirs of Non-baumannii Acinetobacter Species

    Al Atrouni, Ahmad; Joly-Guillou, Marie-Laure; Hamze, Monzer; Kempf, Marie

    2016-01-01

    Acinetobacter spp. are ubiquitous gram negative and non-fermenting coccobacilli that have the ability to occupy several ecological niches including environment, animals and human. Among the different species, Acinetobacter baumannii has evolved as global pathogen causing wide range of infection. Since the implementation of molecular techniques, the habitat and the role of non-baumannii Acinetobacter in human infection have been elucidated. In addition, several new species have been described....

  18. Reservoirs of Non-baumannii Acinetobacter Species.

    Al Atrouni, Ahmad; Joly-Guillou, Marie-Laure; Hamze, Monzer; Kempf, Marie

    2016-01-01

    Acinetobacter spp. are ubiquitous gram negative and non-fermenting coccobacilli that have the ability to occupy several ecological niches including environment, animals and human. Among the different species, Acinetobacter baumannii has evolved as global pathogen causing wide range of infection. Since the implementation of molecular techniques, the habitat and the role of non-baumannii Acinetobacter in human infection have been elucidated. In addition, several new species have been described. In the present review, we summarize the recent data about the natural reservoir of non-baumannii Acinetobacter including the novel species that have been described for the first time from environmental sources and reported during the last years. PMID:26870013

  19. Extremotolerant survival and proteomics of Acinetobacter isolated from spacecraft assembly facilities

    Mogul, Rakesh; Vaishampayan, Parag; Venkateswaran, Kasthuri; McCoy, Kelly; Derecho, Ivy; Dallal, Freida

    2012-07-01

    Herein, we report on the extreme hydrogen peroxide resistance of Acinetobacter isolated from the assembly facilities for the Mars Odyssey orbiter and Phoenix lander. Specific activity experiments on 10 different spacecraft-associated Acinetobacter strains show that the catalase contents are 15-250-fold greater than that of E. coli. Among this group, the highest and lowest catalase-containing strains, which were Acinetobacter nov. sp. 2P01AA and Acinetobacter radioresistens 50v1, demonstrated no significant and 2-log reductions in survivability upon exposure to 100 mM hydrogen peroxide (1 hr), respectively. These survivals are among the highest reported for non-spore forming Gram-negative bacteria. Comparative proteomics on these strains reveals that alkyl hydroperoxide reductase, ATP synthase, dihydrolipoamide dehydrogenase, and peptidyl-tRNA hydrolase also contribute to the hydrogen peroxide extremotolerance. Together, the survival and metabolic features of the spacecraft-associated Acinetobacter indicate that survival in the dry and low-nutrient environments of clean rooms is supported by factors such as oxidant degradation, energy management, and protein biosynthesis.

  20. PHYSICOCHEMICAL AND STRUCTURAL STUDIES ON ACINETOBACTER-CALCOACETICUS RAG-1 AND MR-481 - 2 STANDARD STRAINS IN HYDROPHOBICITY TESTS

    VANDERMEI, HC; COWAN, MM; BUSSCHER, HJ

    1991-01-01

    Acinetobacter calcoaceticus RAG-1 and MR-48 1, two standard strains used in microbial adhesion to hydrocarbons (MATH), were characterized by contact angles, pH-dependent zeta potentials, elemental surface composition by X-ray photoelectron spectroscopy (XPS), and molecular composition by infrared sp

  1. Acinetobacter baumannii em meio hospitalar

    Silveira, Maria José da Costa Pinho

    2011-01-01

    A espécie Acinetobacter baumannii é um microrganismo multirresistente, frequentemente associado a surtos e infecções nos cuidados de saúde. A presença de uma grande variedade de factores determinantes na resistência aos antibióticos, juntamente com a sua capacidade de regular esses mecanismos e se adaptar sob condições ambientais adversas, faz com que esta espécie seja centro de preocupação para a Saúde pública. A sua disseminação na maior parte das vezes clonal, dentro das ...

  2. Culturable populations of Acinetobacter can promptly respond to contamination by alkanes in mangrove sediments.

    Rocha, Lidianne L; Colares, Geórgia B; Angelim, Alysson L; Grangeiro, Thalles B; Melo, Vânia M M

    2013-11-15

    This study evaluated the potential of bacterial isolates from mangrove sediments to degrade hexadecane, an paraffin hydrocarbon that is a large constituent of diesel and automobile lubricants. From a total of 18 oil-degrading isolates obtained by an enrichment technique, four isolates showed a great potential to degrade hexadecane. The strain MSIC01, which was identified by 16S rRNA gene sequencing as Acinetobacter sp., showed the best performance in degrading this hydrocarbon, being capable of completely degrading 1% (v/v) hexadecane within 48 h without releasing biosurfactants. Its hydrophobic surface probably justifies its potential to degrade high concentrations of hexadecane. Thus, the sediments from the studied mangrove harbour bacterial communities that are able to use oil as a carbon source, which is a particularly interesting feature due to the risk of oil spills in coastal areas. Moreover, Acinetobacter sp. MSIC01 emerged as a promising candidate for applications in bioremediation of contaminated mangrove sediments. PMID:24050127

  3. CARBAPENEM-RESISTANT ACINETOBACTER BAUMANII POSTOPERATIVE MENINGITIS

    Laura Ghibu

    2011-02-01

    Full Text Available 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 fatal outcome.

  4. CARBAPENEM-RESISTANT ACINETOBACTER BAUMANII POSTOPERATIVE MENINGITIS

    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...

  5. Isolation and characterization of a novel n-alkane-degrading strain, Acinetobacter haemolyticus AR-46

    Bihari, Z.; Balazs, M.; Bartos, P.; Kesserue, P.; Kiss, I.; Mecs, I. [Bay Zoltan Foundation for Applied Research, Szeged (Hungary). Inst. for Biotechnology; Pettko-Szandtner, A. [Hungarian Academy of Sciences, Szeged (Hungary). Inst. of Plant Biology; Csanadi, G. [Szeged Univ. (Hungary). Dept. of Biotechnology

    2007-03-15

    Strain AR-46, isolated and identified as Acinetobacter haemolyticus, evolutionally distant from the known hydrocarbon-degrading Acinetobacter spp., proved to have excellent long-chain n-alkane-degrading ability. This is the first detailed report on an n-alkane-utilizing strain belonging to this species. The preferred substrate is n-hexadecane, with an optimal temperature of 37 C under aerobic conditions. Five complete and two partial open reading frames were sequenced and correlated with the early steps of monoterminal oxidation-initiated n-alkane mineralization. The encoded protein sequences and the arrangement of these genes displayed high similarity to those found in Acinetobacter sp. M-1, but AR-46 seemed to have only one alkane hydroxylase gene, with a completely different induction profile. Unique behaviour was also observed in n-alkane bioavailability. Substrate uptake occurred through the hydrophobic surface of n-alkane droplet-adhered cells possessing long, thick fimbriae, which were presumed to play a major role in n-alkane solubilization. A majority of the cells was in detached form, with thick, but short fimbriae. These free cells were permanently hydrophilic, unlike the cells of other Acinetobacter strains. (orig.)

  6. Multi-drug resistant Acinetobacter ventilator-associated pneumonia

    Shete, Vishal B.; Dnyaneshwari P Ghadage; Vrishali A Muley; Bhore, Arvind V.

    2010-01-01

    Background: Ventilator-associated pneumonia (VAP) due to a multi-drug resistant (MDR) Acinetobacter is one of the most dreadful complications, which occurs in the critical care setting. Aims and objectives: To find out the incidence of Acinetobacter infection in VAP cases, to determine various risk factors responsible for acquisition of Acinetobacter infection and to determine the antimicrobial susceptibility pattern of Acinetobacter. Materials and Methods: A total of 60 endotracheal aspirate...

  7. Acinetobacter infections prevalence and frequency of the antibiotics resistance: comparative study of intensive care units versus other hospital units

    Uwingabiye, Jean; Frikh, Mohammed; Lemnouer, Abdelhay; Bssaibis, Fatna; Belefquih, Bouchra; Maleb, Adil; Dahraoui, Souhail; Belyamani, Lahcen; Bait, Abdelouahed; Haimeur, Charki; Louzi, Lhoussain; Ibrahimi, Azeddine; Elouennass, Mostafa

    2016-01-01

    Introduction This study aims to determine the Acinetobacter sp clinical isolates frequency and its antibiotic susceptibility pattern by comparing results obtained from the Intensive Care Units (ICUs) to that of other units at the Mohammed V Military Teaching Hospital in Rabat. Methods This is a retrospective study over a 2-years period where we collected all clinical isolates of Acinetobacter sp obtained from samples for infection diagnosis performed on hospitalized patients between 2012 to 2014. Results During the study period, 441 clinical and non-repetitive isolates of Acinetobacter sp were collected representing 6.94% of all bacterial clinical isolates (n = 6352) and 9.6% of Gram negative rods (n = 4569). 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 cultures (14.51%). The resistance to ciprofloxacin, ceftazidime, piperacillin / tazobactam, imipenem, amikacin, tobramycin, netilmicin, rifampicin and colistin was respectively 87%, 86%, 79%, 76%; 52%, 43%, 33% 32% and 1.7%. The difference in resistance between the ICUs and the other units was statistically significant (p <0.05) except for colistin, tetracycline and rifampicin. Conclusion This paper shows that solving the problem of prevalence and high rate of multidrug resistant Acinetobacter infection which represents a therapeutic impasse, requires the control of the hospital environment and optimizing hands hygiene and antibiotics use in the hospital. PMID:27347280

  8. NOSOCOMIAL ACINETOBACTER INFECTIONS IN INTENSIVE CARE UNIT

    Nwadike V. Ugochukwu

    2013-01-01

    Full Text Available Acinetobacter plays an important role in the infection of patients admitted to hospitals. Acinetobacter are free living gram-negative coccobacilli that emerge as significant nosocomial pathogens in the hospital setting and are responsible for intermittent outbreaks in the Intensive Care Unit. The aim of this study was to determine the prevalence of Acinetobacter in patients admitted into the Intensive Care Unit and determine their role in infections in the ICU. A total of one hundred patients were recruited for the study, catheter specimen urine, tracheal aspirate and blood culture were collected aseptically from the patients. The specimens were cultured on blood and MacConkey and the organisms identified using Microbact 12E (0xoid. The Plasmid analysis was done using the TENS miniprep method. Fourteen (14% of the 100 patients recruited into the study, developed Acinetobacter infection. Acinetobacter spp constituted 9% of the total number of isolates. Twelve (86% of the isolates were recovered from tracheal aspirate, 1(7% from urine and 1(7% from blood. All of the isolates harbor plasmids of varying molecular sizes. Ten of the fourteen Acinetobacter were isolated at about the same period of time in the ICU with 6(42.7% having plasmid size in the 23.1kb band and all showed similar pattern revealing that the isolates exhibit some relatedness. The clonal nature of the isolates suggest that strict infection control practices must be adopted in ICU, also an antibiotic policy must be developed for the ICU to prevent abuse of antibiotics that may lead to selection of resistant bacteria.

  9. Effects of Water Miscible Organic Solvents on the Activity and Conformation of the Baeyer-Villiger Monooxygenases From Thermobifida fusca and Acinetobacter calcoaceticus : A Comparative Study

    Secundo, Francesco; Fiala, Stefano; Fraaije, Marco W.; de Gonzalo, Gonzalo; Meli, Massimiliano; Zambianchi, Francesca; Ottolina, Gianluca

    2011-01-01

    A broader exploitation of enzymes in organic synthesis can be achieved by increasing their tolerance toward organic solvents. In this study, the stability and activity of Baeyer-Villiger monooxygenases from Thermobifida fusca (PAMO) and Acinetobacter sp. (CHMO) in the presence of water miscible orga

  10. An Acinetobacter trimeric autotransporter adhesin reaped from cells exhibits its nonspecific stickiness via a highly stable 3D structure

    Shogo Yoshimoto; Hajime Nakatani; Keita Iwasaki; Katsutoshi Hori

    2016-01-01

    Trimeric autotransporter adhesins (TAAs), cell surface proteins of Gram-negative bacteria, 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. AtaA is a homotrimer of polypeptides comprising 3,630 amino acids and forms long nanofibers; therefore, it is too large and structurally complex to be produced...

  11. Antimicrobial resistance and clonality in Acinetobacter baumannii

    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

  12. Advances in diagnosis and treatment of pulmonary infection with Acinetobacter

    Yi SHI

    2011-08-01

    Full Text Available Acinetobacter,especially Acinetobacter baumannii has emerged in recent years as a major cause of nosocomial infections,especially in intensive care units(ICUs,due to its multidrug-resistance(MDR even pan-drug-resistance(PDR characteristics.Acinetobacter infection may lead to high mortality,and it is serious and detrimental to patients.In the year 2009,CHINET antimicrobial surveillance showed that lung was the most commonly infected organ,and SENTRY antimicrobial surveillance showed that Acinetobacter had become the top fifth cause of hospital-acquired pneumonia(HAP,and its antibiotic resistance had gradually increased in these years.Colonization or infection of Acinetobacter should be determined at once when the bacteria were detected from culture of respiratory secretions.Generally,antibacterial treatment is not recommended if no clinical symptoms appear or imaging evidence unavailable.Since the resistance rate of Acinetobacter baumannii to most of the antibiotics reached 50% and above,an effective antibiotics should be carefully selected based on susceptibility test.Sulbactam or sulbactam-based composition is recommended for the carbapenem-resistant bacteria infection,particularly for infections caused by pan-resistant strains.As the first glycylcycline was approved to use in clinic,the anti-bacterial activity of Tigecycline against anti-carbapenem-resistant Acinetobacter has already been proven in vitro.In addition,the most important measure in controlling Acinetobacter pneumonia is to prevent the outbreak of Acinetobacter in medical institutions.

  13. Phosphate uptake kinetics by Acinetobacter isolates.

    Pauli, A S; Kaitala, S

    1997-02-01

    Acinetobacter isolates from activated sludge treatment plants of forest industry were used as model organisms for polyphosphate accumulating bacteria to study excess phosphate uptake by the overplus phenomenon as well as luxury uptake of phosphate during growth. The initial, rapid phosphate uptake by the phosphorus-starved Acinetobacter isolates (the overplus phenomenon) followed the Michaelis-Menten model (maximum initial phosphate uptake rate 29 mg P g(-1) dry mass (DM) h(-1), half-saturation constant for excess phosphate uptake 17 mg P L(-1)). During the rapid uptake no growth was observed, but most cells contained polyphosphate granules. Also growth and luxury uptake of phosphate could be modeled with the Michaelis-Menten equation (maximum phosphate uptake rate 3.7-12 mg P g(-1) DM h(-1), half-saturation constant for growth 0.47-6.0 mg P L(-1), maximum specific growth rate 0.15-0.55 h(-1)). PMID:18633985

  14. Antimicrobial resistance and clonality in Acinetobacter baumannii

    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 vast majority of multidrug resistant (MDR) clinical isolates of A. baumannii from CR belong to clonal lineages termed EU clone I and II; (ii) these two clones have predominated among MDR hospital ...

  15. Iron and Acinetobacter baumannii Biofilm Formation

    Valentina Gentile; Emanuela Frangipani; Carlo Bonchi; Fabrizia Minandri; Federica Runci; Paolo Visca

    2014-01-01

    Acinetobacter baumannii is an emerging nosocomial pathogen, responsible for infection outbreaks worldwide. The pathogenicity of this bacterium is mainly due to its multidrug-resistance and ability to form biofilm on abiotic surfaces, which facilitate long-term persistence in the hospital setting. Given the crucial role of iron in A. baumannii nutrition and pathogenicity, iron metabolism has been considered as a possible target for chelation-based antibacterial chemotherapy. In this study, w...

  16. Mortality audit of neonatal sepsis secondary to Acinetobacter

    Anuradha S De

    2013-01-01

    Full Text Available Background: Multidrug resistant Acinetobacter infection has emerged as an important pathogen in neonatal sepsis in the recent years causing morbidity as well as mortality. Materials and Methods: A retrospective analysis was performed over a one and a half year period of all neonates admitted with sepsis in our neonatal intensive care unit (NICU, who developed Acinetobacter infection and to identify mortality-associated risk factors in these neonates. Results: Incidence of neonatal septicaemia due to Acinetobacter species was 9.18%. All were cases of early onset sepsis. Predominant species isolated was Acinetobacter baumanii (67.5%. The major symptoms were lethargy and poor feeding. The major signs were tachypnoea, rib retraction, and respiratory distress. The major fetal risk factors were low birth weight and prematurity. Overall, 53.75% were multidrug resistant (MDR Acinetobacter. Resistance to more than two drugs (MDR was statistically significant in A. baumanii as compared with nonbaumanii. Overall mortality due to Acinetobacter neonatal sepsis was 20%. Septicemia due to A. baumanii was associated with higher mortality than those due to nonbaumanii isolates. Lethargy, tachypnoea, rib retraction, tachycardia, respiratory distress, and mechanical ventilation were significant predictors of mortality. Conclusion: Multidrug resistant Acinetobacter infection is fatal, particularly in premature and low birth weight neonates. Therefore, an effective infection control policy and rational antibiotic use are mandatory in neonatal intensive care areas of each hospital in order to control Acinetobacter infection and improve outcome.

  17. Development of immunization trials against Acinetobacter baumannii

    Tarek A. Ahmad

    2016-01-01

    Full Text Available Acinetobacter baumannii has recently crossed all lines once considered harmless, pushing its way as a nosocomial pathogen. It had acquired resistance to almost all available chemotherapies and mainly targets intensive care residents; causing pneumonia and major outbreaks with high mortality rates. This urged the need for preventive methods, which include infection control, non-specific immune-therapy, passive, and active immunization in order to offer vulnerable immune-compromised patients a flare in the dark. Several attempts were done for constructing effective vaccines with promising results. These are precisely classified, documented, and discussed in this up-to-date review.

  18. Multi-drug resistant Acinetobacter ventilator-associated pneumonia

    Shete Vishal

    2010-01-01

    Full Text Available Background: Ventilator-associated pneumonia (VAP due to a multi-drug resistant (MDR Acinetobacter is one of the most dreadful complications, which occurs in the critical care setting. Aims and objectives: To find out the incidence of Acinetobacter infection in VAP cases, to determine various risk factors responsible for acquisition of Acinetobacter infection and to determine the antimicrobial susceptibility pattern of Acinetobacter. Materials and Methods: A total of 60 endotracheal aspirate specimens from intubated patients diagnosed clinically and microscopically as VAP were studied bacteriologically. All clinical details and prior exposure to antibiotics were recorded. Results: An incidence of 11.6% of Acinetobacter VAP cases was recorded. Various underlying conditions like head injury, cerebral hemorrhage and chronic obstructive pulmonary disease (COPD were found to be associated with Acinetobacter VAP. Acinetobacter strains exhibited MDR pattern. Conclusion: Strict infection control measures, judicious prescribing of antibiotics, antibiotic resistance surveillance programs and antibiotic cycling should be adopted to control infections due to these bacteria in patients admitted to intensive care units.

  19. Nanoparticles for Control of Biofilms of Acinetobacter Species

    Richa Singh

    2016-05-01

    Full Text Available Biofilms are the cause of 80% of microbial infections. Acinetobacter species have emerged as multi- and pan-drug-resistant bacteria and pose a great threat to human health. These act as nosocomial pathogens and form excellent biofilms, both on biotic and abiotic surfaces, leading to severe infections and diseases. Various methods have been developed for treatment and control of Acinetobacter biofilm including photodynamic therapy, radioimmunotherapy, prophylactic vaccines and antimicrobial peptides. Nanotechnology, in the present scenario, offers a promising alternative. Nanomaterials possess unique properties, and multiple bactericidal mechanisms render them more effective than conventional drugs. This review intends to provide an overview of Acinetobacter biofilm and the significant role of various nanoparticles as anti-biofouling agents, surface-coating materials and drug-delivery vehicles for biofilm control and treatment of Acinetobacter infections.

  20. Improved Triacylglycerol Production in Acinetobacter baylyi ADP1 by Metabolic Engineering

    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.

  1. Antibiotic Resistance in Acinetobacter Baumannii Strains Isolated from Nosocomial Infections

    Pinar Korkmaz

    2016-01-01

    Aim: Acinetobacter baumannii is an opportunistic nosocomial pathogen and one of the most important multidrug-resistant microorganisms in hospitals worldwide. A.baumannii most commonly causes ventilator-associated pneumonia and blood stream infections and mortality rates in these infections can reach 35%. In this study, it was aimed to assess the frequency of Acinetobacter baumannii species which were considered to be causative agents of nosocomial infection and their resistance to antimicrobi...

  2. Mortality audit of neonatal sepsis secondary to Acinetobacter

    Anuradha S; Madhuri R Rathi; Mathur, Meenakshi M

    2013-01-01

    Background: Multidrug resistant Acinetobacter infection has emerged as an important pathogen in neonatal sepsis in the recent years causing morbidity as well as mortality. Materials and Methods: A retrospective analysis was performed over a one and a half year period of all neonates admitted with sepsis in our neonatal intensive care unit (NICU), who developed Acinetobacter infection and to identify mortality-associated risk factors in these neonates. Results: Incidence of neonatal septicaemi...

  3. Genome sequencing and annotation of Acinetobacter junii strain MTCC 11364

    Indu Khatri

    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 3.5 Mb draft genome of the Acinetobacter junii strain MTCC 11364. The genome has a G + C content of 38.0% and includes 3 rRNA genes (5S, 23S, 16S and 64 aminoacyl-tRNA synthetase genes.

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

    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.

  5. Genotypic analysis of Acinetobacter bloodstream infection isolates in a Turkish university hospital.

    Alp, E.; Esel, D.; Yildiz, O.; Voss, A.; Melchers, W.J.G.; Doganay, M.

    2006-01-01

    Acinetobacter baumannii is a significant pathogen of bloodstream infections in hospital patients that frequently causes single clone outbreaks. We aimed to evaluate the genetic relatedness and antimicrobial susceptibility of Acinetobacter spp. bloodstream isolates, in order to obtain insight into th

  6. Acinetobacter infections as an emerging threat in intensive care units

    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)

  7. Multi-drug resistant Acinetobacter ventilator-associated pneumonia

    Shete Vishal; Ghadage Dnyaneshwari; Muley Vrishali; Bhore Arvind

    2010-01-01

    Background: Ventilator-associated pneumonia (VAP) due to a multi-drug resistant (MDR) Acinetobacter is one of the most dreadful complications, which occurs in the critical care setting. Aims and objectives: To find out the incidence of Acinetobacter infection in VAP cases, to determine various risk factors responsible for acquisition of Acinetobacter infection and to determine the antimicrobial susceptibility pattern of Acinetobacter. Materials and Methods: A total of 60 endotracheal aspirate...

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

    Purti C Tripathi; Sunita R Gajbhiye; Gopal Nandlal Agrawal

    2014-01-01

    Background: Recently, Acinetobacter has emerged as significant hospital pathogen, notoriously known to acquire antibiotic resistance to most of the commonly prescribed antimicrobials. Many risk factors are associated with Acinetobacter infections, especially in patients in intensive care unit (ICU). This study aims to isolate Acinetobacter from various clinical specimens and to determine its antimicrobial sensitivity pattern. Materials and Methods: Identification, speciation and antimicro...

  9. Iron and Acinetobacter baumannii Biofilm Formation

    Valentina Gentile

    2014-08-01

    Full Text Available Acinetobacter baumannii is an emerging nosocomial pathogen, responsible for infection outbreaks worldwide. The pathogenicity of this bacterium is mainly due to its multidrug-resistance and ability to form biofilm on abiotic surfaces, which facilitate long-term persistence in the hospital setting. Given the crucial role of iron in A. baumannii nutrition and pathogenicity, iron metabolism has been considered as a possible target for chelation-based antibacterial chemotherapy. In this study, we investigated the effect of iron restriction on A. baumannii growth and biofilm formation using different iron chelators and culture conditions. We report substantial inter-strain variability and growth medium-dependence for biofilm formation by A. baumannii isolates from veterinary and clinical sources. Neither planktonic nor biofilm growth of A. baumannii was affected by exogenous chelators. Biofilm formation was either stimulated by iron or not responsive to iron in the majority of isolates tested, indicating that iron starvation is not sensed as an overall biofilm-inducing stimulus by A. baumannii. The impressive iron withholding capacity of this bacterium should be taken into account for future development of chelation-based antimicrobial and anti-biofilm therapies.

  10. A case of community-acquired Acinetobacter junii-johnsonii cellulitis.

    Henao-Martínez, Andrés F; González-Fontal, Guido R; Johnson, Steven

    2012-06-01

    Acinetobacter skin and soft tissue infection outside of the traumatic wound setting are rare occurrences. The majority of cases occur in the presence of significant comorbilities and by Acinetobacter baumanii. Herein a case is reported of community-onset, health-care-associated, non-traumatic cellulitis caused by Acinetobacter, species junii-johnsonii with bacteremia. This is the first reported case of Acinetobacter junii-johnsonii skin and soft tissue infection. Hemorrhagic bullae might be one of the clinical features of Acinetobacter cellulitis. PMID:23242290

  11. Acinetobacter peritoneal dialysis peritonitis: a changing landscape over time.

    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.

  12. Exploring the diversity of Acinetobacter populations in river water with genus-specific primers and probes.

    Xin, Fangfang; Cai, Dijie; Sun, Yuhua; Guo, Dalei; Wu, Zirong; Jiang, Deming

    2014-01-01

    This study aimed to explore the diversity of river water Acinetobacter populations using culture-dependent and -independent methods. Pyrosequencing indicated that 1.5% of the total sequences from Qiandeng River water were classified as Acinetobacter. Twelve Acinetobacter strains were isolated from three different sampling sites of the Qiandeng River. Based on culture-dependent methods, A. johnsonii, A. lwoffii and A. guillouiae were the most abundantly represented Acinetobacter strains among the upper, middle and downstream populations of the river. Probing of three Acinetobacter-enriched 16S rRNA gene libraries with the Acinetobacter specific probe Act660F revealed 42 unique 16S rRNA gene sequences exhibiting a similarity of 94.9-99.9% with the known Acinetobacter strains. Among the uncultured Acinetobacter sequences, 50%, 58.3% and 68.8% of those obtained from upstream sampling site A, middle stream sampling site B and downstream sampling site C were phylogenetically located within Group I. This Group represented the most abundant strains of Acinetobacter populations in river water based on culture-independent methods. The results indicated that culture-independent methods provide more detailed information on the diversity of Acinetobacter populations than that based on culture-dependent methods. Therefore, the development of new and efficient isolation methods to identify uncultured Acinetobacter species is required. PMID:24859862

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

    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.

  14. A Pathogenic Potential of Acinetobacter baumannii-Derived Membrane Vesicles

    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.

  15. Multidrug-Resistant Acinetobacter baumannii in Veterinary Clinics, Germany

    Zordan, Sabrina; Prenger-Berninghoff, Ellen; Weiss, Reinhard; van der Reijden, Tanny; van den Broek, Peterhans; Baljer, Georg; Dijkshoorn, Lenie

    2011-01-01

    An increase in prevalence of multidrug-resistant Acinetobacter spp. in hospitalized animals was observed at the Justus-Liebig-University (Germany). Genotypic analysis of 56 isolates during 2000–2008 showed 3 clusters that corresponded to European clones I–III. Results indicate spread of genotypically related strains within and among veterinary clinics in Germany.

  16. Prophage Induction by Ultraviolet Light in Acinetobacter calcoaceticus

    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...

  17. Characterization of Acinetobacter baumannii biofilm associated components

    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

  18. CarbAcineto NP Test for Rapid Detection of Carbapenemase-Producing Acinetobacter spp.

    Dortet, Laurent; Poirel , Laurent; Errera, Caroline; Nordmann, Patrice

    2014-01-01

    Multidrug-resistant Acinetobacter baumannii isolates, particularly those that produce carbapenemases, are increasingly reported worldwide. The biochemically based Carba NP test, extensively validated for the detection of carbapenemase producers among Enterobacteriaceae and Pseudomonas spp., has been modified to detect carbapenemase production in Acinetobacter spp. A collection of 151 carbapenemase-producing and 69 non-carbapenemase-producing Acinetobacter spp. were tested using the Carba NP t...

  19. CarbAcineto NP test for rapid detection of carbapenemase-producers in Acinetobacter spp.

    Dortet, Laurent; Poirel , Laurent; Errera, Caroline; Nordmann, Patrice

    2014-01-01

    Multidrug-resistant Acinetobacter baumannii isolates, and particularly carbapenemase-producing isolates, are increasingly reported worldwide. The biochemically-based Carba NP test, extensively validated for detection of carbapenemase producers among Enterobacteriaceae and Pseudomonas spp., has been modified for the detection of carbapenemase production in Acinetobacter spp. A collection of 151 carbapenemase-producing and 69 non-carbapenemase producing Acinetobacter spp. using the Carba NP tes...

  20. High genetic diversity among Pseudomonas aeruginosa and Acinetobacter spp. isolated in a public hospital in Brazil

    Vera Lúcia Dias Siqueira; Rosilene Fressatti Cardoso; Rubia Andreia Falleiros de Pádua; Katiany Rizzieri Caleffi-Ferracioli; Cesar Helbel; Adolfo Carlos Barreto Santos; Elisabeth Eyko Aoki; Celso Vataru Nakamura

    2013-01-01

    In Brazil and other regions of the world, Pseudomonas aeruginosa and Acinetobacter spp. have emerged as important agents of nosocomial infection and are commonly involved in outbreaks. The main objective of the present study was to evaluate the genetic relationship among P. aeruginosa and Acinetobacter spp. isolated from patients in a public university hospital in northwestern Paraná, Brazil, and report their antimicrobial resistance profile. A total of 75 P. aeruginosa and 94 Acinetobacter s...

  1. Acinetobacter species identification by using tRNA spacer fingerprinting.

    Ehrenstein, B; Bernards, A T; Dijkshoorn, L.; Gerner-Smidt, P; Towner, K. J.; Bouvet, P J; Daschner, F D; Grundmann, H

    1996-01-01

    Identification of Acinetobacter spp. to the DNA group level by phenotypic techniques is problematic, and there is a need for an alternative identification method for routine use. The present study validated the suitability of a rapid identification technique based on tRNA spacer (tDNA) fingerprinting in comparison with that of a commercially available assay involving carbon source utilization tests (Biolog MicroStation System) for identifying the 21 DNA-DNA hybridization groups belonging to t...

  2. Assessment of Minocycline and Polymyxin B Combination against Acinetobacter baumannii

    Bowers, Dana R.; Cao, Henry; Zhou, Jian; Ledesma, Kimberly R.; Sun, Dongxu; Lomovskaya, Olga; Tam, Vincent H.

    2015-01-01

    Antimicrobial resistance among Acinetobacter baumannii is increasing worldwide, often necessitating combination therapy. The clinical utility of using minocycline with polymyxin B is not well established. In this study, we investigated the activity of minocycline and polymyxin B against 1 laboratory isolate and 3 clinical isolates of A. baumannii. Minocycline susceptibility testing was performed with and without an efflux pump inhibitor, phenylalanine-arginine β-naphthylamide (PAβN). The intr...

  3. Heteroresistance to Colistin in Multidrug-Resistant Acinetobacter baumannii

    Jian LI; Rayner, Craig R; Nation, Roger L; Owen, Roxanne J.; Spelman, Denis; Tan, Kar Eng; Liolios, Lisa

    2006-01-01

    Multidrug-resistant Acinetobacter baumannii has emerged as a significant clinical problem worldwide and colistin is being used increasingly as “salvage” therapy. MICs of colistin against A. baumannii indicate its significant activity. However, resistance to colistin in A. baumannii has been reported recently. Clonotypes of 16 clinical A. baumannii isolates and ATCC 19606 were determined by pulsed-field gel electrophoresis (PFGE), and colistin MICs were measured. The time-kill kinetics of coli...

  4. Antimicrobial susceptibilities of clinical isolates of Acinetobacter baumannii from Singapore.

    Kuah, B G; Kumarasinghe, G; Doran, J.; Chang, H R

    1994-01-01

    The in vitro activities of 17 antimicrobial agents alone or in combination against 70 clinical isolates of Acinetobacter baumannii from Singapore were determined by broth microdilution. The MICs of amoxicillin, ampicillin, ceftazidime, ceftriaxone, gentamicin, and piperacillin for 90% of the strains were > or = 128 micrograms/ml. Addition of sulbactam to ampicillin produced improved activity, whereas adding tazobactam to piperacillin did not. The MICs of amikacin, ciprofloxacin, and imipenem ...

  5. Antibiotic Susceptibilities of Acinetobacter Baumanii Strains Isolated from Clinical Samples

    Harun Aðca

    2013-01-01

         Aim :  In this study it was aimed to investigate the antibiotic susceptibilities of Acinetobacter baumanii strains isolated from various clinical samples sent to Tavsanli State Hospital Microbiology Laboratory retrospectively. Material and Method: All of the cultures were examined for the agent and antibiotic susceptibilities. For the identification of bacteria, various chemical tests and BBL Crystal E/NF (Beckton Dickinson, ABD) system was used. Antibiotic susce...

  6. Properties of polyphosphate: AMP phosphotransferase of Acinetobacter strain 210A.

    Bonting, C F; Kortstee, G J; Zehnder, A J

    1991-01-01

    Polyphosphate:AMP phosphotransferase, an enzyme which catalyzes the phosphorylation of AMP to ADP at the expense of polyphosphate, was purified more than 1,500-fold from Acinetobacter strain 210A by streptomycin sulfate precipitation and by Mono-Q, Phenyl Superose, and Superose column chromatography. Streptomycin sulfate precipitation appeared to be an effective step in the purification procedure. During the following chromatographic steps, there was a 29-fold increase in specific activity bu...

  7. In vitro activity of ceftobiprole against Acinetobacter baumannii clinical isolates

    Marti, Sara; Sánchez-Céspedes, Javier; Espinal, Paula; Vila, Jordi

    2009-01-01

    Abstract Acinetobacter baumannii is a multiresistant opportunistic nosocomial pathogen responsible for outbreaks worldwide. The main infection caused by this microorganism is nosocomial pneumonia, in particular ventilator-associated pneumonia in patients in Intensive Care Units. Treatment of these nosocomial infections is becoming problematic because the level of resistance to antimicrobial agents is rising. Ceftobiprole is a new cephalosporin with activity against Gram-positive an...

  8. Análisis comparativo de islas de resistencia en los genomas de las cepas multirresistentes de acinetobacter baumannii, acinetobacter nosocomialis y acinetobacter pittii aisladas en Colombia

    Uribe Rico, Laura Patricia

    2014-01-01

    Las islas genómicas de resistencia (IGR) constituyen uno de los principales mecanismos genéticos de transferencia horizontal, por los cuales las bacterias causantes de infecciones intrahospitalarias adquieren perfiles de multirresistencia, entre las que se encuentran las especies del género Acinetobacter. En el presente trabajo se realizó la búsqueda de estos elementos genéticos en tres genomas secuenciado de cepas multirresistentes A. baumannii 107m (AB107m), A. nosocomialis 28F (AN28F) y A....

  9. Caracterización de los plásmidos presentes en tres aislamientos multirresistentes de: Acinetobacter baumannii, Acinetobacter nosocomialis y Acinetobacter pittii obtenidos en hospitales colombianos.

    Rodríguez Méndez, Tatiana

    2014-01-01

    En las últimas décadas, el control de las infecciones asociadas al cuidado de la salud causadas por bacterias del género Acinetobacter se ha convertido en un problema global, ya que un gran porcentaje de aislamientos hospitalarios presentan resistencia a la mayoría de antibióticos de uso común, incluyendo: Penicilinas, cefalosporinas, aminoglicósidos, quinolonas, tetraciclinas, cloranfenicol y carbapenémicos; existen gran cantidad de estudios a nivel mundial que relacionan la presencia de ele...

  10. Optimizing the production of Polyphosphate from Acinetobacter towneri

    J. Aravind

    2015-01-01

    Full Text Available Inorganic polyphosphates (PolyP are linear polymers of few to several hundred orthophosphate residues, linked by energy-rich phosphoanhydride bonds. Four isolates had been screened from soil sample. By MALDI-TOF analysis, they were identified as Bacillius cereus, Acinetobacter towneri, B. megaterium and B. cereus. The production of PolyP in four isolates was studied in phosphate uptake medium and sulfur deficient medium at pH 7. These organisms had shown significant production of PolyP after 22h of incubation. PolyP was extracted from the cells using alkaline lysis method. Among those isolates, Acinetobacter towneri was found to have high (24.57% w/w as P accumulation of PolyP in sulfur deficient medium. The media optimization for sulfur deficiency was carried out using Response surface methodology (RSM. It was proven that increase in phosphate level in the presence of glucose, under sulfur limiting condition, enhanced the phosphate accumulation by Acinetobacter towneri and these condition can be simulated for the effective removal of phosphate from wastewater sources.

  11. Antibiotic Susceptibilities of Acinetobacter Baumanii Strains Isolated from Clinical Samples

    Harun Aðca

    2013-01-01

    Full Text Available      Aim :  In this study it was aimed to investigate the antibiotic susceptibilities of Acinetobacter baumanii strains isolated from various clinical samples sent to Tavsanli State Hospital Microbiology Laboratory retrospectively. Material and Method: All of the cultures were examined for the agent and antibiotic susceptibilities. For the identification of bacteria, various chemical tests and BBL Crystal E/NF (Beckton Dickinson, ABD system was used. Antibiotic susceptibilities were investigated according to CLSI criteria on Mueller Hinton agar by disc diffusion method. Results: There were 74 strains isolated and identified as Acinetobacter baumanii. Most of the strains were isolated from  tracheal aspirate specimens (46 % Most of the strains were isolated from nosocomial infections. Antibiotic resistance was high among strains. The most susceptible antibiotic was gentamicin (30%. Discussion: To prevent the development of resistance, antibiotics should be used carefully in appropriate doses and time, empirical  antibiotherapy should be determined for each centre according to resistance rates of the centre and should be regulated according to the antibiogram results. Increasing resistance rates in Acinetobacter strains leads to the usage of new alternative antibiotics.  

  12. Antibiotic Resistance in Acinetobacter Baumannii Strains Isolated from Nosocomial Infections

    Pinar Korkmaz

    2016-01-01

    Full Text Available Aim: Acinetobacter baumannii is an opportunistic nosocomial pathogen and one of the most important multidrug-resistant microorganisms in hospitals worldwide. A.baumannii most commonly causes ventilator-associated pneumonia and blood stream infections and mortality rates in these infections can reach 35%. In this study, it was aimed to assess the frequency of Acinetobacter baumannii species which were considered to be causative agents of nosocomial infection and their resistance to antimicrobial agents between January 2009 and November 2014 in our hospital. Material and Method: The diagnosis of nosocomial A.baumannii infection was made according to Centers for Disease Control and Prevention (CDC criteria. Identification of the microorganisms isolated from the specimens of the patients and antimicrobial susceptibility testing of them were performed by using VITEK 2 ID-AST automated system. Susceptibilities of amikacin, ampicillin-sulbactam, gentamicin, tobramycin, netilmycin, imipenem, meropenem, piperacillin, piperacillin-tazobactam, ceftazidime, ceftriaxone, cefotaxime, ciprofloxacin, levofloxacin, tetracycline, tigecycline, colistin and co-trimoxazole were investigated in the species. SPSS 19,0 program was used for statistical analysis. Results: A total of 308 Acinetobacter species were isolated and these species were obtained more frequently from the clinical samples sent from the intensive care unit (92,9% and deep tracheal aspirate samples (64,6%. When all of the species were evaluated, the most efficient antibiotics were determined to be colistin, tigecycline and netilmycin. The susceptibility rates for colistin, tigecycline and netilmycin were determined to be 92,8%, 85,3% and 82%, respectively. These are followed by tobramycin with a susceptibility rate of 76,4%, gentamicin with a susceptibility rate of 47,8% and amikacin with a susceptibility rate of 46,3%. Discussion: In our study, colistin, tigecycline and netilmycin are the most

  13. Thai ethnomedicinal plants as resistant modifying agents for combating Acinetobacter baumannii infections

    Phatthalung Pinanong

    2012-04-01

    Full Text Available Abstracts Background Acinetobacter baumannii is well-recognized as an important nosocomial pathogen, however, due to their intrinsic resistance to several antibiotics, treatment options are limited. Synergistic effects between antibiotics and medicinal plants, particularly their active components, have intensively been studied as alternative approaches. Methods Fifty-one ethanol extracts obtained from 44 different selected medicinal plant species were tested for resistance modifying agents (RMAs of novobiocin against A. baumannii using growth inhibition assay. Results At 250 μg/ml, Holarrhena antidysenterica, Punica granatum, Quisqualis indica, Terminalia bellirica, Terminalia chebula, and Terminalia sp. that possessed low intrinsic antibacterial activity significantly enhanced the activity of novobiocin at 1 μg/ml (1/8xminimum inhibitory concentration against this pathogen. Holarrhena antidysenterica at 7.8 μg/ml demonstrated remarkable resistant modifying ability against A. baumannii in combination with novobiocin. The phytochemical study revealed that constituents of this medicinal plant contain alkaloids, condensed tannins, and triterpenoids. Conclusion The use of Holarrhena antidysenterica in combination with novobiocin provides an effective alternative treatment for multidrug resistant A. baumannii infections.

  14. Colistin Heteroresistance in Acinetobacter and Its Association with Previous Colistin Therapy▿

    Hawley, Joshua S.; Murray, Clinton K.; Jorgensen, James H.

    2007-01-01

    Colistin heteroresistance has been reported among Acinetobacter isolates; however, its association with prior colistin therapy has not been not described. A population analysis profile identified resistant Acinetobacter subpopulations from colistin-susceptible clinical isolates. The proportion of cells exhibiting heteroresistance was significantly higher among isolates recovered from patients treated with colistin.

  15. Left-Sided Endocarditis Associated with Multi-Drug Resistance Acinetobacter Lwoffii

    Naghmeh Moshtaghi; Abbasali Karimi; Maryam Sotoudeh Anvari; Mohammad Ali Boroumand; Hossein Ahmadi

    2009-01-01

    Acinetobacter lwoffii, an important nosocomial pathogen, is a gram-negative aerobic bacillus that is a component of the normal flora on the skin, oropharynx, and perineum of about 20-25% of healthy individuals. We herein present a case of a 66-year-old man with combined mitral and aortic valve endocarditis associated with multi-drug resistance acinetobacter lowffii bacteremia.

  16. Genetic Environment and Transcription of ampC in an Acinetobacter baumannii Clinical Isolate

    Segal, Heidi; Nelson, E C; Elisha, B. Gay

    2004-01-01

    An ampC gene was cloned from a clinical isolate of Acinetobacter baumannii (strain RAN). DNA sequencing and primer extension studies showed that ampC is transcribed from a promoter contained within a putative insertion sequence element which has been found to abut several different genes in Acinetobacter spp.

  17. Characterization of the Carbapenem-Hydrolyzing Oxacillinase Oxa-58 in an Acinetobacter Genospecies 3 Clinical Isolate▿

    Marti, Sara; Sánchez-Céspedes, Javier; Blasco, M. Dolores; Ruiz, Marc; Espinal, Paula; Alba, Verónica; Fernández-Cuenca, Felipe; Pascual, Alvaro; Vila, Jordi

    2008-01-01

    Based on imipenem resistance in an Acinetobacter genospecies 3 clinical isolate, we were able to identify, for the first time in this genomic species, a plasmid-encoded blaOXA-58 gene that was 100% homologous to the same gene in Acinetobacter baumannii.

  18. Emergence of NDM-1 and OXA-72 producing Acinetobacter pittii clinical isolates in Lebanon

    A. Al Atrouni

    2016-07-01

    Full Text Available Acinetobacter spp. have emerged as global opportunistic pathogen causing a wide range of infections. Emergence of carbapenem resistance in these organisms is a matter of great concern. We report here the first detection of Acinetobacter pittii clinical isolates in Lebanon carrying either the blaNDM-1 or the blaOXA-72 gene.

  19. Survey of Phenantherene Biodegradation's Model inContaminated Soils by Acinetobacter SP

    M Farzadkia; R Rezaei Kalantary; F Rashid Ashmagh; A Joneidy Jafari; R Nabizadeh

    2009-01-01

    Backgrounds and Objectives: Polycyclic aromatic hydrocarbons (PAHs) are a group of hazardous pollutants which have carcinogenic and mutagenic properties and accumulated in environment by different actions, therefore treatment of them is important. Biological treatments are simple and cheep technologies. This technology was recommended as a cost- effective method for treatment of these pollutants. In order to investigate the trend of pollution reduction of petroleum hydrocarbons in bioremediat...

  20. Antimicrobial susceptibilities of clinical isolates of Acinetobacter baumannii from Singapore.

    Kuah, B G; Kumarasinghe, G; Doran, J; Chang, H R

    1994-10-01

    The in vitro activities of 17 antimicrobial agents alone or in combination against 70 clinical isolates of Acinetobacter baumannii from Singapore were determined by broth microdilution. The MICs of amoxicillin, ampicillin, ceftazidime, ceftriaxone, gentamicin, and piperacillin for 90% of the strains were > or = 128 micrograms/ml. Addition of sulbactam to ampicillin produced improved activity, whereas adding tazobactam to piperacillin did not. The MICs of amikacin, ciprofloxacin, and imipenem for 90% of the strains were 32, 32, and 16 micrograms/ml, respectively. PMID:7840598

  1. Drug resistance patterns of acinetobacter baumannii in makkah, saudi arabia

    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)

  2. Acinetobacter baumannii in Localised Cutaneous Mycobacteriosis in Falcons

    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.

  3. Biofilm producing multidrug resistant Acinetobacter species from a tertiary care hospital: a therapeutic challenge

    Manju Bala

    2016-07-01

    Conclusions: This study demonstrates the ability of Acinetobacter isolates to form biofilm and biofilm production has strong association with multiple drug resistance. [Int J Res Med Sci 2016; 4(7.000: 3024-3026

  4. [Problem of treatment for pyo-inflammatory complications caused by Acinetobacter].

    Bogomolova, N S; Bol'shakov, L V; Kuznetsova, S M

    2014-01-01

    The article deals with analysis of a detection frequency and antibacterial treatment resistance of Acinetobacter spp.of different species affiliation. Strains of bacteria detected in patients with pyo-inflammatory complications after surgeries (period from 2010 to 2012) were involved in the study 137 strains of Acinetobacter spp. were detected and studied Fraction of Acinetobacter spp. in 2010, 2011 and 2012 was 2.3, 3 and 3.4% respectively. Fraction of P. aeruginosain all non-fermentative Gram-negative bacteria (NFGNB) decreased by 120% and fraction of Acinetobacter spp. increased by 200-250%. Acinetobacter spp. detection frequency was not significantly changed in the period from 2006 to 2012. However the fraction of Acinetobacter spp. in NFGNB increased by 150% and was 29% in 2012. Detection frequency of A. baumanii sharply increased in 2012. A study of antibacterial treatment resistance of Acinetobacter spp. (10 antibacterial medicines) showed that Polymyxin B and E (Colistin) was the most effective medicine for A. baumanii and A. calcoaceticus infection. 85-95% of Acinetobacter spp.strains kept sensitivity to this antibacterial medicine. 66-88.9% of A. baumanii strains, 66.7-81.8% of A. alcoaceticus and 66.6% of other Acinetobacter spp. were sensitive to Tigecycline. Dioxidine effectiveness was close to Tigecycline in 66.7-80% of A. baumanii strains. 85-100% of A. calcoaceticus strains were sensitive to Dioxidine. There is a trend of decreasing of A. baumanii sensitivity to Carbapenems by 200%. Fraction of strains sensitive to Meropenem and Imipenem in 2012 was 21.4% and 16.7% respectively. All studied strains of A. lwoffi and A. haemolyticus kept sensitivity to Carbapenems. In 2012 23.8% of A. baumanii and 50% of A. calcoaceticus strains were sensitivity to Amikacin, meanwhile A. lwoffi and A. haemolyticus were not sensitive to this medicine. 31.3% of A. baumanii and 50% of A. calcoaceticus strains were sensitive to Ceftazidime/Sulbactam. 5.3% of A. baumanii

  5. Distribution of Acinetobacter species on human skin: comparison of phenotypic and genotypic identification methods.

    Seifert, H.; Dijkshoorn, L; Gerner-Smidt, P; Pelzer, N.; Tjernberg, I; Vaneechoutte, M

    1997-01-01

    At least 19 genomic species are recognized as constituting the genus Acinetobacter. However, little is known about the natural reservoirs of the various members of the genus. An epidemiological study was therefore performed to investigate the colonization with Acinetobacter spp. of the skin and mucous membranes of 40 patients hospitalized in a cardiology ward and 40 healthy controls. Single samples were obtained once from each of nine different body sites, i.e., forehead, ear, nose, throat, a...

  6. The Outcomes of Using Colistin for Treating Multidrug Resistant Acinetobacter Species Bloodstream Infections

    Lim, Seung-Kwan; Lee, Sang-Oh; Choi, Seong-Ho; Choi, Jae-Phil; Kim, Sung-Han; Jeong, Jin-Yong; Choi, Sang-Ho; Woo, Jun Hee; Kim, Yang Soo

    2011-01-01

    Despite the identification of Acinetobacter baumannii isolates that demonstrate susceptibility to only colistin, this antimicrobial agent was not available in Korea until 2006. The present study examined the outcomes of patients with multidrug resistant (MDR) Acinetobacter species bloodstream infection and who were treated with or without colistin as part of their regimen. The colistin group was given colistin as part of therapy once colistin became available in 2006. The non-colistin group w...

  7. Meta-analysis of colistin for the treatment of Acinetobacter baumannii infection

    Zhijin Chen; Yu Chen; Yaogao Fang; Xiaotian Wang; Yanqing Chen; Qingsong Qi; Fang Huang; Xungang Xiao

    2015-01-01

    Multidrug resistant among Acinetobacter baumannii infection is associated with a high mortality rate and limits the therapeutic options. The aim of this study was to assess the safety and efficacy of colistin monotherapy vs. other single antibiotic therapy AND colistin-based combination therapy (with other antibiotics) vs. colistin alone for the treatment of Acinetobacter baumannii infection. Online electronic database were searched for studies evaluating colistin with or without other antibi...

  8. Genome sequencing and annotation of Acinetobacter gerneri strain MTCC 9824T

    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.

  9. Genome sequencing and annotation of Acinetobacter gyllenbergii strain MTCC 11365T

    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.

  10. Comparison of two methods for quantification of Acinetobacter baumannii biofilm formation

    Saghar Hendiani; Ahya Abdi-Ali; Parisa Mohammadi

    2014-01-01

    Introduction: ‏ Medical devices are made from a variety of materials such as polypropylene, polycarbonate, poly styrene, glass and etc. by attaching to this surfaces, Acinetobacter baumannii can form biofilms and then cause several device associated infections. Biofilms are communities of bacteria attached to the surfaces. In this study, biofilm formation ability in clinical isolates of Acinetobacter baumannii was assessed by two methods on different surfaces. Materials and methods: ‏ Biof...

  11. Antimicrobial Susceptibility Testing of Acinetobacter spp. by NCCLS Broth Microdilution and Disk Diffusion Methods

    Swenson, Jana M.; Killgore, George E.; Tenover, Fred C.

    2004-01-01

    Although both broth microdilution (BMD) and disk diffusion (DD) are listed by NCCLS as acceptable methods for testing Acinetobacter spp. for antimicrobial susceptibility, few studies have compared the results generated by the two methods. We tested 196 isolates of Acinetobacter spp. from nine U.S. hospitals and from the Centers for Disease Control culture collection by using BMD and DD and clinically appropriate antimicrobial agents. Categorical results for amikacin, ciprofloxacin, gatifloxac...

  12. Biochemical and Structural Analysis of Inhibitors Targeting the ADC-7 Cephalosporinase of Acinetobacter baumannii

    Powers, Rachel A.; Swanson, Hollister C.; Taracila, Magdalena A.; Florek, Nicholas W.; Romagnoli, Chiara; Caselli, Emilia; Prati, Fabio; Bonomo, Robert A.; Wallar, Bradley J.

    2014-01-01

    β-Lactam resistance in Acinetobacter baumannii presents one of the greatest challenges to contemporary antimicrobial chemotherapy. Much of this resistance to cephalosporins derives from the expression of the class C β-lactamase enzymes, known as Acinetobacter-derived cephalosporinases (ADCs). Currently, β-lactamase inhibitors are structurally similar to β-lactam substrates and are not effective inactivators of this class C cephalosporinase. Herein, two boronic acid transition state inhibitors...

  13. Left-Sided Endocarditis Associated with Multi-Drug Resistance Acinetobacter Lwoffii

    Naghmeh Moshtaghi

    2009-09-01

    Full Text Available Acinetobacter lwoffii, an important nosocomial pathogen, is a gram-negative aerobic bacillus that is a component of the normal flora on the skin, oropharynx, and perineum of about 20-25% of healthy individuals. We herein present a case of a 66-year-old man with combined mitral and aortic valve endocarditis associated with multi-drug resistance acinetobacter lowffii bacteremia.

  14. PHENOTYPIC DETECTION OF CARBAPENEM RESISTANCE IN CLINICAL ISOLATES OF ACINETOBACTER BAUMANII IN KANCHIPURAM

    Sivasankari S; Senthamarai; Anitha C; Apurba Sastry; Sandhya bhatt; Kumudhavathi M.S; Amshavadhani S.K

    2014-01-01

    Acinctobacter species are common non fermentative gram negative bacilli isolated in clinical laboratory most frequently encountered species. Acinetobacter resistance is develop due to acquired resistance. Because of frequent multidrug resistance isolates carbapenems have become important for treating resistant strains. There is a need for rapid screening & detection of MBL in Acinetobacter to modify the treatment. The present study was aim to determine the resistance of A.baumanii complese to...

  15. Carbapenem resistant Acinetobacter baumanii versus MRSA isolates in ICU in Clinical Center Skopje

    Popovska, Katja; Zdravkovska, Milka; Petrovska, Milena; Pollozhani, Azis

    2014-01-01

    Backgorund: Acinetobacter baumannii is often referred to as the “Gram-negative methicillin-resistant Staphylococcus aureus”, because it is frequently resistant to antibiotics. Clonal outbreaks of carbapenem-resistant and OXA-23–producing A. baumannii have been reported worldwide. Aim: The goal of this study was to promote the phenomenon of disbalance in endemic hospital ECO system which included increase of carbapenemase-resistant Acinetobacter baumanii on account of reduction of MRSA rate in...

  16. Prognostic differences between VAP from Acinetobacter baumanii and VAP from other microorganisms

    Di Bonito, Marianna; Caiazzo, Simona; Iannazzone, Marta; Miccichè, Viviana; De Marco, Giuseppe; De Robertis, Edoardo; Tufano, Rosalba; Piazza, Ornella

    2012-01-01

    Nosocomial infection, in particular pneumonia, is an important risk factor for hospital mortality and morbidity. Acinetobacter baumanii is a common multi-resistant microorganism responsible of Ventilator Associated Pneumonia (VAP). Currently Colistin is a rescue therapy for this pathogen. The purpose of this retrospective study is to compare the outcome of VAP caused by Acinetobacter baumanii and VAP from other microorganisms in critical patients. Comorbidity, prognostic scores, mortality and...

  17. Genome sequencing and annotation of Acinetobacter haemolyticus strain MTCC 9819T

    Indu Khatri

    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 3.4 Mb genome of Acinetobacter haemolyticus strain MTCC 9819T. The genome has a G + C content of 40.0% and includes 3 rRNA genes (5S, 23S, 16S and 65 aminoacyl-tRNA synthetase genes.

  18. Functional roles of Tryptophan residues in diketoreductase from Acinetobacter baylyi

    Yan Huang1, Zhuo Lu1, Min Ma1, Nan Liu1 & Yijun Chen1,2,*

    2012-08-01

    Full Text Available Diketoreductase (DKR from Acinetobacter baylyi contains twotryptophan residues at positions 149 and 222. Trp-149 andTrp-222 are located along the entry path of substrate into activesite and at the dimer interface of DKR, respectively. Single anddouble substitutions of these positions were generated to probethe roles of tryptophan residues. After replacing Trp with Alaand Phe, biochemical and biophysical characteristics of themutants were thoroughly investigated. Enzyme activity andsubstrate binding affinity of W149A and W149F wereremarkably decreased, suggesting that Trp-149 regulates theposition of substrate at the binding site. Meanwhile, enzymeactivity of W222F was increased by 1.7-fold while W222A wascompletely inactive. In addition to lower thermostability ofTrp-222 mutants, molecular modeling of the mutants revealedthat Trp-222 is vital to protein folding and dimerization of theenzyme.

  19. Antimicrobial susceptibility of clinical isolates of Acinetobacter baumannii.

    Shi, Z Y; Liu, P Y; Lau, Y; Lin, Y; Hu, B S; Shir J-M

    1996-02-01

    The in-vitro activity of 18 antimicrobial agents alone or in combination against 248 clinical isolates of Acinetobacter baumannii from Taiwan were tested by agar dilution. The MIC90S of ampicillin, amoxicillin, piperacillin, cefuroxime, cefotaxime, ceftriaxone, gentamicin, and amikacin were at least 128 mu g/ml. Ceftazidime, cefepime, sulbactam, clavulanic acid, and tazobactam presented moderate activity with MIC90S of 32, 16, 16, 32, and 32 mu g/ml, respectively. The increased activity of ampicillin/sulbactam, amoxicillin/clavulanic acid, and piperacillin/tazobactam was due to the intrinsic effect of sulbactam, clavulanic acid, and tazobactam, respectively. Imipenem, meropenem, and ciprofloxacin were the most active antimicrobial agents with MIC90S of 1, 1, and 0.5 mu g/ml, respectively. Nineteen isolates (7.7%) were resistant to all aminoglycosides and beta-lactam antibiotics, except carbapenems and ciprofloxacin. We are concerned about the multidrug resistance of A. baumannii in this study. PMID:9147913

  20. Community-acquired Acinetobacter baumannii: clinical characteristics, epidemiology and pathogenesis.

    Dexter, Carina; Murray, Gerald L; Paulsen, Ian T; Peleg, Anton Y

    2015-05-01

    Community-acquired Acinetobacter baumannii (CA-Ab) is a rare but serious cause of community-acquired pneumonia in tropical regions of the world. CA-Ab infections predominantly affect individuals with risk factors, which include excess alcohol consumption, diabetes mellitus, smoking and chronic lung disease. CA-Ab pneumonia presents as a surprisingly fulminant course and is characterized by a rapid onset of fever, severe respiratory symptoms and multi-organ dysfunction, with a mortality rate reported as high as 64%. It is unclear whether the distinct clinical syndrome caused by CA-Ab is because of host predisposing factors or unique bacterial characteristics, or a combination of both. Deepening our understanding of the drivers of overwhelming CA-Ab infection will provide important insights into preventative and therapeutic strategies. PMID:25850806

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

    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)

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

    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)

  3. Antimicrobial susceptibility of Acinetobacter clinical isolates and emerging antibiogram trends for nosocomial infection management

    Muhammad Sohail

    2016-06-01

    Full Text Available Abstract: Introduction: The drug resistant Acinetobacter strains are important causes of nosocomial infections that are difficult to control and treat. This study aimed to determine the antimicrobial susceptibility patterns of Acinetobacter strains isolated from different clinical specimens obtained from patients belonging to different age groups. METHODS: In total, 716 non-duplicate Acinetobacter isolates were collected from the infected patients admitted to tertiary-care hospitals at Lahore, Pakistan, over a period of 28 months. The Acinetobacter isolates were identified using API 20E, and antimicrobial susceptibility testing was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI guidelines. RESULTS: The isolation rate of Acinetobacter was high from the respiratory specimens, followed by wound samples. Antibiotic susceptibility analyses of the isolates revealed that the resistance to cefotaxime and ceftazidime was the most common, in 710 (99.2% specimens each, followed by the resistance to gentamicin in 670 (93.6% isolates, and to imipenem in 651 (90.9% isolates. However, almost all isolates were susceptible to tigecycline, colistin, and polymyxin B. CONCLUSIONS: The present study showed the alarming trends of resistance of Acinetobacter strains isolated from clinical specimens to the various classes of antimicrobials. The improvement of microbiological techniques for earlier and more accurate identification of bacteria is necessary for the selection of appropriate treatments.

  4. Antibiotic Sensitivity Pattern of Blood Isolates of Acinetobacter Species in a Tertiary Care Hospital: A Retrospective Analysis

    P. S. Shareek; Sureshkumar, D; Ramgopalakrishnan; Ramasubramanian, V.; K. A. Ghafur; M. A. Thirunarayanan

    2012-01-01

    Problem statement: Multi-drug resistant Acinetobacter bacterium is one of the major causes of sepsis in ICUs in tertiary care hospitals in India. In this report we describe the antibiotic sensitivity patterns of Acinetobacter species isolated from blood over a one year period at a tertiary care hospital. Approach: We retrospectively analyzed the sensitivity pattern of Acinetobacter species isolated from blood during the period 1/6/2010 to 31/5/2011. Isolation and identification were performed...

  5. Evaluation of adherence, hemagglutination, and presence of genes codifying for virulence factors of Acinetobacter baumannii causing urinary tract infection

    Graziela Braun

    2004-12-01

    Full Text Available Acinetobacter baumannii is a strictly aerobic bacterium which causes severe infections, however its pathogenic characteristics are not well defined. Thirteen A. baumannii strains isolated from urine of hospitalized and nonhospitalized patients with different ages were investigated for the presence of virulence factors. The isolates belonged to biotypes 2, 6, and 9 and were sensitive to imipenem. The majority of them showed resistance to amikacin, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, norfloxacin, and trimethoprim-sulfamethoxazole. None of A. baumannii strains presented genes codifying for 17 different virulence factors previously described in uropathogenic Escherichia coli, when tested by polymerase chain reaction (PCR. Nine isolates agglutinated human group AB erythrocytes, in presence of mannose, but none of them agglutinated group O erythrocytes. Adherence to polystyrene was observed in 7 isolates, and this result did not correlate with that obtained in hemagglutination assay. All the isolates were able to grow in iron-limiting conditions, showing that A. baumannii produces some type of siderophore. However, the genes iutA and fyuA, from iron uptake system of E. coli and Yersinia sp., respectively, were not present in the isolates, suggesting the presence of a different type of siderophore. The fimbriae of A. baumannii strains that mediates the adherence are possibly mannose-resistant, eventhough the mechanism of adherence to human epithelial cells still remains to be elucidated.

  6. Diversity of Acinetobacter baumannii in four French military hospitals, as assessed by multiple locus variable number of tandem repeats analysis.

    Yolande Hauck

    Full Text Available BACKGROUND: Infections by A. calcoaceticus-A. baumannii (ACB complex isolates represent a serious threat for wounded and burn patients. Three international multidrug-resistant (MDR clones (EU clone I-III are responsible for a large proportion of nosocomial infections with A. baumannii but other emerging strains with high epidemic potential also occur. METHODOLOGY/PRINCIPAL FINDINGS: We automatized a Multiple locus variable number of tandem repeats (VNTR analysis (MLVA protocol and used it to investigate the genetic diversity of 136 ACB isolates from four military hospitals and one childrens hospital. Acinetobacter sp other than baumannii isolates represented 22.6% (31/137 with a majority being A. pittii. The genotyping protocol designed for A.baumannii was also efficient to cluster A. pittii isolates. Fifty-five percent of A. baumannii isolates belonged to the two international clones I and II, and we identified new clones which members were found in the different hospitals. Analysis of two CRISPR-cas systems helped define two clonal complexes and provided phylogenetic information to help trace back their emergence. CONCLUSIONS/SIGNIFICANCE: The increasing occurrence of A. baumannii infections in the hospital calls for measures to rapidly characterize the isolates and identify emerging clones. The automatized MLVA protocol can be the instrument for such surveys. In addition, the investigation of CRISPR/cas systems may give important keys to understand the evolution of some highly successful clonal complexes.

  7. An Acinetobacter trimeric autotransporter adhesin reaped from cells exhibits its nonspecific stickiness via a highly stable 3D structure.

    Yoshimoto, Shogo; Nakatani, Hajime; Iwasaki, Keita; Hori, Katsutoshi

    2016-01-01

    Trimeric autotransporter adhesins (TAAs), cell surface proteins of Gram-negative bacteria, 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. AtaA is a homotrimer of polypeptides comprising 3,630 amino acids and forms long nanofibers; therefore, it is too large and structurally complex to be produced as a recombinant protein. In this study, we isolated AtaA's passenger domain (AtaA PSD), which is translocated to the cell surface through the C-terminal transmembrane domain and exhibits biological functions, using a new method. We introduced a protease recognition site and reaped AtaA nanofibers 225 nm in length from the cell surface through proteolytic cleavage with a specific protease. Biochemical and biophysical analyses of the purified native AtaA PSD revealed that it has a stable structure under alkaline and acidic conditions. Temperatures above 80 °C, which disrupted AtaA's higher-order structure but maintained the full-length AtaA polypeptide, inactivated AtaA's nonspecific adhesiveness, suggesting that the stickiness of AtaA requires its 3D structure. This finding refutes the widespread but vague speculation that large unfolded polypeptides readily stick to various surfaces. PMID:27305955

  8. Multidrug resistant Acinetobacter baumannii: a descriptive study in a city hospital

    Pratap Siddharth

    2010-07-01

    Full Text Available Abstract Background Multidrug resistant Acinetobacter baumannii, (MRAB is an important cause of hospital acquired infection. The purpose of this study is to determine the risk factors for MRAB in a city hospital patient population. Methods This study is a retrospective review of a city hospital epidemiology data base and includes 247 isolates of Acinetobacter baumannii (AB from 164 patients. Multidrug resistant Acinetobacter baumannii was defined as resistance to more than three classes of antibiotics. Using the non-MRAB isolates as the control group, the risk factors for the acquisition of MRAB were determined. Results Of the 247 AB isolates 72% (177 were multidrug resistant. Fifty-eight percent (143/247 of isolates were highly resistant (resistant to imipenem, amikacin, and ampicillin-sulbactam. Of the 37 patients who died with Acinetobacter colonization/infection, 32 (86% patients had the organism recovered from the respiratory tract. The factors which were found to be significantly associated (p ≤ 0.05 with multidrug resistance include the recovery of AB from multiple sites, mechanical ventilation, previous antibiotic exposure, and the presence of neurologic impairment. Multidrug resistant Acinetobacter was associated with significant mortality when compared with sensitive strains (p ≤ 0.01. When surgical patients (N = 75 were considered separately, mechanical ventilation and multiple isolates remained the factors significantly associated with the development of multidrug resistant Acinetobacter. Among surgical patients 46/75 (61% grew a multidrug resistant strain of AB and 37/75 (40% were resistant to all commonly used antibiotics including aminoglycosides, cephalosporins, carbepenems, extended spectrum penicillins, and quinolones. Thirty-five percent of the surgical patients had AB cultured from multiple sites and 57% of the Acinetobacter isolates were associated with a co-infecting organism, usually a Staphylococcus or Pseudomonas. As

  9. Comparative genomic analysis of novel Acinetobacter symbionts: A combined systems biology and genomics approach

    Gupta, Vipin; Haider, Shazia; Sood, Utkarsh; Gilbert, Jack A.; Ramjee, Meenakshi; Forbes, Ken; Singh, Yogendra; Lopes, Bruno S.; Lal, Rup

    2016-01-01

    The increasing trend of antibiotic resistance in Acinetobacter drastically limits the range of therapeutic agents required to treat multidrug resistant (MDR) infections. This study focused on analysis of novel Acinetobacter strains using a genomics and systems biology approach. Here we used a network theory method for pathogenic and non-pathogenic Acinetobacter spp. to identify the key regulatory proteins (hubs) in each strain. We identified nine key regulatory proteins, guaA, guaB, rpsB, rpsI, rpsL, rpsE, rpsC, rplM and trmD, which have functional roles as hubs in a hierarchical scale-free fractal protein-protein interaction network. Two key hubs (guaA and guaB) were important for insect-associated strains, and comparative analysis identified guaA as more important than guaB due to its role in effective module regulation. rpsI played a significant role in all the novel strains, while rplM was unique to sheep-associated strains. rpsM, rpsB and rpsI were involved in the regulation of overall network topology across all Acinetobacter strains analyzed in this study. Future analysis will investigate whether these hubs are useful as drug targets for treating Acinetobacter infections. PMID:27378055

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

    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)

  11. Colistin and anti-Gram-positive bacterial agents against Acinetobacter baumannii

    Bin Liu

    2014-07-01

    Full Text Available Introduction Acinetobacter baumannii has attained an alarming level of resistance to antibacterial drugs. Clinicians are now considering the use of older agents or unorthodox combinations of licensed drugs against multidrug-resistant strains to bridge the current treatment gap. We investigated the in vitro activities of combination treatments that included colistin with vancomycin, norvancomycin or linezolid against multidrug-resistant Acinetobacter baumannii. Methods The fractional inhibitory concentration index and time-kill assays were used to explore the combined effects of colistin with vancomycin, norvancomycin or linezolid against 40 clinical isolates of multidrug-resistant Acinetobacter baumannii. Transmission electron microscopy was performed to evaluate the interactions in response to the combination of colistin and vancomycin. Results The minimum inhibitory concentrations (MICs of vancomycin and norvancomycin for half of the isolates decreased below the susceptibility break point, and the MIC of linezolid for one isolate was decreased to the blood and epithelial lining fluid concentration using the current dosing regimen. When vancomycin or norvancomycin was combined with subinhibitory doses of colistin, the multidrug-resistant Acinetobacter baumannii test samples were eradicated. Transmission electron microscopy revealed that subinhibitory doses of colistin were able to disrupt the outer membrane, facilitating a disruption of the cell wall and leading to cell lysis. Conclusions Subinhibitory doses of colistin significantly enhanced the antibacterial activity of vancomycin, norvancomycin, and linezolid against multidrug-resistant Acinetobacter baumannii.

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

    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.

  13. Rapid identification of carbapenemase-producing Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii using a modified Carba NP test

    Bakour, S.; Garcia, V; Loucif, L.; J.-M. Brunel; Gharout-Sait, A.; Touati, A.; J.-M. Rolain

    2015-01-01

    Biochemical tests have been previously developed to identify carbapenemase-producing Enterobacteriaceae, Pseudomonas spp. (Carba NP test) and Acinetobacter spp. (CarbAcineto NP test). We evaluated a modified Carba NP test to detect carbapenemase production in Enterobacteriaceae, Pseudomonas and Acinetobacter species using a single protocol with rapid results and found good reliability and speed.

  14. Rapid identification of carbapenemase-producing Enterobacteriaceae, Pseudomonas aeruginosa and Acinetobacter baumannii using a modified Carba NP test

    S. Bakour

    2015-09-01

    Full Text Available Biochemical tests have been previously developed to identify carbapenemase-producing Enterobacteriaceae, Pseudomonas spp. (Carba NP test and Acinetobacter spp. (CarbAcineto NP test. We evaluated a modified Carba NP test to detect carbapenemase production in Enterobacteriaceae, Pseudomonas and Acinetobacter species using a single protocol with rapid results and found good reliability and speed.

  15. Genomic and phenotypic characterization of the species Acinetobacter venetianus.

    Fondi, Marco; Maida, Isabel; Perrin, Elena; Orlandini, Valerio; La Torre, Laura; Bosi, Emanuele; Negroni, Andrea; Zanaroli, Giulio; Fava, Fabio; Decorosi, Francesca; Giovannetti, Luciana; Viti, Carlo; Vaneechoutte, Mario; Dijkshoorn, Lenie; Fani, Renato

    2016-01-01

    Crude oil is a complex mixture of hydrocarbons and other organic compounds that can produce serious environmental problems and whose removal is highly demanding in terms of human and technological resources. The potential use of microbes as bioremediation agents is one of the most promising fields in this area. Members of the species Acinetobacter venetianus have been previously characterized for their capability to degrade n-alkanes and thus may represent interesting model systems to implement this process. Although a preliminary experimental characterization of the overall hydrocarbon degradation capability has been performed for five of them, to date, the genetic/genomic features underlying such molecular processes have not been identified. Here we have integrated genomic and phenotypic information for six A. venetianus strains, i.e. VE-C3, RAG-1(T), LUH 13518, LUH 7437, LUH 5627 and LUH 8758. Besides providing a thorough description of the A. venetianus species, these data were exploited to infer the genetic features (presence/absence patterns of genes) and the short-term evolutionary events possibly responsible for the variability in n-alkane degradation efficiency of these strains, including the mechanisms of interaction with the fuel droplet and the subsequent catabolism of this pollutant. PMID:26902269

  16. Stereochemical insignificance discovered in Acinetobacter baumannii quorum sensing.

    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.

  17. The structure of alanine racemase from Acinetobacter baumannii

    Davis, Emily; Scaletti-Hutchinson, Emma; Opel-Reading, Helen; Nakatani, Yoshio; Krause, Kurt L.

    2014-01-01

    Acinetobacter baumannii is an opportunistic Gram-negative bacterium which is a common cause of hospital-acquired infections. Numerous antibiotic-resistant strains exist, emphasizing the need for the development of new antimicrobials. Alanine racemase (Alr) is a pyridoxal 5′-phosphate dependent enzyme that is responsible for racemization between enantiomers of alanine. As d-alanine is an essential component of the bacterial cell wall, its inhibition is lethal to prokaryotes, making it an excellent antibiotic drug target. The crystal structure of A. baumannii alanine racemase (AlrAba) from the highly antibiotic-resistant NCTC13302 strain has been solved to 1.9 Å resolution. Comparison of AlrAba with alanine racemases from closely related bacteria demonstrates a conserved overall fold. The substrate entryway and active site of the enzymes were shown to be highly conserved. The structure of AlrAba will provide the template required for future structure-based drug-design studies. PMID:25195891

  18. Stress Conditions Induced by Carvacrol and Cinnamaldehyde on Acinetobacter baumannii.

    Montagu, Angélique; Joly-Guillou, Marie-Laure; Rossines, Elisabeth; Cayon, Jérome; Kempf, Marie; Saulnier, Patrick

    2016-01-01

    Acinetobacter baumannii has emerged as a major cause of nosocomial infections. The ability of A. baumannii to display various resistance mechanisms against antibiotics has transformed it into a successful nosocomial pathogen. The limited number of antibiotics in development and the disengagement of the pharmaceutical industry have prompted the development of innovative strategies. One of these strategies is the use of essential oils, especially aromatic compounds that are potent antibacterial molecules. Among them, the combination of carvacrol and cinnamaldehyde has already demonstrated antibacterial efficacy against A. baumannii. The aim of this study was to determine the biological effects of these two compounds in A. baumannii, describing their effect on the rRNA and gene regulation under environmental stress conditions. Results demonstrated rRNA degradation by the carvacrol/cinnamaldehyde mixture, and this effect was due to carvacrol. Degradation was conserved after encapsulation of the mixture in lipid nanocapsules. Results showed an upregulation of the genes coding for heat shock proteins, such as groES, groEL, dnaK, clpB, and the catalase katE, after exposure to carvacrol/cinnamaldehyde mixture. The catalase was upregulated after carvacrol exposure wich is related to an oxidative stress. The combination of thiourea (hydroxyl radical scavenger) and carvacrol demonstrated a potent bactericidal effect. These results underline the development of defense strategies of the bacteria by synthesis of reactive oxygen species in response to environmental stress conditions, such as carvacrol. PMID:27486453

  19. Identification of KPC-Producing Pseudomonas Aeruginosa and Acinetobacter Baumanniiin a Burned Infant: A Case Report

    Abdolaziz Rastegar Lari

    2012-03-01

    Full Text Available The objective of this study was to determine the phenotypic characteristics of KPC-producing Pseudomonas aeruginosa and Acinetobacter baumannii isolates. A case report study was performed at a tertiary burn care centre in Tehran, Iran. Nine isolates of Pseudomonas aeruginosa and Acinetobacter baumannii from a hospitalized case were isolated. The identity of isolates was confirmed and their antibiotic susceptibility testing was performed. Eight out of nine Pseudomonas aeruginosa and Acinetobacter baumannii isolates were resistant to Imipenem. Three out of 8 imipenem resistant isolates were also positive for KPC test. Findings of this study highlight the importance of implementation of an effective infection control strategy in order to prevent and reduce the emergence and spread of gram negative Carbapenemase-producing organisms in Iran.

  20. High genetic diversity among Pseudomonas aeruginosa and Acinetobacter spp. isolated in a public hospital in Brazil

    Vera Lúcia Dias Siqueira

    2013-03-01

    Full Text Available In Brazil and other regions of the world, Pseudomonas aeruginosa and Acinetobacter spp. have emerged as important agents of nosocomial infection and are commonly involved in outbreaks. The main objective of the present study was to evaluate the genetic relationship among P. aeruginosa and Acinetobacter spp. isolated from patients in a public university hospital in northwestern Paraná, Brazil, and report their antimicrobial resistance profile. A total of 75 P. aeruginosa and 94 Acinetobacter spp. isolates were phenotypically identified and tested for antibiotic susceptibility using automated methodology. Polymyxin B was tested by disk diffusion for P. aeruginosa. Metallo-β-lactamase (MBL was detected using a disk approximation test. Genotyping was performed using enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR. Approximately 55% of the P. aeruginosa isolates and 92% of the Acinetobacter spp. isolates were multiresistant, but none were MBL-producers. ERIC-PCR revealed the presence of small clusters of carbapenem-resistant Acinetobacter spp., most likely OXA-type carbapenemase producers. Furthermore, high genetic diversity in P. aeruginosa and Acinetobacter spp. clinical isolates was observed, suggesting that cross-transmission is not very frequent in the studied hospital.No Brasil, bem como em outras regiões do mundo, Pseudomonas aeruginosa e Acinetobacter spp. surgiram como importantes agentes de infecção nosocomial e são comumente envolvidos em surtos. O objetivo principal deste estudo foi descrever a relação genética de P. aeruginosa e Acinetobacter spp. isoladas de pacientes internados em hospital universitário público do noroeste do Paraná - Brasil e reportar o perfil de resistência dessas bactérias. Um total de 75 P. aeruginosa e 94 Acinetobacter spp. isolados foi fenotipicamente identificado e testado para a suscetibilidade aos antibióticos por metodologia automatizada. A polimixina B foi

  1. Early dissemination of OXA-72-producing Acinetobacter baumannii strain in Colombia: a case report

    Sandra Yamile Saavedra

    2014-12-01

    Full Text Available Nosocomial infections caused by carbapenem-resistant Acinetobacter baumannii isolates have reached epidemic levels in past decades. Currently this microorganism is responsible for outbreaks of difficult eradication and with high mortality rates worldwide. We herein report a rare case of an OXA-72-producing A. baumannii isolate colonizing a 47-year-old male patient with peritonitis due to abdominal stab wound, four years earlier than the first report of this carbapenemase in Acinetobacter pittii in Colombia. Although OXA-72 presents a low prevalence compared with OXA-23, our study demonstrated that A. baumannii isolates carrying the blaOXA-72 gene were present in the hospital environment in Colombia and could act as a reservoir for further spread to other Acinetobacter species, like A. pittii, causing carbapenem-resistance.

  2. CLINICAL AND ANTIMICROBIAL PROFILE OF ACINETOBACTER SPECIES AT TERTIARY CARE HOSPITAL IN CENTRAL INDIA

    Apoorva

    2014-07-01

    Full Text Available BACKGROUND: Acinetobacter are the “superbugs” of the modern hospital environment causing significant proportion of infections and in particular nosocomial infections with high mortality rates. The aim of this study was to isolate Acinetobacter species from clinical specimens and to study the antimicrobial susceptibility pattern of Acinetobacter isolates. MATERIAL AND METHODS: Two hundred and four clinical isolates of Acinetobacter species were processed for species identification by standard microbiological procedures. Antimicrobial susceptibility of these isolates was performed by Kirby-Bauer disc diffusion method. RESULTS: Out of 204 Acinetobacter isolates, 125(61.27% isolates were from ICU and 79(38.72% were from general wards. A baumannii was the most common species isolated (74.50%, followed by A.lwoffii (24.50% and A.haemolyticus (0.98%. A.baumannii showed maximum sensitivity to IPM (52.63% followed by MRP(36.18%, AK(28.28%, PIT(26.31%, TCC(21.71%, CIP(21.05% G(17.76% and COT(05.26%. Maximum resistance was observed to CTX(1.31% followed by CAZ(1.97%, CTR(1.97% and CPM(1.97% respectively. A.lwoffii showed maximum sensitivity to IPM(94% followed by AK(90%, and MRP(84%. Statistically significant difference (p value <0.001 was noticed between antibiotic resistance of A.baumannii and A.lwoffii. CONCLUSION: Continued surveillance of drug resistant strains in ICUs, combined with preventive measures remains absolutely essential to prevent or limit the spread of Acinetobacter species in hospital.

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

    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.

  4. Relationship between antimicrobial resistance and aminoglycoside-modifying enzyme gene expressions in Acinetobacter baumannii

    SHI Wei-feng; JIANG Jian-ping; MI Zu-huang

    2005-01-01

    Background Acinetobacter baumannii is one of the main gram-negative bacilli in clinical practice. Nosocomial infections caused by multi-drug resistance Acinetobacter baumannii is very difficult to treat. This study was designed to investigate the antimicrobial resistance characteristics and four resistant gene expressions of aminoglycoside-modifying enzymes including N-acetyltransferases and O-phosphotransferases in Acinetobacter baumannii. Methods Bacterial identification and antimicrobial susceptibility test were performed by PhoenixTM system in 247 strains of Acinetobacter baumannii. Minimal inhibitory concentrations (MICs) of seven aminoglycosides including gentamicin, amikacin, kanamycin, tobramycin, netilmicin, neomycin and streptomycin in 15 strains of multi-drug resistant Acinetobacter baumannii were detected by agar dilution. Four aminoglycoside-modifying enzyme genes were amplified by polymerase chain reaction (PCR) and verified by DNA sequencer.Results The resistance rates of 247 strains of Acinetobacter baumannii against cefotaxime, levofloxacin, piperacillin, aztreonam, tetracycline, ciprofloxacin and chloramphenicol were more than 50%. Imipenem and meropenem showed high antibacterial activities with resistance rates of 3.2% and 4.1%. MIC50 and MIC90 of gentamicin, amikacin, streptomycin and kanamycin in 15 strains of multi-drug resistant Acinetobacter baumanii were all more than 1024 mg/L, and the resistance rates were 100%, 100%, 100% and 93.3%, respectively. But their resistance rates to tobramycin, netilmicin and neomycin were 86.7%, 93.3% and 46.7%, respectively. Three modifying enzyme genes, including aacC1, aacC2 and aacA4 genes, were found in 15 strains, but aphA6 had not been detected. Their positive rates were 93.3%, 20.0% and 20.0%, respectively. These three genes existed simultaneously in No.19 strain. Nucleotide sequences of aacC1, aacC2 and aacA4 genes shared 100%, 97.9% and 99.7% identities with GenBank genes (AY307113, S68058 and AY

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

    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.

  6. Prognostic differences between VAP from Acinetobacter baumanii and VAP from other microorganisms.

    Di Bonito, Marianna; Caiazzo, Simona; Iannazzone, Marta; Miccichè, Viviana; De Marco, Giuseppe; De Robertis, Edoardo; Tufano, Rosalba; Piazza, Ornella

    2012-05-01

    Nosocomial infection, in particular pneumonia, is an important risk factor for hospital mortality and morbidity. Acinetobacter baumanii is a common multi-resistant microorganism responsible of Ventilator Associated Pneumonia (VAP). Currently Colistin is a rescue therapy for this pathogen. The purpose of this retrospective study is to compare the outcome of VAP caused by Acinetobacter baumanii and VAP from other microorganisms in critical patients. Comorbidity, prognostic scores, mortality and eradication frequency did not turn out significantly different between the two study groups. Colistin safety was tested. PMID:23905048

  7. Epidemiologic and Clinical Impact of Acinetobacter baumannii Colonization and Infection

    Villar, Macarena; Cano, María E.; Gato, Eva; Garnacho-Montero, José; Miguel Cisneros, José; Ruíz de Alegría, Carlos; Fernández-Cuenca, Felipe; Martínez-Martínez, Luis; Vila, Jordi; Pascual, Alvaro; Tomás, María; Bou, Germán; Rodríguez-Baño, Jesús

    2014-01-01

    Abstract Acinetobacter baumannii is one of the most important antibiotic-resistant nosocomial bacteria. We investigated changes in the clinical and molecular epidemiology of A. baumannii over a 10-year period. We compared the data from 2 prospective multicenter cohort studies in Spain, one performed in 2000 (183 patients) and one in 2010 (246 patients), which included consecutive patients infected or colonized by A. baumannii. Molecular typing was performed by repetitive extragenic palindromic polymerase chain reaction (REP-PCR), pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). The incidence density of A. baumannii colonization or infection increased significantly from 0.14 in 2000 to 0.52 in 2010 in medical services (p < 0.001). The number of non-nosocomial health care-associated cases increased from 1.2% to 14.2%, respectively (p < 0.001). Previous exposure to carbapenems increased in 2010 (16.9% in 2000 vs 27.3% in 2010, p = 0.03). The drugs most frequently used for definitive treatment of patients with infections were carbapenems in 2000 (45%) and colistin in 2010 (50.3%). There was molecular-typing evidence of an increase in the frequency of A. baumannii acquisition in non-intensive care unit wards in 2010 (7.6% in 2000 vs 19.2% in 2010, p = 0.01). By MSLT, the ST2 clonal group predominated and increased in 2010. This epidemic clonal group was more frequently resistant to imipenem and was associated with an increased risk of sepsis, although not with severe sepsis or mortality. Some significant changes were noted in the epidemiology of A. baumannii, which is increasingly affecting patients admitted to conventional wards and is also the cause of non-nosocomial health care-associated infections. Epidemic clones seem to combine antimicrobial resistance and the ability to spread, while maintaining their clinical virulence. PMID:25181313

  8. Species distribution and physiological characterization of Acinetobacter genospecies from healthy human skin of tribal population in India

    Yavankar S

    2007-01-01

    Full Text Available Background: Various reports on distribution of Acinetobacter spp. from healthy human skin restricted to urban population. However, no such data is available from healthy human skin of tribal population not exposed to modern antibiotics during their life time. Purpose: Isolation, biotyping, distribution and physiological characterisation of Acinetobacter spp. from healthy human skin of tribal population. Methods: Tribal population of Toranmal area of Satpuda Ranges, Maharashtra, India were sampled for ten body sites. Tentative Acinetobacter isolates were confirmed to the genus level by chromosomal DNA transformation assay and to species level using Bouvet and Grimont system. Novel physiological characteristics like pH, temperature and salt tolerance were studied. All strains were screened for production of various enzymes. Results: One hundred and eighteen strains were isolated, which belonged to nine Acinetobacter genospecies. A. haemolyticus was most abundant followed by A. calcoaceticus and A. genospecies 1-3. Higher percentage of Acinetobacter was recovered from skin of nose, Pawara tribe and female volunteers. They showed wide variation in temperature, salt and pH tolerance. Most of the strains could produce enzymes viz, lipase, esterase, urease and amylase. Conclusions: Acinetobacter spp. belonging to nine genospecies were obtained in the present study. Physiological characteristics including high salt, temperature and acidic pH tolerance were helpful to differentiate between the commensal and pathogenic species of Acinetobacter genus.

  9. Colistin Methanesulfonate against Multidrug-Resistant Acinetobacter baumannii in an In Vitro Pharmacodynamic Model▿

    Kroeger, Lisa A.; Hovde, Laurie B.; Mitropoulos, Isaac F.; Schafer, Jeremy; Rotschafer, John C.

    2007-01-01

    Using an in vitro pharmacodynamic model, a multidrug-resistant strain of Acinetobacter baumannii was exposed to colistin methanesulfonate alone and in combination with ceftazidime. Pre- and postexposure colistin sulfate MICs were determined. A single daily dose of colistin methanesulfonate combined with continuous-infusion ceftazidime prevented regrowth and postexposure MIC increases.

  10. Whole-Genome Sequencing Elucidates Epidemiology of Nosocomial Clusters of Acinetobacter baumannii.

    Willems, Stefanie; Kampmeier, Stefanie; Bletz, Stefan; Kossow, Annelene; Köck, Robin; Kipp, Frank; Mellmann, Alexander

    2016-09-01

    We characterized two epidemiologically similar Acinetobacter baumannii clusters from two separate intensive care units (ICU) using core genome multilocus sequence typing. Clonal spread was confirmed in ICU-1 (12 of 14 isolates shared genotypes); in ICU-2, all genotypes (13 isolates) were diverse, thus excluding transmissions and enabling adequate infection control measures. PMID:27358465

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

    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.

  12. PHENOTYPIC DETECTION OF CARBAPENEM RESISTANCE IN CLINICAL ISOLATES OF ACINETOBACTER BAUMANII IN KANCHIPURAM

    Sivasankari S

    2014-03-01

    Full Text Available Acinctobacter species are common non fermentative gram negative bacilli isolated in clinical laboratory most frequently encountered species. Acinetobacter resistance is develop due to acquired resistance. Because of frequent multidrug resistance isolates carbapenems have become important for treating resistant strains. There is a need for rapid screening & detection of MBL in Acinetobacter to modify the treatment. The present study was aim to determine the resistance of A.baumanii complese to various classes of drugs and to carbapenems and MBL production. Samples such as urine, blood, sputum, pus & body fluids. All samples were processed as per CLSI guidelines. Meropenem resistant strains were screened for carbapenemase and MBL production. Out of 92 Acinetobacter 85 (92.39% were Acinetobacter baumanii. More than 80% resistance is seen in 3rd generation Cephalosporins. Out of 21 meropenem resistant strains 14 were carbapenemase positive and 3 were MBL producers. Our study shows raising trend of multidrug resistance and carbapenem. This will help in early detection and better treatment modalities.

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

    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.

  14. Molecular epidemiology of Acinetobacter baumannii in central intensive care unit in Kosova Teaching Hospital.

    Raka, Lul; Kalenć, Smilja; Bosnjak, Zrinka; Budimir, Ana; Katić, Stjepan; Sijak, Dubravko; Mulliqi-Osmani, Gjyle; Zoutman, Dick; Jaka, Arbëresha

    2009-12-01

    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 Acinetobacter baumannii 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. PMID:20464330

  15. Molecular Epidemiology of Aminoglycosides Resistance in Acinetobacter Spp. with Emergence of Multidrug-Resistant Strains

    MH Nazem Shirazi

    2010-06-01

    Full Text Available Background: Acinetobacter spp. is characterized as an important nosocomial pathogen and increasing antimicrobial resistance. Our aim was to evaluate antimicrobial susceptibility and aminoglycosides resistance genes of Acinetobacter spp. isolated from hospitalized patients.Methods: Sixty isolates were identified as Acinetobacter species. The isolates were tested for antibiotic resistance by disc diffusion method for 12 antimicrobials. The presence of aphA6, aacC1 aadA1, and aadB genes were detected using PCR.Results: From the isolated Acinetobacter spp. the highest resistance rate showed against amikacin, tobramycin, and ceftazidim, respectively; while isolated bacteria were more sensitive to ampicillic/subactam. More than 66% of the isolates were resistant to at least three classes of antibiotics, and 27.5% of MDR strains were resistant to all seven tested classes of antimicrobials. The higher MDR rate presented in bacteria isolated from the ICU and blood samples. More than 60% of the MDR bacteria were resistance to amikacin, ceftazidim, ciprofloxacin, piperacillin/tazobactam, doxycycline, tobramycin and levofloxacin. Also, more than 60% of the isolates contained phosphotransferase aphA6, and acetyltransferase genes aacC1, but adenylyltransferase genes aadA1 (41.7%, and aadB (3.3% were less prominent. 21.7% of the strains contain three aminoglycoside resistance genes (aphA6, aacC1 and aadA1.Conclusion: The rising trend of resistance to aminoglycosides poses an alarming threat to treatment of such infections. The findings showed that clinical isolates of Acinetobacter spp. in our hospital carrying various kinds of aminoglycoside resistance genes.

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

    Li Jian; Zhu De-mei; Huang Jun; Liu Xiao-fang; Liang Wang; Zhang Jing

    2011-01-01

    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. ...

  17. Colistin and tigecycline for management of external ventricular device-related ventriculitis due to multidrug-resistant Acinetobacter baumannii

    Shrestha, Gentle Sunder; Tamang, Sushil; Paneru, Hem Raj; Shrestha, Pramesh Sunder; Keyal, Niraj; Acharya, Subhash Prasad; Marhatta, Moda Nath; Shilpakar, Sushil

    2016-01-01

    Acinetobacter baumannii is an important cause of nosocomial ventriculitis associated with external ventricular device (EVD). It is frequently multidrug resistant (MDR), carries a poor outcome, and is difficult to treat. We report a case of MDR Acinetobacter ventriculitis treated with intravenous and intraventricular colistin together with intravenous tigecycline. The patient developed nephrotoxicity and poor neurological outcome despite microbiological cure. Careful implementation of bundle of measures to minimize EVD-associated ventriculitis is valuable. PMID:27365967

  18. Assessment of Biofilm Formation and Resistance to Imipenem and Ciprofloxacin among Clinical Isolates of Acinetobacter baumannii in Tehran

    Abdi-Ali, Ahya; Hendiani, Saghar; Mohammadi, Parisa; Gharavi, Sara

    2014-01-01

    Background: Biofilms are communities of bacteria attached to the surfaces in an extracellular polymeric matrix which are associated with many chronic infections in humans. Acinetobacter spp. are emerging as a major cause of nosocomial infections and Acinetobacter baumannii is the predominant species associated with this kind of infections. Objectives: In the present study, the potential of biofilm formation of clinical isolates, A. baumannii, was assessed by using crystal violet method. Furth...

  19. Homologs of the Acinetobacter baumannii AceI Transporter Represent a New Family of Bacterial Multidrug Efflux Systems

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

    2015-01-01

    ABSTRACT 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 ch...

  20. Control of an Outbreak of Acinetobacter baumannii in Burn Unit in a Tertiary Care Hospital of North India

    Shweta Sharma; Nirmaljit Kaur; Shalini Malhotra; Preeti Madan; Charoo Hans

    2014-01-01

    Acinetobacter infection is increasing in hospitals and now it is considered as a global threat, as it can be easily transmitted and remain viable in the hospital environment for a long time due to its multidrug-resistant status, resistance to desiccation, and tendency to adhere to inanimate surfaces. Outbreaks caused by multidrug-resistant Acinetobacter baumannii (MDRAB) are difficult to control and have substantial morbidity and mortality, especially in vulnerable host. Here we are describin...

  1. Sensitive, resistant and multi-drug resistant Acinetobacter baumanii at Saudi Arabia hospital eastern region.

    Ahmed, Mughis Uddin; Farooq, Reshma; Al-Hawashim, Nadia; Ahmed, Motasim; Yiannakou, Nearchos; Sayeed, Fatima; Sayed, Ali Rifat; Lutfullah, Sualiha

    2015-05-01

    Since the Physicians start use of antibiotics long ago with un-notice drug resistance. However actual problem was recognized about 85 years ago. Antibiotic resistant and Multi-drug resistant bacterial strains are at rise throughout the world. It is physicians and researchers to take scientific research based appropriate action to overcome this ever-spreading problem. This study is designed to find out sensitive (S), resistant (R) and multi-drug resistant (MDR) Acinetobacter baumanii strain along with other isolates in the resident patients of Eastern Region of Saudi Arabia. Pseudomonas aeruginosa is excluded from other gram-negative organisms isolated from different sites as it will be dealt separately. This study is based in was retrospective observations designed to collect data of different stains of Acinetobacter baumanii with reference to their Sensitivity (S), Resistance (R), Multi-Drug Resistance (MDR) along with other Gram negative isolated from different sites (from 1st January 2004 to 31st December 2011) at King Abdulaziz Hospital located Eastern Region of Kingdom of Saudi Arabia (KSA). All necessary techniques were used to culture and perform sensitivity of these isolates. There were 4532 isolates out of which 3018 (67%) were from patients. Out of Acinetobacter baumanii infected were 906 (20%) while other 3626 (80%) isolates were miscellaneous. Numbers of patients or cases were 480 (53%) out of 906 isolates and numbers of patients or cases in other organisms were 2538 (70%) out of 3626 isolates. Acinetobacter baumanii infected patients 221 (46%) were male and 259 (54%) were female and the male and female ratio of 1:1.2. In other organisms this male female ratio was almost same. There was steady rise in number of patients and the hence the isolates from 2004 to 2011. Majority of the bacterial strains were isolated as single organism but some were isolated as double or triple or quadruple or more organisms from different sites. Sensitive, Resistant and

  2. Characterization of a Pseudomonas putida rough variant evolved in a mixed species biofilm with Acinetobacter sp. strain C6

    Hansen, Susse Kirkelund; Haagensen, Janus Anders Juul; Gjermansen, Morten; Jørgensen, Thomas Martini; Tolker-Nielsen, Tim; Molin, Søren

    2007-01-01

    shown to evolve rapidly by natural selection of better-adapted variants in a mixed-species biofilm consortium (S. K. Hansen, P. B. Rainey, J. A. Haagensen, and S. Molin, Nature 445:533-536, 2007). Adaptation was caused by mutations in a wapH homolog (PP4943) involved in core lipopolysaccharide...

  3. Effect of Acinetobacter sp on Metalaxyl Degradation and Metabolite Profile of Potato Seedlings (Solanum tuberosum L.) Alpha Variety

    Zuno-Floriano, Fabiola G.; Miller, Marion G.; Aldana-Madrid, Maria L.; Hengel, Matt J.; Gaikwad, Nilesh W.; Vladimir Tolstikov; Ana G Contreras-Cortés

    2012-01-01

    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 eff...

  4. Bacteremia due to Acinetobacter ursingii in infants: Reports of two cases

    Yakut, Nurhayat; Kepenekli, Eda Kadayifci; Karaaslan, Ayse; Atici, Serkan; Akkoc, Gulsen; Demir, Sevliya Ocal; Soysal, Ahmet; Bakir, Mustafa

    2016-01-01

    Acinetobacter ursingii is an aerobic, gram-negative, opportunistic microorganism which is rarely isolated among Acinetobacter species. We present two immunocompetent infants who developed bacteremia due to A. ursingii. The first patient is a two -month- old boy who had been hospitalized in pediatric surgery unit for suspected tracheo-esophageal fistula because of recurrent aspiration pneumonia unresponsive to antibiotic therapy. The second patient is a fourteen -month- old boy with prolonged vomiting and diarrhea. A. ursingii was isolated from their blood cultures. They were successfully treated with ampicillin-sulbactam. Although A. ursingii has recently been isolated from a clinical specimen; reports of infection with A. ursingii in children are rare. A. ursingii should be kept in mind as an opportunistic microorganism in children. PMID:27347282

  5. Detection of Multi-drug Resistant Acinetobacter Lwoffii Isolated from Soil of Mink Farm.

    Sun, Na; Wen, Yong Jun; Zhang, Shu Qin; Zhu, Hong Wei; Guo, Li; Wang, Feng Xue; Chen, Qiang; Ma, Hong Xia; Cheng, Shi Peng

    2016-07-01

    There were 4 Acinetobacter lwoffii obtained from soil samples. The antimicrobial susceptibility of the strains to 16 antimicrobial agents was investigated using K-B method. Three isolates showed the multi-drug resistance. The presence of resistance genes and integrons was determined using PCR. The aadA1, aac(3')-IIc, aph(3')-VII, aac(6')-Ib, sul2, cat2, floR, and tet(K) genes were detected, respectively. Three class 1 integrons were obtained. The arr-3-aacA4 and blaPSE-1 gene cassette, which cause resistance to aminoglycoside and beta-lactamase antibiotics. Our results reported the detection of multi-drug resistant and carried resistant genes Acinetobacter lwoffii from soil. The findings suggested that we should pay close attention to the prevalence of multi-drug resistant bacterial species of environment. PMID:27554122

  6. Isolation and Characterization of Antimicrobial Compounds in Plant Extracts against Multidrug-Resistant Acinetobacter baumannii

    Yoko Miyasaki; John D Rabenstein; Joshua Rhea; Marie-Laure Crouch; Mocek, Ulla M.; Patricia Emmett Kittell; Morgan, Margie A.; Wesley Stephen Nichols; M M Van Benschoten; William David Hardy; Liu, George Y

    2013-01-01

    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 antimicrob...

  7. Role of Thin Fimbriae in Adherence and Growth of Acinetobacter calcoaceticus RAG-1 on Hexadecane

    Rosenberg, Mel; Bayer, Edward A; Delarea, Jacob; Rosenberg, Eugene

    1982-01-01

    Acinetobacter calcoaceticus RAG-1, a hydrocarbon-degrading bacterium which adheres avidly to hydrocarbons and other hydrophobic surfaces, possesses numerous thin fimbriae (ca. 3.5-nm diameter) on the cell surface. MR-481, a nonadherent mutant of RAG-1 which is unable to grow on hexadecane under conditions of limited emulsification and low initial cell density, lacks these fimbriae. Prolonged incubation of MR-481 in hexadecane medium enriched for partial adherence revertants. The reappearance ...

  8. Role of adherence in growth of Acinetobacter calcoaceticus RAG-1 on hexadecane.

    Rosenberg, M; Rosenberg, E.

    1981-01-01

    The high affinity of Acinetobacter calcoaceticus RAG-1 for liquid hydrocarbons permitted the isolation of a spontaneous nonadherent mutant, MR-481. Strain MR-481 exhibited no significant affinity for three test hydrocarbons, yet resembled the wild type in many properties, including production of the extracellular emulsifying agent emulsan. To study the role of adherence in growth on hydrocarbons, RAG-1 and MR-481 were compared for growth on hexadecane under conditions of limited agitation and...

  9. Adherence of Acinetobacter calcoaceticus RAG-1 to human epithelial cells and to hexadecane.

    Rosenberg, M; Perry, A; Bayer, E A; Gutnick, D. L.; Rosenberg, E.; Ofek, I.

    1981-01-01

    The ability of Acinetobacter calcoaceticus RAG-1 to adhere to human epithelial cells was investigated and compared with its ability to adhere to a test hydrocarbon (hexadecane). RAG-1, a microorganism originally isolated for growth on hydrocarbon, adhered to epithelial cells when grown under conditions which promote its adherence to hexadecane; similarly, RAG-1 cells adhered poorly to epithelial cells when grown under conditions which cause the cells to possess low affinity towards hexadecane...

  10. Is inhaled colistin beneficial in ventilator associated pneumonia or nosocomial pneumonia caused by Acinetobacter baumannii?

    Demirdal, Tuna; Sari, Ummu Sena; Nemli, Salih Atakan

    2016-01-01

    Background In the present study, our objective was to evaluate and compare the clinical and microbiological results in patients receiving systemic and systemic plus inhaled colistin therapy due to nosocomial pneumonia (NP) or ventilator associated pneumonia (VAP) caused by Acinetobacter baumannii. Methods A retrospective matched case–control study was performed at the ICUs at Izmir Katip Celebi University Ataturk Training and Research Hospital from January 2013 to December 2014. Eighty patien...

  11. Inhaled Colistin for Treatment of Pneumonia due to Colistin-Only-Susceptible Acinetobacter baumannii

    Choi, Hee Kyoung; Kim, Young Keun; Kim, Hyo Youl; Uh, Young

    2013-01-01

    Purpose Colistin is used for the treatment of pneumonia associated with multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa. However, the best route of administration and dosage is not known. We report our experience with aerosolized colistin in twelve patients with pneumonia caused by colistin-only-susceptible (COS) A. baumannii. Materials and Methods We retrospectively reviewed patients' medical records who were treated with aerosolized colistin for the treatment of pneum...

  12. Clinical Use of Colistin Induces Cross-Resistance to Host Antimicrobials in Acinetobacter baumannii

    Napier, Brooke A.; Burd, Eileen M.; Satola, Sarah W.; Cagle, Stephanie M.; Ray, Susan M; McGann, Patrick; Pohl, Jan; Lesho, Emil P.; Weiss, David S.

    2013-01-01

    ABSTRACT The alarming rise in antibiotic resistance has led to an increase in patient mortality and health care costs. This problem is compounded by the absence of new antibiotics close to regulatory approval. Acinetobacter baumannii is a human pathogen that causes infections primarily in patients in intensive care units (ICUs) and is highly antibiotic resistant. Colistin is one of the last-line antibiotics for treating A. baumannii infections; however, colistin-resistant strains are becoming...

  13. Colistin against colistin-only-susceptible Acinetobacter baumannii-related infections: Monotherapy or combination therapy?

    F Simsek; Gedik, H; M T Yildirmak; N E Iris; A Türkmen; ERSOY, A.; Ersöz, M; A Gücüyener

    2012-01-01

    Purpose: To evaluate the outcomes of the patients who were infected with colistin-only-susceptible (COS) Acinetobacter baumannii and treated with either colistin monotherapy or colistin combined therapy. Materials and Methods: This retrospective case-control study was conducted in the training and research hospital with an 800 beds between August 2008 and December 2011. The patients, who were infected with COS A. baumannii and received either colistin monotherapy or colistin combined therapy,...

  14. Detection of colistin sensitivity in clinical isolates of Acinetobacter baumannii in Iran

    Bahareh Vakili; Hossein Fazeli; Parisa Shoaei; Majid Yaran; Behrooz Ataei; Farzin Khorvash; Moj Khaleghi

    2014-01-01

    Background: Nosocomial infection caused by Acinetobacter baumannii has emerged as a serious problem world-wide. Finding the suitable drug is an important priority. The aim of this study was to determine colistin (polymyxin E) resistance in clinical isolates of A. baumannii from intensive care units (ICUs) of Al Zahra Hospital. Materials and Methods: Sixty isolates of A. baumannii from patients hospitalized in ICU (Al Zahra Hospital, Isfahan University of Medical Sciences [IUMS]) were studied....

  15. Impaired Virulence and In Vivo Fitness of Colistin-Resistant Acinetobacter baumannii

    López-Rojas, Rafael; Domínguez-Herrera, Juan; McConnell, Michael J.; Docobo-Pérez, Fernando; Smani, Younes; Fernández-Reyes, María; Rivas, Luis; Pachón, Jerónimo

    2011-01-01

    Acinetobacter baumannii (American Type Culture Collection strain 19606) acquires mutations in the pmrB gene during the in vitro development of resistance to colistin. The colistin-resistant strain has lower affinity for colistin, reduced in vivo fitness (competition index, .016), and decreased virulence, both in terms of mortality (0% lethal dose, 6.9 vs 4.9 log colony-forming units) and survival in a mouse model of peritoneal sepsis. These results may explain the low incidence and disseminat...

  16. In Vitro Antimicrobial Activity and Mutant Prevention Concentration of Colistin against Acinetobacter baumannii▿

    Cai, Yun; Li, Ran; Liang, Beibei; Bai, Nan; Liu, Youning; Wang, Rui

    2010-01-01

    The antimicrobial activities of colistin and other antibiotics against clinical Acinetobacter baumannii and the mutant prevention concentration (MPC) of colistin against multidrug-resistant A. baumannii were studied. All 70 stains tested were sensitive to colistin. The MPC range of colistin against 30 multidrug-resistant A. baumannii stains was approximately 32 to >128 μg/ml, and the MPC at which 90% of the isolates tested were prevented (MPC90) exceeded 128 μg/ml, which was much higher than ...

  17. Exocellular esterase and emulsan release from the cell surface of Acinetobacter calcoaceticus.

    Shabtai, Y; Gutnick, D. L.

    1985-01-01

    An esterase activity has been found, both in the cell-free growth medium and on the cell surface of the hydrocarbon-degrading Acinetobacter calcoaceticus RAG-1. The enzyme catalyzed the hydrolysis of acetyl and other acyl groups from triglycerides and aryl and alkyl esters. Emulsan, the extracellular heteropolysaccharide bioemulsifier produced by strain RAG-1, was also a substrate for the enzyme. Gel filtration showed that the cell-free enzyme was released from the cell surface either emulsan...

  18. Multidrug-resistant Acinetobacter lwoffii infection in neonatal intensive care units

    Nakwan, Narongsak

    2011-01-01

    Narongsak Nakwan1,2, Jeerawan Wannaro2, Narongwit Nakwan31Neonatal Intensive Care Unit, 2Department of Pediatrics, 3Department of Medicine, Hat Yai Medical Education Center, Hat Yai Hospital, Songkhla, ThailandAim: To describe the clinical, bacteriological features, and outcome of Acinetobacter lwoffii infection in the neonatal population.Method: We retrospectively reviewed the medical records of four neonatal cases of A. lwoffii infection admitted to the Hat Yai Hospital, January 2005 to Dec...

  19. Genes Involved in the Biosynthesis and Transport of Acinetobactin in Acinetobacter baumannii

    Hasan, Tarik; Choi, Chul Hee; Oh, Man Hwan

    2015-01-01

    Pathogenic bacteria survive in iron-limited host environments by using several iron acquisition mechanisms. Acinetobacter baumannii, causing serious infections in compromised patients, produces an iron-chelating molecule, called acinetobactin, which is composed of equimolar quantities of 2,3-dihydroxybenzoic acid (DHBA), L-threonine, and N-hydroxyhistamine, to compete with host cells for iron. Genes that are involved in the production and transport of acinetobactin are clustered within the ge...

  20. Simple Method for Markerless Gene Deletion in Multidrug-Resistant Acinetobacter baumannii

    Oh, Man Hwan; Lee, Je Chul; Kim, Jungmin; Choi, Chul Hee; Han, Kyudong

    2015-01-01

    The traditional markerless gene deletion technique based on overlap extension PCR has been used for generating gene deletions in multidrug-resistant Acinetobacter baumannii. However, the method is time-consuming because it requires restriction digestion of the PCR products in DNA cloning and the construction of new vectors containing a suitable antibiotic resistance cassette for the selection of A. baumannii merodiploids. Moreover, the availability of restriction sites and the selection of re...

  1. Wide Distribution of Carbapenem Resistant Acinetobacter baumannii in Burns Patients in Iran

    zahra eFarshadzadeh; Farhad Bonakdar Hashemi; Sara eRahimi; Babak ePourakbari; Davoud eEsmaeili; Mohammad Ali Haghighi; Ali eMajidpour; Saeed eShojaa; Maryam eRahmani; Samira eGharesi; Masoud eAziemzadeh; Abbas eBahador

    2015-01-01

    Antimicrobial resistance in carbapenem non-susceptible Acinetobacter baumannii (CNSAb) is a major public health concern globally. This study determined the antibiotic resistance and molecular epidemiology of CNSAb isolates from a referral burn center in Tehran, Iran.Sixty-nine CNSAb isolates were tested for susceptibility to antimicrobial agents using the E-test methodology. Multiple locus variable number tandem repeat analysis (MLVA), Multilocus sequence typing and multiplex PCR were perform...

  2. Wide distribution of carbapenem resistant Acinetobacter baumannii in burns patients in Iran

    Farshadzadeh, Zahra; Farhad B. Hashemi; Rahimi, Sara; Pourakbari, Babak; Esmaeili, Davoud; Haghighi, Mohammad A.; Majidpour, Ali; Shojaa, Saeed; Rahmani, Maryam; Gharesi, Samira; Aziemzadeh, Masoud; BAHADOR, Abbas

    2015-01-01

    Antimicrobial resistance in carbapenem non-susceptible Acinetobacter baumannii (CNSAb) is a major public health concern globally. This study determined the antibiotic resistance and molecular epidemiology of CNSAb isolates from a referral burn center in Tehran, Iran. Sixty-nine CNSAb isolates were tested for susceptibility to antimicrobial agents using the E test methodology. Multiple locus variable number tandem repeat analysis (MLVA), Multilocus sequence typing (MLST) and multiplex PCR were...

  3. Predictors of Multidrug Resistant Acinetobacter Baumannii Infections in Surgical Intensive Care Patients: A Retrospective Analysis

    Aynur Camkıran; Aycan Kundakcı; Coşkun Araz; Arash Pirat; Pınar Zeyneloğlu; Hande Arslan; Gülnaz Arslan

    2011-01-01

    Objective: Multidrug resistant Acinetobacter baumannii (MRAB) is an important cause of hospital acquired infection and leads to an increasing morbidity and mortality in intensive care units (ICU). The aim of this study was to investigate the predictors of MRAB infection in surgical ICU patients. Material and Method: The charts of the patients who were admitted to the ICU between January 2008 and August 2010 were reviewed to identify patients with MRAB infection. Recorded data were as fo...

  4. An Update on the arsenal for multidrug-resistant Acinetobacter infections: Polymyxin antibiotics

    Zahra Kassamali; Rupali Jain; Danziger, Larry H.

    2015-01-01

    Objective: 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. Methods: A literature search was performed using the search terms Acinetobacter, polymyxin, colistin, polymyxin B on MEDLINE. Additional references were identified from the resulting citations. Results: Increasing the dose of polymyxin B or colistin and using either in combination with other antibiotic age...

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

    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.

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

    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 ostatní: 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

  7. Effects of Psychrotrophic Bacteria, Serratia liquefaciens and Acinetobacter genomospecies 10 on Yogurt Quality

    Shin, Yong Kook; Oh, Nam Su; Lee, Hyun Ah; Choi, Jong-Woo; Nam, Myoung Soo

    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 ea...

  8. Epidemiology of Carbapenemase-Producing Enterobacteriaceae and Acinetobacter baumannii in Mediterranean Countries

    Nassima Djahmi; Catherine Dunyach-Remy; Alix Pantel; Mazouz Dekhil; Albert Sotto; Jean-Philippe Lavigne

    2014-01-01

    The emergence and global spread of carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii are of great concern to health services worldwide. These β -lactamases hydrolyse almost all β -lactams, are plasmid-encoded, and are easily transferable among bacterial species. They are mostly of the KPC, VIM, IMP, NDM, and OXA-48 types. Their current extensive spread worldwide in Enterobacteriaceae is an important source of concern. Infections caused by these bacteria have limited treat...

  9. Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal

    Goel, Vikas Kumar; Kapil, Arti

    2001-01-01

    Background Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. Results/ Discussion Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses ...

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

    Keramettin Yanik

    2015-01-01

    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 investiga...

  11. Prote??mica de expresi??n diferencial en Acinetobacter baumanii resistente a colistina

    Rodr??guez Falc??n, Manuel

    2010-01-01

    Normally present in water, soil and waste water, Acinetobacter baumannii has become animportant nosocomial pathogen, as causal agent of pneumonias, septicemias and urinarytract infections, among other complications in compromised patients from hospital???sintensive care units. One of its last acquired abilities is the resistance to colistin (polymixinE), the last therapeutic option for its infections. In this thesis, descriptive and quantitativedifferential expression proteomics is used in th...

  12. Seasonal Variation of Endemic Strains of Acinetobacter Baumanii Izolated from Intubated Surgical ICU patients

    Jovanovska-Popovska, Katja; Zdravkovska, Milka; Petrovska, Milena; Stojkovska, Vesna; Osmani, Dugagjin; Memeti, Shaban; Petrovska, Branka

    2013-01-01

    This study was performed at the Clinic for anestesiology, reanimation and intensive care - KARIL, Skopje, Republic of Macedonia. Bacteriological data for cannulas and tubes from 01.01.2010 to 31.12.2012 were retrieved from the microbiology laboratory database and reviewed. Acinetobacter baumannii isolates were presumptively identified by using morphology of the colonies, Gram staining, oxydase and catalase reactions. Then were performed standard IMViC biochemical series (indol, methyl rot...

  13. Proteómica de expresión diferencial en Acinetobacter baumanii resistente a colistina

    Rodríguez Falcón, Manuel

    2010-01-01

    Normally present in water, soil and waste water, Acinetobacter baumannii has become an important nosocomial pathogen, as causal agent of pneumonias, septicemias and urinary tract infections, among other complications in compromised patients from hospital’s intensive care units. One of its last acquired abilities is the resistance to colistin (polymixin E), the last therapeutic option for its infections. In this thesis, descriptive and quantitative differential expression proteo...

  14. STRUCTURES OF THE CLASS D CARBAPENEMASE OXA-24 FROM ACINETOBACTER BAUMANNII IN COMPLEX WITH DORIPENEM

    Schneider, Kyle D.; Ortega, Caleb J.; Renck, Nicholas A.; Robert A Bonomo; Powers, Rachel A.; Leonard, David A.

    2011-01-01

    The emergence of class D β-lactamases with carbapenemase activity presents an enormous challenge to health practitioners, particularly with regard to the treatment of infections caused by Gram negative pathogens such as Acinetobacter baumanii. Unfortunately, class D β-lactamases with carbapenemase activity are resistant to β-lactamase inhibitors. To better understand the details of the how these enzymes bind and hydrolyze carbapenems, we have determined the structures of two deacylation-defic...

  15. Development of antimicrobial resistance in acinetobacter spp and methicillin-resistant staphylococcus aureus

    Davies, Sarah Elisabeth

    2009-01-01

    Background: Acinetobacter baumannii and methicillin-resistant Staphylococcus aureus (MRSA) represent the most worrying Gram-negative and Gram-positive nosocomial pathogens of the present age. They are of increasing concern in the clinical environment due to their multi-drug resistance and the dwindling therapeutic options available. A. baumannii is the most frequently isolated clinical species of the genus, and is able to rapidly acquire resistance. Hypermutators, most frequent...

  16. Emerging broad-spectrum resistance in Pseudomonas aeruginosa and Acinetobacter baumannii: Mechanisms and epidemiology

    Potron, Anaïs; Poirel , Laurent; Nordmann, Patrice

    2015-01-01

    Multidrug resistance is quite common among non-fermenting Gram-negative rods, in particular among clinically relevant species including Pseudomonas aeruginosa and Acinetobacter baumannii. These bacterial species, which are mainly nosocomial pathogens, possess a diversity of resistance mechanisms that may lead to multidrug or even pandrug resistance. Extended-spectrum β-lactamases (ESBLs) conferring resistance to broad-spectrum cephalosporins, carbapenemases conferring resistance to carbapenem...

  17. Endogenous hydrogen peroxide increases biofilm formation by inducing exopolysaccharide production in Acinetobacter oleivorans DR1

    In-Ae Jang; Jisun Kim; Woojun Park

    2016-01-01

    In this study, we investigated differentially expressed proteins in Acinetobacter oleivorans cells during planktonic and biofilm growth by using 2-dimensional gel electrophoresis combined with matrix-assisted laser desorption time-of-flight mass spectrometry. We focused on the role of oxidative stress resistance during biofilm formation using mutants defective in alkyl hydroperoxide reductase (AhpC) because its production in aged biofilms was enhanced compared to that in planktonic cells. Res...

  18. Immunization against Multidrug-Resistant Acinetobacter baumannii Effectively Protects Mice in both Pneumonia and Sepsis Models

    Huang, Weiwei; Yao, Yufeng; Long, Qiong; Yang, Xu; Sun, Wenjia; Liu, Cunbao; Jin, Xiaomei; LI Yang; Chu, Xiaojie; Chen, Bin; Ma, Yanbing

    2014-01-01

    Objective Acinetobacter baumannii is considered the prototypical example of a multi- or pan- drug-resistant bacterium. It has been increasingly implicated as a major cause of nosocomial and community-associated infections. This study proposed to evaluate the efficacy of immunological approaches to prevent and treat A. baumannii infections. Methods Mice were immunized with outer membrane vesicles (OMVs) prepared from a clinically isolated multidrug-resistant strain of A. baumannii. Pneumonia a...

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

    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.  

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

    Lul Raka

    2009-12-01

    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.

  1. Biofilm may not be Necessary for the Epidemic Spread of Acinetobacter baumannii

    Hu, Yuan; He, Lihua; Tao, Xiaoxia; Meng, Fanliang; Zhang, Jianzhong

    2016-01-01

    Biofilm is recognized as a contributing factor to the capacity of Acinetobacter baumannii to persist and prosper in medical settings, but it is still unknown whether biofilms contribute to the spread of A. baumannii. In this study, the biofilm formation of 114 clinical A. baumannii isolates and 32 non-baumannii Acinetobacter isolates was investigated using a microtiter plate assay. The clonal relationships among A. baumannii isolates were assessed using pulsed-field gel electrophoresis and multilocus sequence typing, and one major outbreak clone and 5 other epidemic clones were identified. Compared with the epidemic or outbreak A. baumannii isolates, the sporadic isolates had significantly higher biofilm formation, but no significant difference was observed between the sporadic A. baumannii isolates and the non-baumannii Acinetobacter isolates, suggesting that biofilm is not important for the epidemic spread of A. baumannii. Of the multidrug-resistant (MDR) A. baumannii isolates in this study, 95.7% were assigned to international clone 2 (IC2) and showed significantly lower biofilm formations than the other isolates, suggesting that biofilm did not contribute to the high success of IC2. These findings have increased our understanding of the potential relationship between biofilm formation and the epidemic capacity of A. baumannii. PMID:27558010

  2. The population structure of Acinetobacter baumannii: expanding multiresistant clones from an ancestral susceptible genetic pool.

    Laure Diancourt

    Full Text Available Outbreaks of hospital infections caused by multidrug resistant Acinetobacter baumannii strains are of increasing concern worldwide. Although it has been reported that particular outbreak strains are geographically widespread, little is known about the diversity and phylogenetic relatedness of A. baumannii clonal groups. Sequencing of internal portions of seven housekeeping genes (total 2,976 nt was performed in 154 A. baumannii strains covering the breadth of known diversity and including representatives of previously recognized international clones, and in 19 representatives of other Acinetobacter species. Restricted amounts of diversity and a star-like phylogeny reveal that A. baumannii is a genetically compact species that suffered a severe bottleneck in the recent past, possibly linked to a restricted ecological niche. A. baumannii is neatly demarcated from its closest relative (genomic species 13TU and other Acinetobacter species. Multilocus sequence typing analysis demonstrated that the previously recognized international clones I to III correspond to three clonal complexes, each made of a central, predominant genotype and few single locus variants, a hallmark of recent clonal expansion. Whereas antimicrobial resistance was almost universal among isolates of these and a novel international clone (ST15, isolates of the other genotypes were mostly susceptible. This dichotomy indicates that antimicrobial resistance is a major selective advantage that drives the ongoing rapid clonal expansion of these highly problematic agents of nosocomial infections.

  3. The Population Structure of Acinetobacter baumannii: Expanding Multiresistant Clones from an Ancestral Susceptible Genetic Pool

    Diancourt, Laure; Passet, Virginie; Nemec, Alexandr; Dijkshoorn, Lenie; Brisse, Sylvain

    2010-01-01

    Outbreaks of hospital infections caused by multidrug resistant Acinetobacter baumannii strains are of increasing concern worldwide. Although it has been reported that particular outbreak strains are geographically widespread, little is known about the diversity and phylogenetic relatedness of A. baumannii clonal groups. Sequencing of internal portions of seven housekeeping genes (total 2,976 nt) was performed in 154 A. baumannii strains covering the breadth of known diversity and including representatives of previously recognized international clones, and in 19 representatives of other Acinetobacter species. Restricted amounts of diversity and a star-like phylogeny reveal that A. baumannii is a genetically compact species that suffered a severe bottleneck in the recent past, possibly linked to a restricted ecological niche. A. baumannii is neatly demarcated from its closest relative (genomic species 13TU) and other Acinetobacter species. Multilocus sequence typing analysis demonstrated that the previously recognized international clones I to III correspond to three clonal complexes, each made of a central, predominant genotype and few single locus variants, a hallmark of recent clonal expansion. Whereas antimicrobial resistance was almost universal among isolates of these and a novel international clone (ST15), isolates of the other genotypes were mostly susceptible. This dichotomy indicates that antimicrobial resistance is a major selective advantage that drives the ongoing rapid clonal expansion of these highly problematic agents of nosocomial infections. PMID:20383326

  4. Control of Branchionus sp. and Amoeba sp. in cultures of Arthrospira sp. Control de Branchionus sp. y Amoeba sp. en cultivos de Arthrospira sp.

    Carlos Méndez; Eduardo Uribe

    2012-01-01

    Cultivation of cyanobacterium Arthrospira sp. has been developed in many countries for the production of proteins, pigments and other compounds. Outdoor mass cultures are often affected by biological contamination, drastically reducing productivity as far as bringing death. This study evaluates the control of Branchionus sp. and Amoeba sp. with two chemical compounds: urea (U) and ammonium bicarbonate (AB), in laboratory conditions and outdoor mass culture of Arthrospira sp. The lethal concen...

  5. Antibiotic Sensitivity Pattern of Blood Isolates of Acinetobacter Species in a Tertiary Care Hospital: A Retrospective Analysis

    P. S. Shareek

    2012-01-01

    Full Text Available Problem statement: Multi-drug resistant Acinetobacter bacterium is one of the major causes of sepsis in ICUs in tertiary care hospitals in India. In this report we describe the antibiotic sensitivity patterns of Acinetobacter species isolated from blood over a one year period at a tertiary care hospital. Approach: We retrospectively analyzed the sensitivity pattern of Acinetobacter species isolated from blood during the period 1/6/2010 to 31/5/2011. Isolation and identification were performed using the best alert system and VITEK2 respectively. Sensitivities were determined by Kirby Bauer disc diffusion and broth dilution using VITEK2 -AST cards. Results: The total number of Acinetobacter species isolated during the study period was 72, out of which 57 (79% were A. baumanii, 7 (9.7% were A. Iwofii and 3 (5.2% were A. Junii. One each from A. calcoaceticus, A. ursingii and A. denitrificans were isolated. All of the baumanii isolates were sensitive to polymyxin B and 61.4% were sensitive to tigecycline. Only 25% of the isolates in baumanii group were sensitive to meropenem and imipenem. In the non-baumanii group however, 73% were sensitive to carbapenems. Conclusion: There is a very high incidence of resistance to most antibiotics, including carbapenems. All of the Acinetobacter isolates tested are sensitive to polymyxin B. Tigecycline is the only other drug with reasonable susceptibilities, but this drug is not recommended for primary bacteriemias. If Acinetobacter sepsis is suspected, empiric therapy with polymyxins, followed by de-escalation after sensitivity results are back, is advisable.

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

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

    2014-01-01

    disease and environmental persistence of A. baumannii. Recently, it was shown that a single biosynthetic pathway was responsible for the generation of capsule polysaccharide and O-linked protein glycosylation. Because of the requirement of these carbohydrates for virulence and the non-template driven...... heterogeneity is a widespread phenomena in Acinetobacter O-linked glycosylation. By comparing the 11 main glycoforms and over 20 alternative glycoforms characterized within the 15 strains, trends within the glycan utilized for O-linked glycosylation could be observed. These trends reveal Acinetobacter O...

  7. Detection of AmpC β-lactamases in Acinetobacter baumannii in the Xuzhou region and analysis of drug resistance

    LIU, YONGRUI; LIU, XIANGQUN

    2015-01-01

    The aim of the present study was to determine the prevalence and related drug resistance of AmpC β-lactamases in Acinetobacter baumannii in tertiary-level hospitals in the Xuzhou region in China. A total of 134 clinical isolates of non-repetitive Acinetobacter baumannii were collected from different hospitals in the Xuzhou region, and multiplex polymerase chain reaction (PCR) was employed to determine the genotype of AmpC. The PCR products were purified and sequenced. The susceptibility to an...

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

    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. PMID:25243569

  9. Association between acute motor axonal neuropathy and septic shock due to Acinetobacter baumannii.

    Toscani, Lucia; Guarducci, Diletta; Matà, Sabrina; Furlan, Tiziana; Ballo, Piercarlo

    2015-12-01

    In this report, we describe a case of acute motoral axonal neuropathy (AMAN) following septic shock due to Acinetobacter baumannii. The aetiology of AMAN is still not fully clarified. An association with a potential infection by Campylobacter jejuni, resulting in stimulation of autoimmune response against gangliosides mediated by a phenomenon of molecular mimicry, is believed to play a major role. Since the lipopolysaccharide of A. baumannii has a structure that is similar to that of C. jejuni, we hypothesise that the infection by A. baumannii in our patient may have had a pathogenic role in the development of the neurological picture via a mechanism of molecular mimicry. PMID:26700086

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

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

    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 r...

  11. Genetic Variability among ampC Genes from Acinetobacter Genomic Species 3▿

    Beceiro, Alejandro; Pérez, Astrid; Fernández-Cuenca, Felipe; Martínez-Martínez, Luis; Pascual, Alvaro; Vila, Jordi; Rodríguez-Baño, Jesús; Cisneros, Jose Miguel; Pachón, Jerónimo; Bou, Germán

    2008-01-01

    As a part of a nationwide study in Spain, 15 clinical isolates of Acinetobacter genomic species 3 (AG3) were analyzed. The main objective of the study was to characterize the ampC genes from these isolates and to determine their involvement in β-lactam resistance in AG3. The 15 AG3 isolates showed different profiles of resistance to ampicillin (range of MICs, 12 to >256 μg/ml). Nucleotide sequencing of the 15 ampC genes yielded 12 new AmpC enzymes (ADC-12 to ADC-23). The 12 AG3 enzymes showed...

  12. Eksternal ventriküler drenaj sistemiyle ilişkili Acinetobacter baumanii menenjiti

    Aktaş, Osman; Recep KEŞLİ; Yazgi, Halil

    2000-01-01

    Akut hidrosefalisinden ötürü eksternal ventriküler drenaj uygulanan bir hastada çoklu antibiyotik direnci gösteren bir Acinetobacter baumanii suşu nozokomiyal menenjite neden olmuştur. Hastanın beyin omurilik sıvısından izole edilen bakteri sadece netilmisin, imipenem, meropenem, siprofloksasin ve tikarsilin+klavulanik asite duyarlı; amikasin, ampisilin, ampisilin sülbaktam, penisilin G, sefiksim, sefoperazon, seftazidim, seftriakson ve trimetoprim-sulfametaksosole dirençli bulunmuştur, Bu ya...

  13. Caracterización de integrones de clase I en aislamientos hospitalarios de acinetobacter baumannii

    Gáfaro Montejo, Alexis

    2012-01-01

    Se analizaron 129 aislamientos de Acinetobacter baumannii obtenidos de hospitales colombianos de tercer nivel con el objetivo de detectar y caracterizar integrones de tipo I (elementos genéticos importantes por la capacidad de adquirir determinantes genéticos de resistencia a los antibióticos) y su relación con el fenotipo de resistencia antibiótica. De los aislamientos estudiados el 24% fueron positivos para la presencia del integrón de tipo I. La caracterización de estos últimos demostró...

  14. Siderophoregenic Acinetobacter calcoaceticus Isolated From Wheat Rhizosphere With Strong PGPR Activity

    Chaudhari Bhushan, L.

    2009-01-01

    Full Text Available Thirty-two bacterial isolates were obtained from wheat rhizosphere in black cotton soils of North Maharashtra region and subsequently tested for in-vitro siderophore production. Wheat isolate SCW1, being a strong siderophore producer, was selected, identified and confirmed as Acinetobacter calcoaceticus. The strain produced catechol type of siderophores during exponential phase which was influenced by iron content of medium. Seed bacterization with siderophoregenic A. calcoaceticus improved plant growth in pot and field studies. Such PGPR activity was attributed to the ability of strain to solubilise phosphates and produce IAA. Siderophore mediated antagonism was observed against common phytopathogens viz., Aspergillus flavus, A. niger, Colletotrichum capsicum and Fusarium oxysporum.

  15. Parasitismo por Giardia sp. e Cryptosporidium sp. em Coendou villosus Parasitism by Giardia sp. and Cryptosporidium sp. in Coendou villosus

    João Fabio Soares

    2008-04-01

    Full Text Available O objetivo deste trabalho foi verificar o possível parasitismo por Giardia sp. e Cryptosporidium sp. em amostras de fezes de ouriço-cacheiro (Coendou villosus. As amostras foram analisadas pelo método de centrífugo-flutuação com sulfato de zinco e apresentaram elevada infecção por cistos de Giardia sp. e por oocistos de Cryptosporidium sp., embora os animais não apresentassem sinal clínico decorrente disso.This research was aimed at verifing the possible parasitism by Giardia sp. and Cryptosporidium sp. in porcupine (Coendou villosus faeces samples. Samples were analyzed by the centrifugal-flotation method with zinc sulphate and showed high infection by cysts of Giardia sp. and by oocysts of Cryptosporidium sp., although the animals did not show any associated clinical sign.

  16. Comparison of denitrification between Paracoccus sp. and Diaphorobacter sp.

    Chakravarthy, Srinandan S; Pande, Samay; Kapoor, Ashish; Nerurkar, Anuradha S

    2011-09-01

    Denitrification was compared between Paracoccus sp. and Diaphorobacter sp. in this study, both of which were isolated from activated sludge of a denitrifying reactor. Denitrification of both isolates showed contrasting patterns, where Diaphorobacter sp. showed accumulation of nitrite in the medium while Paracoccus sp. showed no accumulation. The nitrate reduction rate was 1.5 times more than the nitrite reduction in Diaphorobacter sp., as analyzed by the resting state denitrification kinetics. Increasing the nitrate concentration in the medium increased the nitrite accumulation in Diaphorobacter sp., but not in Paracoccus sp., indicating a branched electron transfer during denitrification. Diaphorobacter sp. was unable to denitrify efficiently at high nitrate concentrations from 1 M, but Paracoccus sp. could denitrify even up to 2 M nitrate. Paracoccus sp. was found to be an efficient denitrifier with insignificant amounts of nitrite accumulation, and it could also denitrify high amounts of nitrate up to 2 M. Efficient denitrification without accumulation of intermediates like nitrite is desirable in the removal of high nitrates from wastewaters. Paracoccus sp. is shown to suffice this demand and could be a potential organism to remove high nitrates effectively. PMID:21509603

  17. Comparison of two methods for quantification of Acinetobacter baumannii biofilm formation

    Saghar Hendiani

    2014-01-01

    Full Text Available Introduction: ‏ Medical devices are made from a variety of materials such as polypropylene, polycarbonate, poly styrene, glass and etc. by attaching to this surfaces, Acinetobacter baumannii can form biofilms and then cause several device associated infections. Biofilms are communities of bacteria attached to the surfaces. In this study, biofilm formation ability in clinical isolates of Acinetobacter baumannii was assessed by two methods on different surfaces. Materials and methods: ‏ Biofilm formation by 75 clinical isolates of A. baumannii was evaluated on polycarbonate surface (microtiter plate and polypropylene surface (falcon by crystal violet and 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl-2H-tetrazolium-5-carboxanilide salt (XTT tetrazolium sodium salt assay methods. Falcon or tube method was carried out under static and agitation conditions. Results: ‏ Results showed the most isolates can form biofilm but higher numbers of isolates form biofilm on polypropylene surface under agitation. XTT method confirmed strong biofilm formation ability of 10 isolates. Discussion and conclusion: Each of the two assays showed an excellent applicability for the quantification of biofilms. The Crystal violet assay is cheap, easy and is usually used for the quantification of biofilms formed by microorganisms but XTT is more reliable and repeatable. Most of A. baumannii isolates have potential to form biofilm on the medical devices which may result in device-associated infections.

  18. Screening of Herbal-Based Bioactive Extract Against Carbapenem-Resistant Strain of Acinetobacter baumannii.

    Tiwari, Monalisa; Roy, Ranita; Tiwari, Vishvanath

    2016-07-01

    Acinetobacter baumannii is grouped in the ESKAPE pathogens by Infectious Disease Society of America, which is linked to high degree of morbidity, mortality, and increased costs. The high level of acquired and intrinsic resistance mechanisms of these bacteria makes it an urgent requirement to find a suitable alternative to carbapenem, a commonly prescribed drug for Acinetobacter infection. In this study, methanolic extracts of six medicinal plants were subjected to phytochemical screening and their antimicrobial activity was tested against two strains of A. baumannii (ATCC 19606, carbapenem-sensitive strain, and RS 307, carbapenem-resistant strain). Synergistic effect of the plant extracts and antibiotics was also tested. Bael or Aegle marmelos contains tannin, phenol, terpenoids, glycoside, alkaloids, coumarine, steroid, and quinones. Flowers of madar or Calotropis procera possess tannin, phenol, terpenoids, glycoside, quinone, anthraquinone, anthocyanin, coumarin, and steroid. An inhibitory growth curve was seen for both the bacterial strains when treated with A. marmelos, Curcuma longa, and leaves and flowers of C. procera. Antibiotics alone showed a small zone of inhibition, but when used with herbal extracts they exhibited larger zone of inhibition. Synergistic effect of A. marmelos and imipenem was the best against both the strains of A. baumannii. From this study, it can be concluded that extracts from A. marmelos and leaves and flowers of C. procera exhibited the most effective antibacterial activity. These herbal extracts may be used to screen the bioactive compound against the carbapenem-resistant strain of A. baumannii. PMID:26910023

  19. Biofilm formation in clinical isolates of nosocomial Acinetobacter baumannii and its relationship with multidrug resistance

    Ebrahim Babapour; Azam Haddadi; Reza Mirnejad; Seyed-Abdolhamid Angaji; Nour Amirmozafari

    2016-01-01

    Objective: To check biofilm formation by Acinetobacter baumannii (A. baumannii) clinical isolates and show their susceptibility to different antibiotics and investigate a possible link between establishment of biofilm and multidrug resistance. Methods: This study was performed on clinical samples collected from patients with nosocomial infections in three hospitals of Tehran. Samples were initially screened by culture and biochemical tests for the presence of different species of Acinetobacter. Iden-tifications were further confirmed by PCR assays. Their susceptibilities to 11 antibiotics of different classes were determined by disc diffusion method according to Clinical and Laboratory Standards Institute guidelines. The ability to produce biofilm was investigated using methods:culture on Congo red agar, microtiter plate, and test tube method. Results: From the overall clinical samples, 156 specimens were confirmed to contain A. baumannii. The bacteria were highly resistant to most antibiotics except polymyxin B. Of these isolates, 10.26% were able to produce biofilms as shown on Congo red agar. However, the percentage of bacteria with positive biofilm in test tube, standard microtiter plate, and modified microtiter plate assays were 48.72%, 66.66%, and 73.72%, respec-tively. At least 92%of the biofilm forming isolates were multidrug resistant. Conclusions: Since most of the multidrug resistant strains produce biofilm, it seems necessary to provide continuous monitoring and determination of antibiotic susceptibility of clinical A. baumannii. This would help to select the most appropriate antibiotic for treatment.

  20. A health care-associated pneumonia case due to colistin resistant Acinetobacter baumannii

    Siran Keske

    2014-09-01

    Full Text Available A 78 year old male was hospitalized in neurology clinic with a diagnosis of encephalopathy. On 13th day of imipenem treatment for ventilator-associated pneumonia (VAP, a new VAP episode was diagnosed based on physical examination, laboratory and radiological findings. Cefoperazone-sulbactam 2x2 gr/day IV was started empirically. In the 3rd day of treatment Acinetobacter baumannii was identified from endotracheal aspirate culture that was resistant to all other antibiotics including colistin except cefoperazone-sulbactam (intermediate and tigecycline (MIC: 4 mg/L, intermediate by VITEK and E-test. Tigecycline 2 x 50 mg (after loading dose of 100 mg IV, colistin IV 2 x 150 mg and colistin inhaler 2 x 75 mg were added to the cefoperazone-sulbactam 2 x 2 gr IV. Clinical findings were improved under this combination and completed to 14 days. The patient was discharged from hospital with neurological sequel after three months. This case has been presented to emphasize that colistin resistant Acinetobacter baumannii is becoming a problem for our country. J Microbiol Infect Dis 2014; 4(3: 111-113

  1. Code blue: Acinetobacter baumannii, a nosocomial pathogen with a role in the oral cavity.

    Richards, A M; Abu Kwaik, Y; Lamont, R J

    2015-02-01

    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

  2. Structure and context of Acinetobacter transposons carrying the oxa23 carbapenemase gene.

    Nigro, Steven J; Hall, Ruth M

    2016-05-01

    Theoxa23gene encoding the OXA-23 carbapenemase (and several minor variants of it) is widespread inAcinetobacter baumanniiclinical isolates and compromises treatment with carbapenem antibiotics. The gene is derived from the chromosome ofAcinetobacter radioresistenswhere it is an intrinsic gene, here designatedoxaAr InA. baumanniiand otherAcinetobacterspecies,oxa23is usually preceded by an IS, ISAba1, which supplies the strong promoter required for the gene to confer clinically relevant levels of resistance. TheoxaArgene appears to have been mobilized twice creating Tn2008and Tn2008B, both of which consist of a single ISAba1 and anA. radioresistens-derived fragment. Tn2006and Tn2009are clearly derived from Tn2008Band are each made up of Tn2008Bwith an additional segment of unknown origin and an additional ISAba1, creating a compound transposon. Tn2006, Tn2008and possibly Tn2008Bare globally disseminated, while Tn2009has as yet only been found in China. Of the four ISAba1-associated transposons, Tn2006has been most frequently observed worldwide and Tn2006in Tn6022, known as AbaR4, appears to contribute significantly to the dissemination ofoxa23 Moreover, AbaR4, Tn2006, Tn2008and Tn2009have each been found in conjugative plasmids, further facilitating their spread. PMID:26755496

  3. Risk factors and outcomes of imipenem-resistant Acinetobacter bloodstream infection in North-eastern Malaysia

    Zakuan Zainy Deris; Mohd Nazri Shafei; Azian Harun

    2011-01-01

    Objective: To determine the risk factors and outcomes of imipenem-resistant Acinetobacterbaumannii (IRAB) bloodstream infection (BSI) cases, since there is very little publication on Acinetobacter baumannii infections from Malaysia. Methods: A cross sectional study of 41 cases (73.2%) of imipenem-sensitive Acinetobacter baumanii (ISAB) and 15 cases (26.8%) of IRAB was conducted in a teaching hospital which was located at North-Eastern state of Malaysia. Results:There was no independent risk factor for IRAB BSI identified but IRAB BSI was significantly associated with longer bacteraemic days [OR 1.23 (95% CI 1.01, 1.50)]. Although prior use of carbepenems and cephalosporin were higher among IRAB than ISAB group, statistically they were not significant. There was no significant difference in term of outcomes between the two groups. Conclusions: Although statistically not significant, this analysis compliments previous publication highlighting the importance of appropriate empiric antibiotic usage in hospital especially carbepenems and need further evaluation with bigger subjects.

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

    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.

  5. Characterisation of pellicles formed by Acinetobacter baumannii at the air-liquid interface.

    Yassine Nait Chabane

    Full Text Available The clinical importance of Acinetobacter baumannii is partly due to its natural ability to survive in the hospital environment. This persistence may be explained by its capacity to form biofilms and, interestingly, A. baumannii can form pellicles at the air-liquid interface more readily than other less pathogenic Acinetobacter species. Pellicles from twenty-six strains were morphologically classified into three groups: I egg-shaped (27%; II ball-shaped (50%; and III irregular pellicles (23%. One strain representative of each group was further analysed by Brewster's Angle Microscopy to follow pellicle development, demonstrating that their formation did not require anchoring to a solid surface. Total carbohydrate analysis of the matrix showed three main components: Glucose, GlcNAc and Kdo. Dispersin B, an enzyme that hydrolyzes poly-N-acetylglucosamine (PNAG polysaccharide, inhibited A. baumannii pellicle formation, suggesting that this exopolysaccharide contributes to pellicle formation. Also associated with the pellicle matrix were three subunits of pili assembled by chaperon-usher systems: the major CsuA/B, A1S_1510 (presented 45% of identity with the main pilin F17-A from enterotoxigenic Escherichia coli pili and A1S_2091. The presence of both PNAG polysaccharide and pili systems in matrix of pellicles might contribute to the virulence of this emerging pathogen.

  6. Characterisation of pellicles formed by Acinetobacter baumannii at the air-liquid interface.

    Nait Chabane, Yassine; Marti, Sara; Rihouey, Christophe; Alexandre, Stéphane; Hardouin, Julie; Lesouhaitier, Olivier; Vila, Jordi; Kaplan, Jeffrey B; Jouenne, Thierry; Dé, Emmanuelle

    2014-01-01

    The clinical importance of Acinetobacter baumannii is partly due to its natural ability to survive in the hospital environment. This persistence may be explained by its capacity to form biofilms and, interestingly, A. baumannii can form pellicles at the air-liquid interface more readily than other less pathogenic Acinetobacter species. Pellicles from twenty-six strains were morphologically classified into three groups: I) egg-shaped (27%); II) ball-shaped (50%); and III) irregular pellicles (23%). One strain representative of each group was further analysed by Brewster's Angle Microscopy to follow pellicle development, demonstrating that their formation did not require anchoring to a solid surface. Total carbohydrate analysis of the matrix showed three main components: Glucose, GlcNAc and Kdo. Dispersin B, an enzyme that hydrolyzes poly-N-acetylglucosamine (PNAG) polysaccharide, inhibited A. baumannii pellicle formation, suggesting that this exopolysaccharide contributes to pellicle formation. Also associated with the pellicle matrix were three subunits of pili assembled by chaperon-usher systems: the major CsuA/B, A1S_1510 (presented 45% of identity with the main pilin F17-A from enterotoxigenic Escherichia coli pili) and A1S_2091. The presence of both PNAG polysaccharide and pili systems in matrix of pellicles might contribute to the virulence of this emerging pathogen. PMID:25360550

  7. Characterization and application of a novel bioemulsifier in crude oil degradation by Acinetobacter beijerinckii ZRS.

    Zhao, Yi-He; Chen, Li-Yuan; Tian, Zi-Jing; Sun, Yue; Liu, Jin-Biao; Huang, Lei

    2016-02-01

    Bioemulsifiers can be applicated in a variety of areas such as bioremediation and microbial-enhanced oil recovery. The present study was aimed at bioemulsifier production, optimization, stability studies, and applications of the bioemulsifier produced by one of these strains, Acinetobacter beijerinckii ZRS. When Acinetobacter beijerinckii ZRS is cultured with hexadecane as a carbon source, it produces a novel extracellular emulsifying agent that does not cause remarkable reductions in surface tension. In order to enhance bioemulsifier production, response surface methodology was applied to optimize the culture medium. The bioemulsifier was subjected to thin-layer chromatography, Fourier transform infrared spectroscopy (FTIR), gel filtration chromatography, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF), and nuclear magnetic resonance (NMR), which allowed for the identification of a novel polymeric bioemulsifier. The bioemulsifier retained its properties at a wide range of pH values, high temperatures and high salinities (up to 5% [w⁄v] Na(+) and 24% Ca(2+)). To deduce the role of this bioemulsifier in a coastal zone oil spill, the propagation of oil-degrading bacteria on oil-coated grains of gravel immersed in seawater was investigated in beach-simulating tanks. The bioemulsifier played a positive role in the degradation of these hydrocarbons and increasing the light crude oil degradation rate of the bacterial strain from 37.5 to 58.3% within 56 days. Therefore, this bioemulsifier shows strong potential to be used for bioremediation of oil pollution in marine environments. PMID:26576943

  8. [Candida peritonitis and sepsis due to Acinetobacter baumannii in peritoneal dialysis: an association with prognosis not always unfavourable].

    Rapisarda, Francesco; Aliotta, Roberta; Pocorobba, Barbara; Portale, Grazia; Ferrario, Silvia; Zanoli, Luca; Fatuzzo, Pasquale

    2015-01-01

    Fungal infections have a high incidence in patients receiving peritoneal dialysis. (1)
Peritoneal dialysis is often complicated by peritonitis which has only minimally mycotic etiology, but nonetheless it is associated with 15-45% mortality (8).
 The opportunistic pathogens such as Candida can cause infection in immunocompromised conditions. Even the Acinetobacter tends to infect immunocompromised individuals and it has the same risk factors for infection as Candida: immunosuppression, malignancy, HIV positivity and all the other conditions of immunosuppression, central venous catheterization, mechanical ventilation and prolonged antibiotic therapy. The sepsis by Acinetobacter predicts a negative prognosis with the mortality rate between 20 to 60% (12), especially in cases of isolation of multi-resistant germs.
 We present a case report of a CKD patient undergoing peritoneal dialysis therapy who was hospitalized for acute pancreatitis, later complicated by the development of pancreatic pseudocysts, C. albicans peritonitis with hematologic spread of the fungus, superimposed Acinetobacter baumannii sepsis and pneumonia. She has been subjected to percutaneous drainage of pseudocysts, to switch from peritoneal dialysis to hemodialysis, to various evacuative thoracentesis, and to polymicrobial therapy (meropenem, teicoplanina, tigeciclina, linezolid, colimicina, fluconazolo, etc.) that allowed the resolution of sepsis. The peculiarity of this case is represented by the numerous morbidity that the patient developed simultaneously, with the genesis of a complex clinical picture, by the combination of infections due to Candida albicans and Acinetobacter baumannii. Successful treatment strategies allowed to fight and cure a medical condition associated with a high mortality rate. PMID:26845211

  9. Identification of Tet 39, a novel class of tetracycline resistance determinant in Acinetobacter spp. of environmental and clinical origin

    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 of...

  10. Molecular Identification and Antimicrobial Resistance Profile of Acinetobacter baumannii Isolated From Nosocomial Infections of a Teaching Hospital in Isfahan, Iran

    Fazeli; Taraghian; Kamali; Poursina; Nasr Esfahani; Moghim

    2014-01-01

    Background Multidrug resistant (MDR) and extensively drug resistant (XDR) Acinetobacter baumannii are among important causes of nosocomial infections and cause therapeutic problems worldwide. The emergence of extensively drug-resistant A. baumannii (XDRAB) cause serious threats to hospital acquired infections (HAI) worldwide and further limit the treatment options. Objectives The current study aimed to identify and isolate the MDR...

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

    Weimei Ou

    Full Text Available OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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

  12. Urban riverine environment is a source of multidrug-resistant and ESBL-producing clinically important Acinetobacter spp.

    Maravić, Ana; Skočibušić, Mirjana; Fredotović, Željana; Šamanić, Ivica; Cvjetan, Svjetlana; Knezović, Mia; Puizina, Jasna

    2016-02-01

    Some Acinetobacter species have emerged as very important opportunistic pathogens in humans. We investigated Acinetobacter spp. from the polluted urban riverine environment in Croatia in regard to species affiliation, antibiotic resistance pattern, and resistance mechanisms. Considerable number of isolates produced acquired extended-spectrum β-lactamase(s) (ESBLs), CTX-M-15 solely or with TEM-116. By Southern blot hybridization, bla TEM-116 was identified on plasmids ca. 10, 3, and 1.2 kb in Acinetobacter junii, A. gandensis, and A. johnsonii. The bla TEM-116-carrying plasmid in A. gandensis was successfully transferred by conjugation to azide-resistant Escherichia coli J53. A. radioresistens isolate also carried an intrinsic carbapenemase gene bla OXA-133 with ISAba1 insertion sequence present upstream to promote its expression. Majority of ESBL-producing isolates harbored integrases intI1 and/or intI2 and the sulfamethoxazole resistance gene sul1. Almost all isolates had overexpressed resistance-nodulation-cell division (RND) efflux system, indicating that this mechanism may have contributed to multidrug resistance phenotypes. This is the first report of environmental CTX-M-15-producing Acinetobacter spp. and the first identification of CTX-M-15 in A. johnsonii, A. junii, A. calcoaceticus, A. gandensis, A. haemolyticus, and A. radioresistens worldwide. We identified, also for the first time, the environmental Acinetobacter-producing TEM ESBLs, highlighting the potential risk for human health, and the role of these bacteria in maintenance and dissemination of clinically important antibiotic resistance genes in community through riverine environments. PMID:26490931

  13. Control of Branchionus sp. and Amoeba sp. in cultures of Arthrospira sp. Control de Branchionus sp. y Amoeba sp. en cultivos de Arthrospira sp.

    Carlos Méndez

    2012-09-01

    Full Text Available Cultivation of cyanobacterium Arthrospira sp. has been developed in many countries for the production of proteins, pigments and other compounds. Outdoor mass cultures are often affected by biological contamination, drastically reducing productivity as far as bringing death. This study evaluates the control of Branchionus sp. and Amoeba sp. with two chemical compounds: urea (U and ammonium bicarbonate (AB, in laboratory conditions and outdoor mass culture of Arthrospira sp. The lethal concentration 100 (LC100 at 24 h for Branchionus sp. and Amoeba sp. determined was of 60-80 mg L-1 (U and 100-150 mg L-1 (AB. The average effective inhibition concentration for 50% of the population (IC50 in Arthrospira sp., after 72 h, was 80 mg L-1 (U and 150 mg L-1 (AB. The application of doses of 60 mg L-1 (U or 100 mg L-1 (AB in the outdoor mass culture of this contaminated microalga, completely inhibited grazing and did not affect the growth of Arthrospira sp. but rather promoted rapid recovery of algal density at levels prior to infestation. These compounds provided an economical and effective control of predators in cultures of Arthrospira sp.El cultivo de la cianobacteria Arthrospira sp. ha sido desarrollado en muchos países para la obtención de proteínas, pigmentos y otros compuestos. Cultivo que a nivel industrial se ve afectado frecuentemente por contaminación biológica, reduciendo drásticamente la productividad hasta causar la muerte. Este estudio evalúa el control de Branchionus sp. y de Amoeba sp. con dos compuestos químicos, la urea (U y bicarbonato de amonio (AB en cultivos de Arthrospira sp. La concentración letal 100 (LC100 determinada a las 24 h para Branchionus sp. y Amoeba sp. fue de 60-80 mg L-1 (U y 100-150 mg L-1 (AB. La concentración media de inhibición efectiva, después de 72 h, para el 50% de la población (IC50 en Arthrospira fue de 80 mg L-1 (U y 150 mg L-1 (AB. La aplicación de dosis de 60 mg L-1 (U ó 100 mg L-1 (AB en

  14. Activities of Polymyxin B and Cecropin A-Melittin Peptide CA(1-8)M(1-18) against a Multiresistant Strain of Acinetobacter baumannii

    Saugar, José María; Alarcón, Teresa; López-Hernández, Susana; López-Brea, Manuel; Andreu, David; Rivas, Luis

    2002-01-01

    Polymyxin B (PXB) and the cecropin A-melittin hybrid CA(1-8)M(1-18) (KWKLFKKIGIGAVLKVLTTGLPALIS-NH2) were compared for antibiotic activity on reference and multiresistant Acinetobacter baumannii strains. Significant differences for both peptides were observed on their inner membrane interaction and inhibition by environmental factors, supporting the use of CA(1-8)M(1-18) as a potential alternative to PXB against Acinetobacter.

  15. Klinik örneklerden izole edilen Acinetobacter baumannii suşlarının in-vitro duyarlılık durumları

    Savcı, Ünsal; Özveren, Gülşen; Yenişehirli, Gülgün; Yunus BULUT; Özdaş, Sibel

    2015-01-01

    Aim: Management of Acinetobacter baumannii infection is usually difficult due to increase in multi-drug resistant Acinetobacter baumannii srains and rapid development of resistance to new antimicrobial drugs. It may cause nosocomial infections such as pneumonia, ventilator-associated pneumonia, urinary tract infections, blood stream infections, meningitis especially in intensive care units. The aim of this study was to evaluate the antimicrobial susceptibilities of 170 A. baumanii strains iso...

  16. Distribution of AdeABC efflux system genes in genotypically diverse strains of clinical Acinetobacter baumannii.

    Wieczorek, Piotr; Sacha, Paweł; Czaban, Sławomir; Hauschild, Tomasz; Ojdana, Dominika; Kowalczuk, Oksana; Milewski, Robert; Poniatowski, Bogusław; Nikliński, Jacek; Tryniszewska, Elżbieta

    2013-10-01

    Acinetobacter baumannii has emerged as a highly problematic hospital-associated pathogen. Different mechanisms contribute to the formation of multidrug resistance in A. baumannii, including the AdeABC efflux system. Distribution of the structural and regulatory genes encoding the AdeABC efflux system among genetically diverse clinical A. baumannii strains was achieved by using PCR and pulsed-field gel electrophoresis techniques. The distribution of adeABRS genes is extremely high among our A. baumannii strains, except the adeC gene. We have observed a large proportion of strains presenting multidrug-resistance phenotype for several years. The efflux pump could be an important mechanism in these strains in resistance to antibiotics. PMID:23886790

  17. Postcraniofacial trauma multidrug resistant Acinetobacter Baumannii infection treated with intravenous colistin: A rare complication

    Sanjay Rastogi

    2013-01-01

    Full Text Available Nosocomial meningitis is a rare complication of combined craniofacial and neurosurgical procedures. The increase in meningitis caused by multidrug-resistant (MDR Acinetobacter baumannii has resulted in a significant reduction in available treatment options. We report a case of 52-year-old man who sustained a complex craniofacial trauma, who developed nosocomial MDR infection caused by A. baumannii in the wound. Patient was at significant risk of developing meningitis but, he was successfully treated with intravenous colistin. To conclude, patients with complex maxillofacial trauma are at high risk of MDR A. baumannii meningitis, especially in craniofacial intensive care units, and adequate infection control measures with proper institution of antibiotics, should be used to reduce the risk of this infection

  18. Molecular typing of Acinetobacter baumannii by automated repetitive-sequence-based PCR

    Giuseppe Russello

    2011-03-01

    Full Text Available Acinetobacter baumannii has been increasingly reported as a significant causative organism of various nosocomial infections. Here we describe three different outbreaks of multidrug resistant A. baumannii started in the Intensitive Care Unit and then involving other wards of San Carlo Borromeo hospital in Milan, Italy. In order to characterize the clinical strains isolates, molecular typing using semi-automated repetitive-sequence-based PCR (rep-PCR was performed.Among the sixty-one strains analyzed, three main cluster (C1, C2, C3 were detected: C1 included six indistinguishable strains, C2 five and C3 thirty. No correlation was observed between chemosensitivity and ribotyping pattern and an high rate of carbapenems resistance was founded.

  19. Colistin against colistin-only-susceptible Acinetobacter baumannii-related infections: Monotherapy or combination therapy?

    F Simsek

    2012-01-01

    Full Text Available Purpose: To evaluate the outcomes of the patients who were infected with colistin-only-susceptible (COS Acinetobacter baumannii and treated with either colistin monotherapy or colistin combined therapy. Materials and Methods: This retrospective case-control study was conducted in the training and research hospital with an 800 beds between August 2008 and December 2011. The patients, who were infected with COS A. baumannii and received either colistin monotherapy or colistin combined therapy, were included into the study. Results: In total, 51 patients fulfilling study criteria were evaluated. Colistin monotherapy was found effective as much as colistin combined therapy in terms of clinical and microbiological responses in patients with ventilator associated pneumonia (VAP and also in patients with blood stream infections. Conclusion: Although there is no randomised controlled study yet, colistin monotherapy and colistin combined therapy are likely to achieve similar treatment responses rates. Heteroresistant strains can emerge in patients who receive colistin monotherapy

  20. Biofilm Formation and Motility Depend on the Nature of the Acinetobacter baumannii Clinical Isolates.

    Vijayakumar, Saranya; Rajenderan, Sangeetha; Laishram, Shakti; Anandan, Shalini; Balaji, Veeraraghavan; Biswas, Indranil

    2016-01-01

    Acinetobacter baumannii is a nosocomial pathogen involved in various infections ranging from minor soft-tissue infections to more severe infections such as ventilator-associated pneumonia and bacteremia. The severity and the type of infections depend on the genetic and phenotypic variations of the strains. In this study, we compared the extent of biofilm formation and motility displayed by 60 multidrug-resistant A. baumannii clinical strains isolated from blood and sputum samples from patients from Southern India. Our results showed that isolates from the sputum samples formed significantly more robust biofilm compared to the blood isolates. On the other hand, we observed that the blood isolates were more motile than the sputum isolates. To the best of our knowledge, this is the first study that systematically evaluated the correlation between these two phenotypic traits and the nature of the isolates. PMID:27252939

  1. [Management of a 4MRGN Acinetobacter baumanii outbreak in a burn unit].

    Siemers, F; Fanghänel, S; Bergmann, P A; Tamouridis, G; Stuttmann, R; Stolze, B; Hofmann, G O

    2014-08-01

    Patients with 4MRGN Acinetobacter baumanii infections in a burn unit represent great challenge. The structured management with 7 involved patients in such a situation is presented. After discovering the infectious trigger a management team is established. An immediate stop for further admissions was announced and all infected room areas and medical equipment were analysed for infection foci. The infected patients were transferred to regional hospitals or a rehabiltation hospital after finishing all surgical procedures. In one case, for whom further operations were needed, a transfer to a separated area of the intermediate care unit (IMC) within the hospital was arranged. The performed analysis of infection foci indicated a bronchoscopy tower to be the infection source. The outbreak was terminated after transferring all patients, final disinfection and subsequent nebulisation with 5-6% hydrogen peroxide within 18 days. PMID:25162239

  2. Prevalence of carbapenem resistant Pseudomonas aeruginosa and Acinetobacter baumannii in high complexity hospital

    Ana Milda Karsten Baumgart

    2010-10-01

    Full Text Available Pseudomonas aeruginosa and Acinetobacter baumannii are Gram-negative bacilli that in the last decades have become prevalent agents of hospital infection due to high antimicrobial resistance developed by these microorganisms. The present study is a retrospective analysis of all positive cultures for these microorganisms in the period of January 2004 to December 2008. Resistance levels of A. baumannii and P. aeruginosa to carbapenems was high and showed a trend to increase during the period of study. In recent years the increasing incidence and resistance levels of A. baumannii and P. aeruginosa to the antimicrobials used for their treatment in the hospital setting underscores the relevance of infections caused by these bacteria. The selective pressure caused by indiscriminated use of broad-spectrum antibiotics in empirical hospital infections is probably the main reason for such an increase with the consequent impact upon patient morbidity and mortality

  3. Emerging broad-spectrum resistance in Pseudomonas aeruginosa and Acinetobacter baumannii: Mechanisms and epidemiology.

    Potron, Anaïs; Poirel, Laurent; Nordmann, Patrice

    2015-06-01

    Multidrug resistance is quite common among non-fermenting Gram-negative rods, in particular among clinically relevant species including Pseudomonas aeruginosa and Acinetobacter baumannii. These bacterial species, which are mainly nosocomial pathogens, possess a diversity of resistance mechanisms that may lead to multidrug or even pandrug resistance. Extended-spectrum β-lactamases (ESBLs) conferring resistance to broad-spectrum cephalosporins, carbapenemases conferring resistance to carbapenems, and 16S rRNA methylases conferring resistance to all clinically relevant aminoglycosides are the most important causes of concern. Concomitant resistance to fluoroquinolones, polymyxins (colistin) and tigecycline may lead to pandrug resistance. The most important mechanisms of resistance in P. aeruginosa and A. baumannii and their most recent dissemination worldwide are detailed here. PMID:25857949

  4. Clinically Relevant Growth Conditions Alter Acinetobacter baumannii Antibiotic Susceptibility and Promote Identification of Novel Antibacterial Agents.

    Jennifer M Colquhoun

    Full Text Available Biological processes that govern bacterial proliferation and survival in the host-environment(s are likely to be vastly different from those that are required for viability in nutrient-rich laboratory media. Consequently, growth-based antimicrobial screens performed in conditions modeling aspects of bacterial disease states have the potential to identify new classes of antimicrobials that would be missed by screens performed in conventional laboratory media. Accordingly, we performed screens of the Selleck library of 853 FDA approved drugs for agents that exhibit antimicrobial activity toward the Gram-negative bacterial pathogen Acinetobacter baumannii during growth in human serum, lung surfactant, and/or the organism in the biofilm state and compared those results to that of conventional laboratory medium. Results revealed that a total of 90 compounds representing 73 antibiotics and 17 agents that were developed for alternative therapeutic indications displayed antimicrobial properties toward the test strain in at least one screening condition. Of the active library antibiotics only four agents, rifampin, rifaximin, ciprofloxacin and tetracycline, exhibited antimicrobial activity toward the organism during all screening conditions, whereas the remainder were inactive in ≥ 1 condition; 56 antibiotics were inactive during serum growth, 25 and 38 were inactive toward lung surfactant grown and biofilm-associated cells, respectively, suggesting that subsets of antibiotics may outperform others in differing infection settings. Moreover, 9 antibiotics that are predominantly used for the treatment Gram-positive pathogens and 10 non-antibiotics lacked detectable antimicrobial activity toward A. baumannii grown in conventional medium but were active during ≥ 1 alternative growth condition(s. Such agents may represent promising anti-Acinetobacter agents that would have likely been overlooked by antimicrobial whole cell screening assays performed in

  5. Structural and bioinformatic characterization of an Acinetobacter baumannii type II carrier protein

    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

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

    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)

  7. Effects of silver nanoparticles in combination with antibiotics on the resistant bacteria Acinetobacter baumannii

    Wan G

    2016-08-01

    Full Text Available Guoqing Wan,1,2 Lingao Ruan,2,3 Yu Yin,2,3 Tian Yang,2,3 Mei Ge,2 Xiaodong Cheng1,4 1School of Life Science and Technology, China Pharmaceutical University, Nanjing, 2Shanghai Laiyi Center for Biopharmaceutical R&D, 3School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of China; 4Department of Integrative Biology & Pharmacology, The University of Texas Health Science Center, Houston, TX, USA Abstract: Acinetobacter baumannii resistance to carbapenem antibiotics is a serious clinical challenge. As a newly developed technology, silver nanoparticles (AgNPs show some excellent characteristics compared to older treatments, and are a candidate for combating A. baumannii infection. However, its mechanism of action remains unclear. In this study, we combined AgNPs with antibiotics to treat carbapenem-resistant A. baumannii (aba1604. Our results showed that single AgNPs completely inhibited A. baumannii growth at 2.5 µg/mL. AgNP treatment also showed synergistic effects with the antibiotics polymixin B and rifampicin, and an additive effect with tigecyline. In vivo, we found that AgNPs–antibiotic combinations led to better survival ratios in A. baumannii-infected mouse peritonitis models than that by single drug treatment. Finally, we employed different antisense RNA-targeted Escherichia coli strains to elucidate the synergistic mechanism involved in bacterial responses to AgNPs and antibiotics. Keywords: Acinetobacter baumannii, AgNPs, synergistic, antibiotic combination, anti­sense RNA 

  8. Structural and bioinformatic characterization of an Acinetobacter baumannii type II carrier protein

    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.

  9. Association of plasmid typing to biotyping and antibiotyping in the characterization of outbreaks by Acinetobacter baumannii

    Maria Cristina Bronharo Tognim

    1999-01-01

    Full Text Available During an outbreak at an University Hospital, from April to September, in 1994, sixteen strains of Acinetobacter baumannii were isolated from patients and one strain from an enteral solution. We afterwards analyzed the outbreak by means of plasmid typing, antibiotic resistance typing and biotyping. Two main plasmid profiles were identified. Twelve strains belonged to biotype 2, and five to biotype 19. Susceptibility to amikacin and to carbenicillin allowed classification of the strains into two groups. The results show that association of those three typing methods allowed the differentiation of what was at first considered as a single outbreak into two apparently unrelated outbreaks.Durante um surto ocorrido de abril a setembro de 1994 em um Hospital Universitário, dezesseis cepas de Acinetobacter baumannii foram isoladas de pacientes e uma de solução enteral. Nós posteriormente analizamos as cepas isoladas durante o surto pelos seguintes métodos de tipagem : perfil de DNA plasmidial, perfil de antibiograma e biotipagem. Dois padrões de tipagem foram identificados pela análise do perfil plasmidial. Doze cepas foram caracterizadas como sendo do biotipo 2, e cinco do biotipo 19. O padrão de sensibilidade a amicacina e a carbenicilina possibilitou a classificação das cepas em dois grupos. Os resultados demonstraram que estes três métodos de tipagem associados possibilitaram a diferenciação do que primeiramente foi considerado como um único surto, em dois surtos aparentemente não relacionados.

  10. Characterization and plasmid elimination of NDM-1-producing Acinetobacter calcoaceticus from China.

    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.

  11. 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

    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.

  12. 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

    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.

  13. Study on biological phosphorus removal process by Acinetobacter lwoffi: possibility to by-pass the anaerobic phase

    Ghigliazza, R.; Lodi, A.; Rovatti, M. [Institute of Chemical and Process Engineering ``G.B. Bonino``, University of Genoa (Italy)

    1998-03-01

    An Acinetobacter lwoffi culture has been submitted to anaerobic/aerobic conditions in a Sequencing Batch Reactor (SBR) in order to study the ability of this strain in biological phosphorus removal process. Even by feeding a pure sodium acetate substrate, no phosphorus release has been detected during anaerobiosis, while phosphorus uptake beyond metabolic needs has been recorded during the aerobic phase; the anaerobic phase seems to have no influence on the enhanced biological phosphorus removal mechanisms. Hence aerobic batch tests have been carried out in order to verify the ability of Acinetobacter lwoffi to remove phosphorus by ``luxury uptake`` and ``overplus accumulation`` without anaerobic stress. Obtained results revealed a phosphorus removal efficiency of 75-80%. (orig.) With 5 figs., 3 tabs., 18 refs.

  14. SP-100 Test Site

    Preparatory activities are well under way at Hanford to convert the 309 Containment Building and its associated service wing to a 2.5 MWt nuclear test facility for the SP-100 Ground Engineering System (GES) test. Preliminary design is complete, encompassing facility modifications, a secondary heat transport system, a large vacuum system to enclose the high temperature reactor, a test assembly cell and handling system, control and data processing systems, and safety and auxiliary systems. The design makes extensive use of existing equipment to minimize technical risk and cost. Refurbishment of this equipment is 75% complete. The facility has been cleared of obstructing equipment from its earlier reactor test. Current activities are focusing on definitive design and preparation of the Preliminary Safety Analysis Report (PSAR) aimed at procurement and construction approvals and schedules to achieve reactor criticality by January 1992. 6 refs

  15. Resistance-Nodulation-Cell Division-Type Efflux Pump Involved in Aminoglycoside Resistance in Acinetobacter baumannii Strain BM4454

    Magnet, Sophie; Courvalin, Patrice; Lambert, Thierry

    2001-01-01

    Multidrug-resistant strain Acinetobacter baumannii BM4454 was isolated from a patient with a urinary tract infection. The adeB gene, which encodes a resistance-nodulation-cell division (RND) protein, was detected in this strain by PCR with two degenerate oligodeoxynucleotides. Insertional inactivation of adeB in BM4454, which generated BM4454-1, showed that the corresponding protein was responsible for aminoglycoside resistance and was involved in the level of susceptibility to other drugs in...

  16. Intra-pleural colistin methanesulfonate therapy for pleural infection caused by carbapenem-resistant Acinetobacter baumannii: a successful case report

    Muhammad Asim Rana; Basheer Abd El Rahaman; Ahmed Fouad Mady; Mohammed Al Odat; Abdurehman Al Harthy; Omar El Sayed Ramadan; Shehzad Ahmad Mumtaz; Omrani, Ali S

    2014-01-01

    Infections caused by carbapenem-resistant, Gram-negative bacteria are an increasing clinical challenge, since the antimicrobial treatment options are often limited to colistin methanesulfonate. No data are available regarding the pharmacokinetics of colistin in pleural fluid. We report the case of a 92-year old man with ventilator-associated pneumonia and pleurisy caused by Acinetobacter baumannii and Escherichia coli, which were both multidrug-resistant. After an unsuccessful treatment with ...

  17. Preliminary Study of Colistin versus Colistin plus Fosfomycin for Treatment of Carbapenem-Resistant Acinetobacter baumannii Infections

    Sirijatuphat, Rujipas; Thamlikitkul, Visanu

    2014-01-01

    Ninety-four patients infected with carbapenem-resistant Acinetobacter baumannii were randomized to receive colistin alone or colistin plus fosfomycin for 7 to 14 days. The patients who received combination therapy had a significantly more favorable microbiological response and a trend toward more favorable clinical outcomes and lower mortality than those who received colistin alone. (This study has been registered at ClinicalTrials.gov under registration no. NCT01297894.)

  18. In Vitro Responses of Acinetobacter baumannii to Two- and Three-Drug Combinations following Exposure to Colistin and Doripenem

    Oleksiuk, Louise M.; Nguyen, M. Hong; Press, Ellen G.; Updike, Cassaundra L.; O'Hara, Jessica A.; Doi, Yohei; Clancy, Cornelius J.; Shields, Ryan K.

    2014-01-01

    We compared in vitro killing of colistin, doripenem, and sulbactam by time-kill methods against Acinetobacter baumannii isolates collected from patients before and after colistin-doripenem treatment (initial and recurrent isolates, respectively). Colistin-doripenem bactericidal activity against recurrent isolates was attenuated (mean log10 kill, −5.74 versus −2.88; P = 0.01) but was restored by adding sulbactam. Doripenem MICs rather than colistin MICs correlated with the activity of colistin...

  19. Activity of Colistin against Heteroresistant Acinetobacter baumannii and Emergence of Resistance in an In Vitro Pharmacokinetic/Pharmacodynamic Model▿

    Tan, Chun-Hong; Jian LI; Nation, Roger L

    2007-01-01

    Three clinically relevant intermittent regimens, and a continuous infusion, of colistin were simulated in an in vitro pharmacokinetic/pharmacodynamic model against two colistin-heteroresistant strains of Acinetobacter baumannii. Extensive initial killing was followed by regrowth as early as 6 h later; bacterial density in the 24- to 72-h period was within 1 log10 CFU/ml of growth control. Population analysis profiles revealed extensive emergence of resistant subpopulations regardless of the c...

  20. In Vitro Synergy of Colistin Combinations against Colistin-Resistant Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae Isolates

    Vidaillac, Céline; Benichou, Lothaire; Duval, Raphaël E.

    2012-01-01

    Colistin resistance, although uncommon, is increasingly being reported among Gram-negative clinical pathogens, and an understanding of its impact on the activity of antimicrobials is now evolving. We evaluated the potential for synergy of colistin plus trimethoprim, trimethoprim-sulfamethoxazole (1/19 ratio), or vancomycin against 12 isolates of Acinetobacter baumannii (n = 4), Pseudomonas aeruginosa (n = 4), and Klebsiella pneumoniae (n = 4). The strains included six multidrug-resistant clin...

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

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

    2013-01-01

    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...

  2. Antibacterial Effects of Origanum vulgare Essence Against Multidrug-Resistant Acinetobacter baumannii Isolated From Selected Hospitals of Tehran, Iran

    Saghi; Bahador; Khaledi; Ataee Kachoei; Amiri Dastjerdi; Esmaeili

    2015-01-01

    Background Infection due to Acinetobacter baumannii has become a significant challenge to modern healthcare systems. The rapid emergence and global dissemination of A. baumannii as a major nosocomial pathogen is remarkable and it demonstrates its successful adaptation to the 21st century hospital environment. Recent studies have discussed about essential oil of Origanum vulgare against a range of bacteria, including various species of Staphylococcus, Pseudomonas, Bacillus and Esc...

  3. Prevalence and Characterization of Integrons in Multidrug Resistant Acinetobacter baumannii in Eastern China: A Multiple-Hospital Study

    Jing Chen; Hong Li; Jinsong Yang; Rong Zhan; Aiping Chen; Yansheng Yan

    2015-01-01

    Objective: The aim of this multiple-hospital study was to investigate the prevalence of integrons in multidrug-resistant Acinetobacter baumannii (MDRAB) in Eastern China, and characterize the integron-integrase genes, so as to provide evidence for the management and appropriate antibiotic use of MDRAB infections. Methods: A total of 425 clinical isolates of A. baumannii were collected from 16 tertiary hospitals in 11 cities of four provinces (Fujian, Jiangsu, Zhejiang and Shandong) from Janua...

  4. Phenotypic and Molecular Epidemiology of Acinetobacter calcoaceticus baumannii Complex Strains Spread at Nemazee Hospital of Shiraz, Iran

    2015-01-01

    Background Acinetobacter calcoaceticus baumannii (ACB) complex are Gram-negative opportunistic bacteria with low virulence properties. Their resistance to antibiotics has become a matter of concern in hospital infections. Objectives The present study aimed to determine the prevalence and antimicrobial susceptibility of ACB isolates collected from the Nemazee hospital of Shiraz. In addition, Pulsed Field Gel Electrophoresis (PFGE) was used to determine the genetic patterns of these strains. Pa...

  5. The Potential Benefit of 5% Sulfamylon Solution in the Treatment of Acinetobacter baumannii–contaminated Traumatic War Wounds

    Kucan, John O.; Heggers, John P.

    2005-01-01

    Background: The recent report of high numbers of Acinetobacter baumannii bloodstream infections among service members injured in Iraq and Afghanistan during the period January 2002 through August 2004 has prompted an investigation into their etiology. A review of the current guidelines for open combat casualty wounds as part of this broad investigation was not mentioned in the report. Objective: The objective of this study was 2-fold: to ascertain the susceptibility of A baumannii to currentl...

  6. Dissemination of multiple carbapenem-resistant clones of Acinetobacter baumannii in the Eastern District of Saudi Arabia

    Al-Sultan, Abdulrahman A.; Evans, Benjamin A.; Aboulmagd, Elsayed; Al-Qahtani, Ahmed A; Bohol, Marie Fe F.; Al-Ahdal, Mohammed N.; Opazo, Andres F.; Amyes, Sebastian G. B.

    2015-01-01

    It has previously been shown that carbapenem-resistant Acinetobacter baumannii are frequently detected in Saudi Arabia. The present study aimed to identify the epidemiology and distribution of antibiotic resistance determinants in these bacteria. A total of 83 A. baumannii isolates were typed by pulsed-field gel electrophoresis (PFGE), and screened by PCR for carbapenemase genes and insertion sequences. Antibiotic sensitivity to imipenem, meropenem, tigecycline, and colistin were determined. ...

  7. Innate Immune Responses to Systemic Acinetobacter baumannii Infection in Mice: Neutrophils, but Not Interleukin-17, Mediate Host Resistance▿

    Breslow, Jessica M.; Meissler, Joseph J.; Hartzell, Rebecca R.; Spence, Phillip B.; Truant, Allan; Gaughan, John; Eisenstein, Toby K.

    2011-01-01

    Acinetobacter baumannii is a nosocomial pathogen with a high prevalence of multiple-drug-resistant strains, causing pneumonia and sepsis. The current studies further develop a systemic mouse model of this infection and characterize selected innate immune responses to the organism. Five clinical isolates, with various degrees of antibiotic resistance, were assessed for virulence in two mouse strains, and between male and female mice, using intraperitoneal infection. A nearly 1,000-fold differe...

  8. Emergence of Carbapenem-Resistant Acinetobacter baumannii in Nursing Homes With High Background Rates of MRSA Colonization.

    Cheng, Vincent C C; Chen, Jonathan H K; Ng, W C; Wong, Janet Y H; Chow, Denise M K; Law, T C; So, Simon Y C; Wong, Sally C Y; Chan, T C; Chan, Felix H W; Ho, P L; Yuen, K Y

    2016-08-01

    Carbapenem-resistant Acinetobacter baumannii (CRAB) with diverse multilocus sequence typing emerged among our nursing home residents (6.5%) with a high background rate of MRSA (32.2%). Rectal swabs yielded a higher rate of CRAB detection than axillary or nasal swabs. Bed-bound status, use of adult diapers, and nasogastric tube were risk factors for CRAB colonization. Infect Control Hosp Epidemiol 2016;37:983-986. PMID:27108526

  9. Colistin Therapy in a 23-Week Gestational-Age Neonate with Multidrug-Resistant Acinetobacter baumannii Pneumonia

    Mirjana Lulic-Botica

    2011-01-01

    Full Text Available Multidrug-resistant pathogens are becoming more difficult to treat with significantly increasing infection rates. The lack of new antibiotics to combat these strains has led to the resurgence of older antibiotics. This case highlights the first reported use of colistimethate sodium treatment in a 23-week gestational-age neonate with multidrug-resistant Acinetobacter baumannii pneumonia who developed acute renal failure and seizures shortly after initiation of treatment.

  10. First report of an OXA-23 carbapenemase-producing Acinetobacter baumannii clinical isolate related to Tn2006 in Spain.

    Espinal, P; Macià, M D; Roca, I; Gato, E; Ruíz, E; Fernández-Cuenca, F; Oliver, A; Rodríguez-Baño, J; Bou, G; Tomás, M; Vila, J

    2013-01-01

    A carbapenem-resistant Acinetobacter baumannii clinical isolate belonging to European clone II and sequence type 2 was recovered from a patient in the Son Espases hospital in Mallorca, Spain. Genetic analysis showed the presence of the bla(OXA-23) gene in association with the widely disseminated transposon Tn2006. This is the first reported identification of A. baumannii carrying bla(OXA-23) in Spain. PMID:23070166

  11. Intravesical colistin irrigation to treat multidrug-resistant Acinetobacter baumannii urinary tract infection: a case report

    Volkow-Fernández Patricia; Rodríguez Cecilia Franco; Cornejo-Juárez Patricia

    2012-01-01

    Abstract Introduction Acinetobacter baumannii is a Gram-negative bacteria and a significant nosocomial pathogen in hospitals. Multidrug-resistant A. baumannii have emerged as a cause of nosocomial infections in critically ill patients. This microorganism has the ability to produce biofilms on different surfaces, which could explain their ability to persist in clinical environments and their role in device-related infections. Case presentation We present the case of a 33-year-old Hispanic man ...

  12. Evaluate the frequency distribution of nonadhesive virulence factors in carbapenemase-producing Acinetobacter baumannii isolated from clinical samples in Kermanshah

    Mohajeri, Parviz; Sharbati, Saba; Farahani, Abbas; Rezaei, Zhaleh

    2016-01-01

    Background: Acinetobacter baumannii which is a Gram-negative bacterium can cause several different infections. The appearance of carbapenemase-producing A. baumannii in recent years has made the treatment process more difficult. The identification of virulence factors (VFs), such as nonadhesives in A. baumannii, helps to fight against related infections. Materials and Methods: A total of 104 samples from teaching hospitals in Kermanshah, Iran, were collected during a 24 months period (2011-20...

  13. Contribution of Efflux Pumps, Porins, and B-Lactamases to Multidrug Resistance in Clinical Isolates of Acinetobacter baumannii

    Rumbo, C.; Gato, E.; López, M.; Ruiz de Alegría, C.; Fernández-Cuenca, F.; Martínez-Martínez, L.; Vila, J.; Pachón, J.; J. M. Cisneros; Rodríguez-Baño, Jesús; A. Pascual; Bou,G.; Tomás, M.

    2013-01-01

    Weinvestigated the mechanisms of resistance to carbapenems, aminoglycosides, glycylcyclines, tetracyclines, and quinolones in 90 multiresistant clinical strains of Acinetobacter baumannii isolated from two genetically unrelated A. baumannii clones: clone PFGEROC- 1 (53 strains producing the OXA-58B-lactamase enzyme and 18 strains with the OXA-24B-lactamase) and clone PFGE-HUI-1 (19 strains susceptible to carbapenems).Weused real-time reverse transcriptase PCR to correlate antimicrobi...

  14. Safety and effectiveness of colistin compared with tobramycin for multi-drug resistant Acinetobacter baumannii infections

    Cohen Karen; van Zyl-Smit Richard; Bamford Colleen; Gounden Ronald; Maartens Gary

    2009-01-01

    Abstract Background Nosocomial infections due to multi-drug resistant Acinetobacter baumannii are often treated with colistin, but there are few data comparing its safety and efficacy with other antimicrobials. Methods A retrospective cohort study of patients treated with colistin or tobramycin for A. baumannii infections in intensive care units (ICUs) at Groote Schuur hospital. Colistin was used for A. baumannii isolates which were resistant to all other available antimicrobials. In the tobr...

  15. Association of Single Nucleotide Polymorphisms in Toll-like Receptors with Acinetobacter baumanii Infectionin a Chinese Population

    He, Lei; Maohu LIN; Fan, Wensheng; Liu, Yunxi; SUO, Jijiang; Xing, Yubin; Jia, Ning

    2016-01-01

    Background: During recent years, infection of Acinetobacter baumanii showed a rapid growth in hospitals and community. Toll-like receptors (TLRs) are the most important pattern recognition receptors, which play a critical role during recognizing invading pathogens by the natural immune system. Our objective was to determine the associations of TLRs polymorphisms with the susceptibility to A. baumanii infection in a Chinese population. Methods: We carried out a case-control study, genotyping 1...

  16. The Study of Inhibition Effects Satureja khuzestaniea Essence against Gene Expression bap Acinetobacter baumannii with Real time PCR Technique

    Abbas Bahador; Hossein Saghii; Ramezal Ataee; Davoud Esmaeili

    2015-01-01

    Background and Aim: Acinetobacter baumannii a major hospital pathogens and causes outbreaks of infections and associated to nosocomial infections, including bacteremia, pneumonia, meningitis, urinary tract infection, and wound infections. Satureja khuzestaniea province the group Nnayyan and Carvacrol and thymol are antimicrobial activity of this plant. Biofilm-related genes (bap)-specific proteins on the cell surface generate a direct role in biofilm formation and infection of the bacteria is...

  17. Prevalence of multi drug resistant Acinetobacter baumannii in the clinical samples from Tertiary Care Hospital in Islamabad, Pakistan

    Begum, Shahzeera; Hasan, Fariha; Hussain, Shagufta; Ali Shah, Aamer

    2013-01-01

    Background & Objectives: Acinetobacter baumannii can cause a wide range of infections, including bacteremia, pneumonia, urinary tract infection, peritonitis, etc. This organism is becoming resistant to a large group of antibiotics, especially β-lactam antibiotics. The reason for multi-drug resistance may be the production of extended- spectrum β-lactamses (ESBLs), carbapenemases/metallo β-lactamases or AmpC β-lactamases. The aim of the present study was to determine the prevalence of multi-dr...

  18. Decolorization of Textile Dyes and Degradation of Mono-Azo Dye Amaranth by Acinetobacter calcoaceticus NCIM 2890

    Ghodake, Gajanan; Jadhav, Umesh; Tamboli, Dhawal; Kagalkar, Anuradha; Govindwar, Sanjay

    2011-01-01

    Acinetobacter calcoaceticus NCIM 2890 (A. caloaceticus) was found to decolorize 20 different textile dyes of various classes. Decolorization of an azo dye amaranth was observed effectively (91%) at static anoxic condition, whereas agitated culture grew well but showed less decolorization (68%) within 48 h of incubation. Induction of intracellular and extracellular lignin peroxidase, intracellular laccase, dichlorophenol indophenol (DCIP) reductase and riboflavin reductase represented their in...

  19. Colistin and Fusidic Acid, a Novel Potent Synergistic Combination for Treatment of Multidrug-Resistant Acinetobacter baumannii Infections

    Phee, Lynette M.; Betts, Jonathan W.; Bharathan, Binutha; Wareham, David W.

    2015-01-01

    The spread of multidrug-resistant Acinetobacter baumannii (MDRAB) has led to the renaissance of colistin (COL), often the only agent to which MDRAB remains susceptible. Effective therapy with COL is beset with problems due to unpredictable pharmacokinetics, toxicity, and the rapid selection of resistance. Here, we describe a potent synergistic interaction when COL was combined with fusidic acid (FD) against A. baumannii. Synergy in vitro was assessed against 11 MDRAB isolates using disc diffu...

  20. [Extended spectrum beta lactamases (ESBL) production in Acinetobacter baumannii strains isolated from Chilean hospitals belonging to VIII Region].

    Pino I, Carolina; Domínguez Y, Mariana; González R, Gerardo; Bello T, Helia; Sepúlveda A, Marcela; Mella M, Sergio; Zemelman M, Claudia; Zemelman Z, Raúl

    2007-04-01

    The resistance of Acinetobacter baumannii to ss-lactam antibiotics is mainly due to the synthesis of ss-lactamases. From a clinical point of view, this bacteria and others, grouped under the acronym SPACE (S: Serratia, P: Pseudomonas, A: Acinetobacter, C: Citrobacter, E: Enterobacter) are essentially Amp-C ss-lactamases producers. There is no local information about ESBL presence in Acinetobacter. We studied ESBL production using the Ho and col. technique modified by adding cloxacillin as chromosomal ss-lactamases inhibitor. From 69 isolates, with resistance to at least one third generation cephalosporin, only 7 showed positive synergy test. Four of these amplified for TEM family gene, and one of these amplified also for the OXA family. Our study found a low ESBL production percentage, which agrees with the premise of Amp-C as the main mechanism of resistance to ss-lactam antibiotics in A. baumannii. However, the ESBL description in these bacteria emphasizes the capacity of expressing multiple resistance mechanisms. PMID:17453072

  1. Distribution and resistance of pathogens in liver transplant recipients with Acinetobacter baumannii infection

    Gao F

    2015-03-01

    Full Text Available Fei Gao,1 Qifa Ye,2,3 Qiquan Wan,2 Shan Liu,4 Jiandang Zhou51Infectious Disease Department of Henan Province People’s Hospital, Zhengzhou, 2Department of Transplant Surgery, Third Xiangya Hospital, Central South University, Changsha, 3Department of Transplant Surgery, Zhongnan Hospital, Wuhan University, Wuhan, People’s Republic of China; 4Adelphi University College of Nursing and Public Health, New York, NY, USA; 5Department of Clinical Laboratory of Microbiology, Third Xiangya Hospital, Central South University, Changsha, People’s Republic of ChinaBackground: Drug-resistant Acinetobacter baumannii has become a major problem in liver transplant recipients. The aim of this study was to investigate the clinical presentation, distribution, and drug susceptibility characteristics in liver recipients with A. baumannii infection.Methods: We retrospectively investigated 17 liver recipients who developed A. baumannii infection between January 1, 2007 and December 31, 2014. The distribution of A. baumannii and drug susceptibility characteristics were reviewed.Results: Infectious complications due to A. baumannii appeared in 17 liver recipients, with a total of 24 episodes. Approximately 63% (15/24 of A. baumannii infections occurred within 2 weeks after transplantation. The most common source of infection was multiple culture-positive sites (35.3%, n=6, followed by the intra-abdominal/biliary tract (23.5%, n=4 and lung (23.5%, n=4. Eight patients (47.1% had a body temperature of 38°C or higher at the onset of A. baumannii infection. Nine, seven, and 12 recipients had a serum creatinine level of >1.5 mg/dL, a white blood cell count of >15,000/mm3, and a platelet count of <50,000/mm3, respectively. There were five (29.4% cases of septic shock and eight (47.1% deaths. The rate of antibiotic resistance of A. baumannii to ten of 12 antibiotics investigated was more than 60%. Among the 24 infections caused by A. baumannii, 75% were carbapenem

  2. Bradysia sp. em morangueiro Bradysia sp. in strawberry

    Bernadete Radin

    2009-04-01

    Full Text Available No trabalho, relatam-se os primeiros registros de Bradysia sp. (Insecta: Diptera: Sciaridae em morangueiro (Fragaria x ananassa Duch., cultivado no Município de Eldorado do Sul, RS. O cultivo foi realizado em sacolas com três metros de comprimento, preenchidas com substrato composto de casca de arroz e turfa, dispostas horizontalmente sobre bancadas de madeira, em ambiente protegido. A presença de Bradysia sp. foi observada na segunda quinzena de agosto de 2005. Neste trabalho, estão descritos os sintomas apresentados no morangueiro pela praga, prováveis conseqüências sobre o aparecimento de doenças e uma breve descrição morfológica da Bradysia sp., adulto e fase larval.This paper describes the first record of Bradysia sp. (Insecta; Diptera; Sciaridae in strawberry (Fragaria x ananassa, cultivated in the city of Eldorado do Sul, RS, Brazil. Strawberry was planted in plastic bags filled with a mixture of burnt rice hulls and peat and cultivated in a greenhouse. The presence of Bradysia sp was noticed in the second fortnight of August, 2005. The symptoms in strawberry and the probable consequences in terms of disease arising were described in the present study, as well as the morphological characterization of Bradysia sp. and its illustrations.

  3. Prophage induction and differential RecA and UmuDAb transcriptome regulation in the DNA damage responses of Acinetobacter baumannii and Acinetobacter baylyi.

    Janelle M Hare

    Full Text Available The SOS response to DNA damage that induces up to 10% of the prokaryotic genome requires RecA action to relieve LexA transcriptional repression. In Acinetobacter species, which lack LexA, the error-prone polymerase accessory UmuDAb is instead required for ddrR induction after DNA damage, suggesting it might be a LexA analog. RNA-Seq experiments defined the DNA damage transcriptome (mitomycin C-induced of wild type, recA and umuDAb mutant strains of both A. baylyi ADP1 and A. baumannii ATCC 17978. Of the typical SOS response genes, few were differentially regulated in these species; many were repressed or absent. A striking 38.4% of all ADP1 genes, and 11.4% of all 17978 genes, were repressed under these conditions. In A. baylyi ADP1, 66 genes (2.0% of the genome, including a CRISPR/Cas system, were DNA damage-induced, and belonged to four regulons defined by differential use of recA and umuDAb. In A. baumannii ATCC 17978, however, induction of 99% of the 152 mitomycin C-induced genes depended on recA, and only 28 of these genes required umuDAb for their induction. 90% of the induced A. baumannii genes were clustered in three prophage regions, and bacteriophage particles were observed after mitomycin C treatment. These prophages encoded esvI, esvK1, and esvK2, ethanol-stimulated virulence genes previously identified in a Caenorhabditis elegans model, as well as error-prone polymerase alleles. The induction of all 17978 error-prone polymerase alleles, whether prophage-encoded or not, was recA dependent, but only these DNA polymerase V-related genes were de-repressed in the umuDAb mutant in the absence of DNA damage. These results suggest that both species possess a robust and complex DNA damage response involving both recA-dependent and recA-independent regulons, and further demonstrates that although umuDAb has a specialized role in repressing error-prone polymerases, additional regulators likely participate in these species' transcriptional

  4. SP-100 advanced technology program

    The goal of the triagency SP-100 Program is to develop long-lived, compact, lightweight, survivable nuclear reactor space power systems for application to the power range 50 kWe to 1 MWe. The successful development of these systems should enable or significantly enhance many of the future NASA civil and commercial missions. The NASA SP-100 Advanced Technology Program strongly augments the parallel SP-100 Ground Engineering System Development program and enhances the chances for success of the overall SP-100 program. The purpose of this paper is to discuss the key technical elements of the Advanced Technology Program and the progress made in the initial year and a half of the project

  5. Organic Nutrition of Beggiatoa sp

    1981-01-01

    Culture OH-75-B of Beggiatoa sp. differed significantly from any described previously in its utilization of organic carbon and reduced sulfur compounds. It deposited internal sulfur granules characteristic of Beggiatoa sp. with either sulfide or thiosulfate in the medium. This strain (OH-75-B, clone 2a) could be grown in agitated liquid cultures on mineral medium with acetate as the only source of organic carbon. The resultant growth yields and rates were comparable to those for typical heter...

  6. Optimal spænding i kajakken

    Rossing, Niels Nygaard

    2012-01-01

    Artiklens overordnede fokus er, hvilken betydning den enkelte kajakroers spændingsniveau har for præstationen. Artiklen svarer på, hvad et spændingsniveau er, hvilke kilder der er til spænding, og sidst hvad man kan gøre for at finde sit optimale spændingsniveau....

  7. En moderne spøgelseshistorie

    Simonsen, Karen-Margrethe

    2011-01-01

    Anmeldelse af César Airas "Spøgelserne". Anmeldelsen indkredser bla. spøgelsernes karakter i denne moderne, interkulturelle historie......Anmeldelse af César Airas "Spøgelserne". Anmeldelsen indkredser bla. spøgelsernes karakter i denne moderne, interkulturelle historie...

  8. Visual Evidence of Horizontal Gene Transfer between Plants and Bacteria in the Phytosphere of Transplastomic Tobacco▿ †

    Pontiroli, Alessandra; Rizzi, Aurora; Simonet, Pascal; Daffonchio, Daniele; Vogel, Timothy M.; Monier, Jean-Michel

    2009-01-01

    Plant surfaces, colonized by numerous and diverse bacterial species, are often considered hot spots for horizontal gene transfer (HGT) between plants and bacteria. Plant DNA released during the degradation of plant tissues can persist and remain biologically active for significant periods of time, suggesting that soil or plant-associated bacteria could be in direct contact with plant DNA. In addition, nutrients released during the decaying process may provide a copiotrophic environment conducive for opportunistic microbial growth. Using Acinetobacter baylyi strain BD413 and transplastomic tobacco plants harboring the aadA gene as models, the objective of this study was to determine whether specific niches could be shown to foster bacterial growth on intact or decaying plant tissues, to develop a competence state, and to possibly acquire exogenous plant DNA by natural transformation. Visualization of HGT in situ was performed using A. baylyi strain BD413(rbcL-ΔPaadA::gfp) carrying a promoterless aadA::gfp fusion. Both antibiotic resistance and green fluorescence phenotypes were restored in recombinant bacterial cells after homologous recombination with transgenic plant DNA. Opportunistic growth occurred on decaying plant tissues, and a significant proportion of the bacteria developed a competence state. Quantification of transformants clearly supported the idea that the phytosphere constitutes a hot spot for HGT between plants and bacteria. The nondisruptive approach used to visualize transformants in situ provides new insights into environmental factors influencing HGT for plant tissues. PMID:19329660

  9. Visual evidence of horizontal gene transfer between plants and bacteria in the phytosphere of transplastomic tobacco.

    Pontiroli, Alessandra; Rizzi, Aurora; Simonet, Pascal; Daffonchio, Daniele; Vogel, Timothy M; Monier, Jean-Michel

    2009-05-01

    Plant surfaces, colonized by numerous and diverse bacterial species, are often considered hot spots for horizontal gene transfer (HGT) between plants and bacteria. Plant DNA released during the degradation of plant tissues can persist and remain biologically active for significant periods of time, suggesting that soil or plant-associated bacteria could be in direct contact with plant DNA. In addition, nutrients released during the decaying process may provide a copiotrophic environment conducive for opportunistic microbial growth. Using Acinetobacter baylyi strain BD413 and transplastomic tobacco plants harboring the aadA gene as models, the objective of this study was to determine whether specific niches could be shown to foster bacterial growth on intact or decaying plant tissues, to develop a competence state, and to possibly acquire exogenous plant DNA by natural transformation. Visualization of HGT in situ was performed using A. baylyi strain BD413(rbcL-DeltaPaadA::gfp) carrying a promoterless aadA::gfp fusion. Both antibiotic resistance and green fluorescence phenotypes were restored in recombinant bacterial cells after homologous recombination with transgenic plant DNA. Opportunistic growth occurred on decaying plant tissues, and a significant proportion of the bacteria developed a competence state. Quantification of transformants clearly supported the idea that the phytosphere constitutes a hot spot for HGT between plants and bacteria. The nondisruptive approach used to visualize transformants in situ provides new insights into environmental factors influencing HGT for plant tissues. PMID:19329660

  10. Fungi Association with Cedar’s Seeds and Fusarium sp. and Pestalotia sp. Pathogenicities Levantamento de Fungos em Sementes de Cedro e Avaliação da Patogenicidade de Fusarium sp. e Pestalotia sp.

    Sílvia Cristina Benetti; Álvaro Figueredo dos Santos; Antonio Carlos de Souza Medeiros; David de Souza Jaccoud Filho

    2010-01-01

    This research had as main objectives the evaluation of cedar’s seeds seed-borne fungi and the Fusarium
    sp. and Pestalotia sp. pathogenicities. For the fungi detection Potato Dextrose and Agar medium and Blotter
    test methods were used. For the pathogenicity tests, isolates of Fusarium sp. and Pestalotia sp. were used. The following fungi were observed: Pestalotia sp., Fusarium sp., Phomopsis sp., Colletotrichum sp., Macrophomina sp. and Cladosporium sp. The fungi...

  11. Synergistic Effect of Oleanolic Acid on Aminoglycoside Antibiotics against Acinetobacter baumannii.

    Bora Shin

    Full Text Available Difficulties involved in treating drug-resistant pathogens have created a need for new therapies. In this study, we investigated the possibility of using oleanolic acid (OA, a natural pentacyclic triterpenoid, as a natural adjuvant for antibiotics against Acinetobacter baumannii. High concentrations of OA can kill cells, partly because it generates reactive oxygen species. Measurement of the fractional inhibitory concentration (FIC for OA and time-kill experiments demonstrated that it only synergizes with aminoglycoside antibiotics (e.g., gentamicin, kanamycin. Other classes of antibiotics (e.g., ampicillin, rifampicin, norfloxacin, chloramphenicol, and tetracycline have no interactions with OA. Microarray and quantitative reverse transcription-PCR analysis indicated that genes involved in ATP synthesis and cell membrane permeability, the gene encoding glycosyltransferase, peptidoglycan-related genes, phage-related genes, and DNA repair genes were upregulated under OA. OA highly induces the expression of adk, which encodes an adenylate kinase, and des6, which encodes a linoleoyl-CoA desaturase, and deletion of these genes increased FICs; these observations indicate that adk and des6 are involved in the synergism of OA with aminoglycosides. Data obtained using 8-anilino-1-naphthalenesulfonic acid, fluorescence-conjugated gentamicin, and membrane fatty acid analysis indicates that adk and des6 are involved in changes in membrane permeability. Proton-motive force and ATP synthesis tests show that those genes are also involved in energy metabolism. Taken together, our data show that OA boosts aminoglycoside uptake by changing membrane permeability and energy metabolism in A. baumannii.

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

    Miyasaki, Yoko; Rabenstein, John D; Rhea, Joshua; Crouch, Marie-Laure; Mocek, Ulla M; Kittell, Patricia Emmett; Morgan, Margie A; Nichols, Wesley Stephen; Van Benschoten, M M; Hardy, William David; Liu, George Y

    2013-01-01

    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. PMID:23630600

  13. Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal

    Goel Vikas

    2001-08-01

    Full Text Available Abstract Background Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. Results/ Discussion Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses four new outer membrane proteins,with molecular weight ranging from 77 kDa to 88 kDa, that are called Iron Regulated Outer Membrane Proteins (IROMPs. We studied the functional and immunological properties of IROMPs expressed by A.baumanii ATCC 19606.The bands corresponding to IROMPs were eluted from SDS-PAGE and were used to immunize BALB/c mice for the production of monoclonal antibodies. Hybridomas secreting specific antibodies against these IROMPs were selected after screening by ELISA and their reactivity was confirmed by Western Blot. The antibodies then generated belonged to IgM isotype and showed bactericidical and opsonising activities against A.baumanii in vitro.These antibodies also blocked siderophore mediated iron uptake via IROMPs in bacteria. Conclusion This proves that iron uptake via IROMPs,which is mediated through siderophores,may have an important role in the survival of A.baumanii inside the host,and helps establishing the infection.

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

    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.

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

    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.

  16. Detoxification of Indole by an Indole-Induced Flavoprotein Oxygenase from Acinetobacter baumannii.

    Guang-Huey Lin

    Full Text Available Indole, a derivative of the amino acid tryptophan, is a toxic signaling molecule, which can inhibit bacterial growth. To overcome indole-induced toxicity, many bacteria have developed enzymatic defense systems to convert indole to non-toxic, water-insoluble indigo. We previously demonstrated that, like other aromatic compound-degrading bacteria, Acinetobacter baumannii can also convert indole to indigo. However, no work has been published investigating this mechanism. Here, we have shown that the growth of wild-type A. baumannii is severely inhibited in the presence of 3.5 mM indole. However, at lower concentrations, growth is stable, implying that the bacteria may be utilizing a survival mechanism to oxidize indole. To this end, we have identified a flavoprotein oxygenase encoded by the iifC gene of A. baumannii. Further, our results suggest that expressing this recombinant oxygenase protein in Escherichia coli can drive indole oxidation to indigo in vitro. Genome analysis shows that the iif operon is exclusively present in the genomes of A. baumannii and Pseudomonas syringae pv. actinidiae. Quantitative PCR and Western blot analysis also indicate that the iif operon is activated by indole through the AraC-like transcriptional regulator IifR. Taken together, these data suggest that this species of bacteria utilizes a novel indole-detoxification mechanism that is modulated by IifC, a protein that appears to be, at least to some extent, regulated by IifR.

  17. Detoxification of Indole by an Indole-Induced Flavoprotein Oxygenase from Acinetobacter baumannii.

    Lin, Guang-Huey; Chen, Hao-Ping; Shu, Hung-Yu

    2015-01-01

    Indole, a derivative of the amino acid tryptophan, is a toxic signaling molecule, which can inhibit bacterial growth. To overcome indole-induced toxicity, many bacteria have developed enzymatic defense systems to convert indole to non-toxic, water-insoluble indigo. We previously demonstrated that, like other aromatic compound-degrading bacteria, Acinetobacter baumannii can also convert indole to indigo. However, no work has been published investigating this mechanism. Here, we have shown that the growth of wild-type A. baumannii is severely inhibited in the presence of 3.5 mM indole. However, at lower concentrations, growth is stable, implying that the bacteria may be utilizing a survival mechanism to oxidize indole. To this end, we have identified a flavoprotein oxygenase encoded by the iifC gene of A. baumannii. Further, our results suggest that expressing this recombinant oxygenase protein in Escherichia coli can drive indole oxidation to indigo in vitro. Genome analysis shows that the iif operon is exclusively present in the genomes of A. baumannii and Pseudomonas syringae pv. actinidiae. Quantitative PCR and Western blot analysis also indicate that the iif operon is activated by indole through the AraC-like transcriptional regulator IifR. Taken together, these data suggest that this species of bacteria utilizes a novel indole-detoxification mechanism that is modulated by IifC, a protein that appears to be, at least to some extent, regulated by IifR. PMID:26390211

  18. Outbreak of septicaemic cases caused by Acinetobacter ursingii in a neonatal intensive care unit.

    Máder, Krisztina; Terhes, Gabriella; Hajdú, Edit; Urbán, Edit; Sóki, József; Magyar, Tibor; Márialigeti, Károly; Katona, Márta; Nagy, Elisabeth; Túri, Sándor

    2010-06-01

    Neonatal infections may be caused by various microorganisms, but as far as we are aware, Acinetobacter ursingii has not yet been reported in connection with nosocomial infections of premature infants. During 2 months, 3 premature babies were treated with nosocomial infection caused by A. ursingii at the same ward, and on the basis of molecular typing results the same strain was responsible for all of these cases. Traditional biochemical methods and automatic identification systems failed to identify this bacterium on the species level, and only 16S rDNA sequencing gave acceptable species identifications. The isolated strains proved to be susceptible to all of the tested antimicrobials, including ampicillin/sulbactam, doxycyclin, netilmicin, ciprofloxacin, piperacillin/tazobactam, ceftazidime, imipenem, meropenem, trimethoprim/sulfametoxazole, gentamicin, tobramycin, amikacin, and levofloxacin according to the CLSI standard. In spite of the environmental screening, the source of the infection could not be clarified. One of 3 neonates died, the others recovered and were discharged home after several months of hospitalization. PMID:19931486

  19. Emergence and clonal dissemination of carbapenem-hydrolysing OXA-58-producing Acinetobacter baumannii isolates in Bolivia.

    Sevillano, Elena; Fernández, Elena; Bustamante, Zulema; Zabalaga, Silvia; Rosales, Ikerne; Umaran, Adelaida; Gallego, Lucía

    2012-01-01

    Acinetobacter baumannii is an emerging multidrug-resistant pathogen and very little information is available regarding its imipenem resistance in Latin American countries such as Bolivia. This study investigated the antimicrobial resistance profile of 46 clinical strains from different hospitals in Cochabamba, Bolivia, from March 2008 to July 2009, and the presence of carbapenemases as a mechanism of resistance to imipenem. Isolates were obtained from 46 patients (one isolate per patient; 30 males,16 females) with an age range of 1 day to 84 years, and were collected from different sample types, the majority from respiratory tract infections (17) and wounds (13). Resistance to imipenem was detected in 15 isolates collected from different hospitals of the city. These isolates grouped into the same genotype, named A, and were resistant to all antibiotics tested including imipenem, with susceptibility only to colistin. Experiments to detect carbapenemases revealed the presence of the OXA-58 carbapenemase. Further analysis revealed the location of the bla(OXA-58) gene on a 40 kb plasmid. To our knowledge, this is the first report of carbapenem resistance in A. baumannii isolates from Bolivia that is conferred by the OXA-58 carbapenemase. The presence of this gene in a multidrug-resistant clone and its location within a plasmid is of great concern with regard to the spread of carbapenem-resistant A. baumannii in the hospital environment in Bolivia. PMID:21873380

  20. Production and characterization of bioemulsifier from a marine bacterium, Acinetobacter calcoaceticus subsp. anitratus SM7

    Kulnaree Phetrong

    2008-05-01

    Full Text Available Marine bacterium strain SM7 was isolated as a bioemulsifier-producing bacterium from oil-spilled seawater in Songkhla lagoon, Thailand. It was identified as Acinetobacter calcoaceticus subsp. anitratus based on morphology, biochemicalcharacteristics and 16S rRNA sequence. A. calcoaceticus subsp. anitratus SM7 produced an extracellular emulsifying agent when grown in a minimal salt medium (pH 7.0 containing 0.3% (v/v n-heptadecane and 0.1% (w/v ammoniumhydrogen carbonate as carbon source and nitrogen source, respectively, at 30oC with agitation rate of 200 rpm. Crude bioemulsifier was recovered from the culture supernatant by ethanol precipitation with a yield of 2.94 g/l and had a criticalemulsifier concentration of 0.04 g/ml. The crude bioemulsifier was capable of emulsifying n-hexadecane in a broad pH range (6-12, temperatures (30-121oC and in the presence of NaCl up to 12% (w/v. The bioemulsifier was stable in saltsolution ranging from 0 to 0.1% (w/v of MgCl2 and CaCl2. The broad range of pH stability, thermostability and salt tolerance suggested that the bioemulsifier from A. calcoaceticus subsp. anitratus SM7 could be useful in environmentalapplication, especially bioremediation of oil-polluted seawater.

  1. The effect of silver or gallium doped titanium against the multidrug resistant Acinetobacter baumannii.

    Cochis, A; Azzimonti, B; Della Valle, C; De Giglio, E; Bloise, N; Visai, L; Cometa, S; Rimondini, L; Chiesa, R

    2016-02-01

    Implant-related infection of biomaterials is one of the main causes of arthroplasty and osteosynthesis failure. Bacteria, such as the rapidly-emerging Multi Drug Resistant (MDR) pathogen Acinetobacter Baumannii, initiate the infection by adhering to biomaterials and forming a biofilm. Since the implant surface plays a crucial role in early bacterial adhesion phases, titanium was electrochemically modified by an Anodic Spark Deposition (ASD) treatment, developed previously and thought to provide osseo-integrative properties. In this study, the treatment was modified to insert gallium or silver onto the titanium surface, to provide antibacterial properties. The material was characterized morphologically, chemically, and mechanically; biological properties were investigated by direct cytocompatibility assay, Alkaline Phosphatase (ALP) activity, Scanning Electron Microscopy (SEM), and Immunofluorescent (IF) analysis; antibacterial activity was determined by counting Colony Forming Units, and viability assay. The various ASD-treated surfaces showed similar morphology, micrometric pore size, and uniform pore distribution. Of the treatments studied, gallium-doped specimens showed the best ALP synthesis and antibacterial properties. This study demonstrates the possibility of successfully doping the surface of titanium with gallium or silver, using the ASD technique; this approach can provide antibacterial properties and maintain high osseo-integrative potential. PMID:26708086

  2. Oxacillinase (OXA-producing Acinetobacter baumannii in Brazil: clinical and environmental impact and therapeutic options

    Micheli Medeiros

    2013-12-01

    Full Text Available Following a worldwide trend, infections caused by MDR OXA-type (Ambler class D carbapenemase-producing Acinetobacter baumannii are currently regarded as a clinical and epidemiological emergency in Brazil. OXA-producing A. baumannii strains have been identified in the states of Alagoas, Amazonas, Bahia, Distrito Federal, Espírito Santo, Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Paraná, Pernambuco, Rio de Janeiro, Rio Grande do Norte, Rio Grande do Sul, Santa Catarina and São Paulo. In some settings, the presence of OXA-23- and/or OXA-143 -producing A. baumannii (so far restricted to Brazil has been endemic and A. baumannii strains carrying blaOXA-23 genes have been detected in hospital wastewater effluents, hence a potential risk to the community and the environment. Although molecular typing by multilocus sequence typing (MLST - Bartual scheme, University of Oxford, http://pubmlst.org/abaumannii/ has revealed the international spread of a clonal complex (CC denominated CC92, in Brazil most OXA-23-producing A. baumannii belong to CC113, CC109 or CC104 clonal complexes. Finally, from a clinical point of view, the main problem of A. baumannii infections is the limited use of antibacterial agents with in vitro activity, often restricted to ampicillin/sulbactam, polymyxin B and/or colistin (polymyxin E.

  3. Higher isolation of NDM-1 producing Acinetobacter baumannii from the sewage of the hospitals in Beijing.

    Chuanfu Zhang

    Full Text Available Multidrug resistant microbes present in the environment are a potential public health risk. In this study, we investigate the presence of New Delhi metallo-β-lactamase 1 (NDM-1 producing bacteria in the 99 water samples in Beijing City, including river water, treated drinking water, raw water samples from the pools and sewage from 4 comprehensive hospitals. For the bla NDM-1 positive isolate, antimicrobial susceptibility testing was further analyzed, and Pulsed Field Gel Electrophoresis (PFGE was performed to determine the genetic relationship among the NDM-1 producing isolates from sewage and human, as well as the clinical strains without NDM-1. The results indicate that there was a higher isolation of NDM-1 producing Acinetobacter baumannii from the sewage of the hospitals, while no NDM-1 producing isolates were recovered from samples obtained from the river, drinking, or fishpond water. Surprisingly, these isolates were markedly different from the clinical isolates in drug resistance and pulsed field gel electrophoresis profiles, suggesting different evolutionary relationships. Our results showed that the hospital sewage may be one of the diffusion reservoirs of NDM-1 producing bacteria.

  4. In vitro effects of sulbactam combinations with different antibiotic groups against clinical Acinetobacter baumannii isolates.

    Deveci, Aydin; Coban, Ahmet Yilmaz; Acicbe, Ozlem; Tanyel, Esra; Yaman, Gorkem; Durupinar, Belma

    2012-10-01

    Treatment of multidrug resistant (MDR) Acinetobacter baumannii infections causes some problems as a result of possessing various antibacterial resistance mechanisms against available antibiotics. Combination of antibiotics, acting by different mechanisms, is used for the treatment of MDR bacterial infections. It is an important factor to determine synergy or antagonism between agents in the combination for the constitution of effective therapy. The study aimed to determine In vitro interactions interpreted according to calculated fractional inhibitory concentration (FIC) index between sulbactam and ceftazidime, ceftriaxone, cefepime, ciprofloxacin, gentamicin, meropenem, tigecycline, and colistin. Ten clinical isolates of A. baumannii were tested for determination of synergistic effects of sulbactam with different antimicrobial combinations. Minimal inhibitory concentration (MIC) values of both sulbactam and combined antibiotics decreased 2- to 128-fold. Synergy and partial synergy were determined in combination of sulbactam with ceftazidime and gentamicin (FIC index: ≤ 0.5 or >0.5 to sulbactam. Although synergistic and partial synergistic effects were observed in the combination of sulbactam and ceftriaxone, all isolates remained resistant to ceftriaxone. The effect of cefepime-sulbactam combination was synergy in five, partial synergy in one and indifferent in four isolates. Meropenem and sulbactam showed a partial synergistic effect (FIC index: >0.5 to 1-2) in six isolates. Antagonism was not determined in any combination for clinical A. baumannii isolates in the study. In conclusion, sulbactam is a good candidate for combination treatment regimes for MDR A. baumannii infections. PMID:23182043

  5. Wide Distribution of Carbapenem Resistant Acinetobacter baumannii in Burns Patients in Iran

    zahra eFarshadzadeh

    2015-10-01

    Full Text Available Antimicrobial resistance in carbapenem non-susceptible Acinetobacter baumannii (CNSAb is a major public health concern globally. This study determined the antibiotic resistance and molecular epidemiology of CNSAb isolates from a referral burn center in Tehran, Iran.Sixty-nine CNSAb isolates were tested for susceptibility to antimicrobial agents using the E-test methodology. Multiple locus variable number tandem repeat analysis (MLVA, Multilocus sequence typing and multiplex PCR were performed. PCR assays tested for ambler classes A, B, and D β-lactamases. Detection of ISAba1, characterization of integrons, and biofilm formation were investigated.Fifty-three (77% isolates revealed XDR phenotypes. High prevalence of blaOXA-23-like (88% and blaPER-1 (54% were detected. ISAba1 was detected upstream of blaADC, blaOXA-23-like and blaOXA51-like genes in, 97, 42 and 26% of isolates, respectively. Thirty-one (45% isolates were assigned to International Clone (IC variants. MLVA identified 56 distinct types with 6 clusters and 53 singleton genotypes. Forty previously known MLST sequence types forming 5 clonal complexes were identified. The Class 1 integron (class 1 integrons gene was identified in 84% of the isolates. The most prevalent (33% cassette combination was aacA4-catB8-aadA1. The IC variants were predominant in the A. baumannii lineage with the ability to form strong biofilms.The XDR-CNSAb from burned patients

  6. Acinetobacter baumannii phenylacetic acid metabolism influences infection outcome through a direct effect on neutrophil chemotaxis.

    Bhuiyan, Md Saruar; Ellett, Felix; Murray, Gerald L; Kostoulias, Xenia; Cerqueira, Gustavo M; Schulze, Keith E; Mahamad Maifiah, Mohd Hafidz; Li, Jian; Creek, Darren J; Lieschke, Graham J; Peleg, Anton Y

    2016-08-23

    Innate cellular immune responses are a critical first-line defense against invading bacterial pathogens. Leukocyte migration from the bloodstream to a site of infection is mediated by chemotactic factors that are often host-derived. More recently, there has been a greater appreciation of the importance of bacterial factors driving neutrophil movement during infection. Here, we describe the development of a zebrafish infection model to study Acinetobacter baumannii pathogenesis. By using isogenic A. baumannii mutants lacking expression of virulence effector proteins, we demonstrated that bacterial drivers of disease severity are conserved between zebrafish and mammals. By using transgenic zebrafish with fluorescent phagocytes, we showed that a mutation of an established A. baumannii global virulence regulator led to marked changes in neutrophil behavior involving rapid neutrophil influx to a localized site of infection, followed by prolonged neutrophil dwelling. This neutrophilic response augmented bacterial clearance and was secondary to an impaired A. baumannii phenylacetic acid catabolism pathway, which led to accumulation of phenylacetate. Purified phenylacetate was confirmed to be a neutrophil chemoattractant. These data identify a previously unknown mechanism of bacterial-guided neutrophil chemotaxis in vivo, providing insight into the role of bacterial metabolism in host innate immune evasion. Furthermore, the work provides a potentially new therapeutic paradigm of targeting a bacterial metabolic pathway to augment host innate immune responses and attenuate disease. PMID:27506797

  7. Biological detoxification of Cr(VI) using wood-husk immobilized Acinetobacter haemolyticus

    Zakaria, Zainul Akmar; Zakaria, Zainoha [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Surif, Salmijah [Department of Environmental Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Ahmad, Wan Azlina [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)], E-mail: azlina@kimia.fs.utm.my

    2007-09-05

    Acinetobacter haemolyticus, a Gram-negative aerobic locally isolated bacterium, immobilized on wood-husk showed the ability to detoxify Cr(VI) to Cr(III). Wood-husk, a natural cellulose-based support material, packed in an upward-flow column was used as support material for bacterial attachment. Around 97% of the Cr(VI) in wastewater containing 15 mg L{sup -1} of Cr(VI) was reduced at a flow rate of 8.0 mL min{sup -1}. The wastewater containing Cr(VI) was added with liquid pineapple wastewater as nutrient source for the bacteria. Electron microscopic examinations of the wood-husk after 42 days of column operation showed gradual colonization of the wood-husk by bacterial biofilm. The use of 0.1% (v/v) formaldehyde as a disinfecting agent inhibited growth of bacteria present in the final wastewater discharge. This finding is important in view of the ethical code regarding possible introduction of exogenous bacterial species into the environment.

  8. Hexavalent chromium reduction by Acinetobacter haemolyticus isolated from heavy-metal contaminated wastewater

    Zakaria, Zainul Akmar [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Zakaria, Zainoha [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Surif, Salmijah [Department of Environmental Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Ahmad, Wan Azlina [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)]. E-mail: azlina@kimia.fs.utm.my

    2007-07-19

    Possible application of a locally isolated environmental isolate, Acinetobacter haemolyticus to remediate Cr(VI) contamination in water system was demonstrated. Cr(VI) reduction by A. haemolyticus seems to favour the lower concentrations (10-30 mg/L). However, incomplete Cr(VI) reduction occurred at 70-100 mg/L Cr(VI). Initial specific reduction rate increased with Cr(VI) concentrations. Cr(VI) reduction was not affected by 1 or 10 mM sodium azide (metabolic inhibitor), 10 mM of PO{sub 4} {sup 3-}, SO{sub 4} {sup 2-}, SO{sub 3} {sup 2-}, NO{sub 3} {sup -} or 30 mg/L of Pb(II), Zn(II), Cd(II) ions. However, heat treatment caused significant dropped in Cr(VI) reduction to less than 20% only. A. haemolyticus cells loses its shape and size after exposure to 10 and 50 mg Cr(VI)/L as revealed from TEM examination. The presence of electron-dense particles in the cytoplasmic region of the bacteria suggested deposition of chromium in the cells.

  9. Crystal structure of 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase from the ESKAPE pathogen Acinetobacter baumannii.

    Sutton, Kristin A; Breen, Jennifer; Russo, Thomas A; Schultz, L Wayne; Umland, Timothy C

    2016-03-01

    The enzyme 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase catalyzes the sixth step of the seven-step shikimate pathway. Chorismate, the product of the pathway, is a precursor for the biosynthesis of aromatic amino acids, siderophores and metabolites such as folate, ubiquinone and vitamin K. The shikimate pathway is present in bacteria, fungi, algae, plants and apicomplexan parasites, but is absent in humans. The EPSP synthase enzyme produces 5-enolpyruvylshikimate 3-phosphate and phosphate from phosphoenolpyruvate and shikimate 3-phosphate via a transferase reaction, and is the target of the herbicide glyphosate. The Acinetobacter baumannii gene encoding EPSP synthase, aroA, has previously been demonstrated to be essential during host infection for the growth and survival of this clinically important drug-resistant ESKAPE pathogen. Prephenate dehydrogenase is also encoded by the bifunctional A. baumannii aroA gene, but its activity is dependent upon EPSP synthase since it operates downstream of the shikimate pathway. As part of an effort to evaluate new antimicrobial targets, recombinant A. baumannii EPSP (AbEPSP) synthase, comprising residues Ala301-Gln756 of the aroA gene product, was overexpressed in Escherichia coli, purified and crystallized. The crystal structure, determined to 2.37 Å resolution, is described in the context of a potential antimicrobial target and in comparison to EPSP synthases that are resistant or sensitive to the herbicide glyphosate. PMID:26919521

  10. Isolation and characterization of a newly isolated pyrene-degrading Acinetobacter strain USTB-X.

    Yuan, Haiyan; Yao, Jun; Masakorala, Kanaji; Wang, Fei; Cai, Minmin; Yu, Chan

    2014-02-01

    The pryene-degradation bacterium strain USTB-X was newly isolated from the polycyclic aromatic hydrocarbon (PAH)-contaminated soil in Beijing Coking Plant, China. The strain was identified as Acinetobacter with respect to its 16S rDNA and morphological and physiological characteristics. The strain was Gram-negative, non-mobile, non-acid-fast, and non-spore-forming, short rods in young culture and 0.8-1.6 μm in diameter and 1.2-2.5 μm long in the stationary phase of growth. Strain USTB-X could utilize pyrene, naphthalene, fluorene, phenanthrene, benzene, toluene, ethylbenzene, ethanol, methanol, and Tween 80 as sole source of carbon and energy. The strain could produce biosurfactants which enhanced the removal of pyrene and could remove 63 % of pyrene with an initial concentration of 100 mg·L-1 in 16 days without other substrates. Based on the intermediates analyzed by gas chromatography-mass spectrometry, we also deduced the possible metabolic pathway of strain USTBX for pyrene biodegradation. Results indicated that the strain USTB-X had high potential to enhance the removal of PAHs in contaminated sites. PMID:24122268

  11. Enhanced Efficacy of Combinations of Pexiganan with Colistin Versus Acinetobacter Baumannii in Experimental Sepsis.

    Cirioni, Oscar; Simonetti, Oriana; Pierpaoli, Elisa; Barucca, Alessandra; Ghiselli, Roberto; Orlando, Fiorenza; Pelloni, Maria; Minardi, Daniele; Trombettoni, Maria Michela Cappelletti; Guerrieri, Mario; Offidani, Annamaria; Giacometti, Andrea; Provinciali, Mauro

    2016-08-01

    We investigated the efficacy of colistin combined with pexiganan in experimental mouse models of Acinetobacter baumannii infection.Adult male BALB/c mice received intraperitoneally 1 mL saline containing 2 × 10 CFU of susceptible and multiresistant A. baumannii. Two hours after bacterial challenge, animals received 1 mg/kg of colistin, 1 mg/kg of pexiganan, or 1 mg/kg of colistin plus 1 mg/kg of pexiganan.Blood culture positivity, the quantities of bacteria in the intra-abdominal fluid, the rate of lethality and immunological studies, such as immunophenotyping and NK cytotoxicity, were evaluated.In the in vitro study, A. baumannii showed susceptibility to colistin and pexiganan and a strong synergy was observed by testing colistin combined with pexiganan with fractionary inhibitory concentration index of 0.312 for both strains.In the in vivo study colistin or pexiganan alone showed a good antimicrobial efficacy. When colistin was combined with pexiganan, the positive interaction produced low bacterial counts that were statistically significant versus singly treated groups. For both strains the highest rate of survival was observed in combined-treated groups (90%).Pexiganan increased NK cytotoxic activity over the levels of infected and colistin-treated animals.In conclusion, pexiganan combined with colistin was found to be efficacious against A. baumannii infection. PMID:26849630

  12. Sensitivity of cultured pancreatic carcinoma cells to Acinetobacter glutaminase-asparaginase.

    Wu, M C; Arimura, G K; Holcenberg, J S; Yunis, A A

    1982-09-01

    Cultured human pancreatic carcinoma cells (MIA PaCa-2) have been shown previously to be very sensitive to E. coli L-asparaginase (EC II). The present studies have demonstrated that another enzyme, Acinetobacter glutaminase-asparaginase (AGA) is much more effective in inhibiting cell growth. At the concentration of 0.0025 U/ml of AGA activity the enzyme totally inhibited cell growth, whereas the EC II with the same concentration did not show any effect. The inhibition of cell growth correlated well with inhibition of protein and glycoprotein synthesis. The addition of L-glutamine at the concentration of 1 mM completely reversed the inhibition of protein synthesis. Similarly, the addition of L-glutamine at the concentration of 3 mM daily on 3 successive days after adding AGA resulted in significant reversal of growth inhibition. The results of this study indicate that the action of AGA on MIA PaCa-2 is, to a great extent, exerted through its L-glutaminase activity. PMID:7173949

  13. Cloning, expression, and characterization of a novel diketoreductase from Acinetobacter baylyi

    Xuri Wu; Nan Liu; Yunmian He; Yijun Chen

    2009-01-01

    Reductions of carbonyl groups catalyzed by oxidoreduc-tases are involved in all biological processes and are often a class of important biocatalyst. In this article, we report a novel enzyme designated as diketoreductase (DKR) that was able to reduce two carbonyl groups in a diketo ester to corresponding dihydroxy ester with excel-lent stereoselectivity. The DKR was cloned from Acinetobacter baylyi by reverse genetic method, heteroge-neously expressed in Escherichia coli, and purified to homogeneity by two chromatographic steps. This novel enzyme exhibited dual cofactor specificity, with a prefer-ence of NADH over NADPH. The dihydroxy ester product catalyzed by the DKR was only 3R,5S-stereoi-somer with both diastereomeric excess and enantiomeric excess values more than 99.5%. In addition, some bio-chemical properties of the enzyme, such as the optimal pH and temperature, were also characterized. Furthermore, sequence analysis indicated that this new enzyme was homologous to bacterial 3-hydroxyacyl coenzyme-A dehydrogenase. More importantly, based on the unique catalytic activity and excellent stereoselec-tivity, the DKR could be utilized in the synthesis of valuable chiral drug intermediates, such as Lipitor .

  14. Aptamer-nanobody based ELASA for specific detection of Acinetobacter baumannii isolates.

    Rasoulinejad, Samaneh; Gargari, Seyed Latif Mousavi

    2016-08-10

    Acinetobacter baumannii has turned into an important threat in nosocomial outbreak infections and multidrug resistance leading to high mortality rates in the 21st century. In recent years its mortality has increased by 15% which in part could be due to lack of a rapid and sensitive diagnostic test. In this work we introduced a new detection test for A. baumannii with two highly specific aptamer and nanobody molecules. High binding affinity DNA oligonucleotide aptamers toward A. baumannii were selected through 12 rounds of whole cell System Evolution of Ligands by EXponential enrichment process (SELEX). The SELEX procedures was monitored by flow cytometry. The dissociation constant and binding efficiency of the selected aptamer Aci49 was 7.547±1:353pM and 47.50%, respectively. A sandwich enzyme linked aptamer sorbent assay (ELASA) was designed with the biotinylated Aci49 aptamer and our previously developed nanobody against biofilm associated protein (Bap). The assay system was optimized with A. baumannii (ATCC 19606) and 47 clinical isolates of A. baumannii were tested. The threshold of detection in sandwich ELASA process was10(3) CFU/ml. The sensitivity of test toward the clinical isolates was 95.47%. Our results reveal that the sandwich ELASA is sensitive and specific enough for the rapid detection of A. baumannii from clinical isolates. PMID:27234880

  15. The First Outbreak Caused by Acinetobacter baumannii ST208 and ST195 in China

    Junyan Qu

    2016-01-01

    Full Text Available This study aimed to analyze the clinical characteristics of patients and molecular mechanisms of the first outbreak mainly caused by sequence types (STs 208 multidrug resistant (MDR Acinetobacter baumannii in China. A total of 10 clinical samples were collected from 5 patients who were involved in the outbreak. Bacterial identification and antibiotic sensitivity tests were performed by the VITEK-2 COMPACT automated system. MICs of tigecycline for clinical isolates were determined using broth microdilution. The clonal relatedness of A. baumannii clinical isolates in our local settings was determinated by pulsed-field gel electrophoresis (PFGE and multilocus sequence typing (MLST. A total of 7 A. baumannii strains were isolated and all were MDR strains; two of them were carbapenem-nonsusceptible strains. blaOXA-23 was the only acquired carbapenemase gene in the isolates. The isolates belonged to a single clonal pulsotype determined by PFGE and two sequences types (STs determined by MLST. The isolates belonged to the globally disseminated clonal complex 92, among which ST195 and ST208 were the most common sequence types (71.43% and 28.57%. The outbreak was successfully controlled by stringent infection control measures, especially improving the hand hygiene compliance and enhancing antimicrobial stewardship. In conclusion, this is the first description of an outbreak caused mainly by A. baumannii of ST208 in China. Infection control measures should be strengthened when infection outbreaks in hospital.

  16. Emergence of multidrug-resistant Acinetobacter baumannii producing OXA-23 Carbapenemase in Qatar.

    Rolain, J-M; Loucif, L; Al-Maslamani, M; Elmagboul, E; Al-Ansari, N; Taj-Aldeen, S; Shaukat, A; Ahmedullah, H; Hamed, M

    2016-05-01

    The objective of our study was to describe the molecular support of carbapenem resistance from randomly selected clinical isolates of multidrug-resistant (MDR) Acinetobacter baumannii as a pilot study from the Hamad Medical Corporation (HMC), Qatar. Results of our report will be used to study carbapenemases using molecular techniques in all isolated MDR A. baumannii. Forty-eight MDR A. baumannii were randomly selected from isolates preserved at HMC. Identification of all isolates was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic resistance was tested phenotypically by Phoenix and confirmed by Etest. The molecular support of carbapenemases (bla OXA-23, bla OXA-24, bla OXA-58, bla NDM) was investigated by real-time PCR. The epidemiologic relatedness of the isolates was verified by phylogenetic analysis based on partial sequences of CsuE and bla OXA-51 genes. All 48 isolates were identified as A. baumannii and were confirmed to be resistant to most antibiotics, especially meropenem, imipenems, ciprofloxacin, levofloxacin, amikacin, gentamicin and most of the β-lactams; they were sensitive to colistin. All the isolates were positive for bla OXA-23 and negative for the other tested carbapenemase genes. Clonality analysis demonstrated that different lineages were actually circulating in Qatar; and we suggest that an outbreak occurred in the medical intensive care unit of HMC between 2011 and 2012. Here we report the emergence of MDR A. baumannii producing the carbapenemase OXA-23 in Qatar. PMID:27054039

  17. The First Outbreak Caused by Acinetobacter baumannii ST208 and ST195 in China

    Qu, Junyan; Du, Yu

    2016-01-01

    This study aimed to analyze the clinical characteristics of patients and molecular mechanisms of the first outbreak mainly caused by sequence types (STs) 208 multidrug resistant (MDR) Acinetobacter baumannii in China. A total of 10 clinical samples were collected from 5 patients who were involved in the outbreak. Bacterial identification and antibiotic sensitivity tests were performed by the VITEK-2 COMPACT automated system. MICs of tigecycline for clinical isolates were determined using broth microdilution. The clonal relatedness of A. baumannii clinical isolates in our local settings was determinated by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). A total of 7 A. baumannii strains were isolated and all were MDR strains; two of them were carbapenem-nonsusceptible strains. blaOXA-23 was the only acquired carbapenemase gene in the isolates. The isolates belonged to a single clonal pulsotype determined by PFGE and two sequences types (STs) determined by MLST. The isolates belonged to the globally disseminated clonal complex 92, among which ST195 and ST208 were the most common sequence types (71.43% and 28.57%). The outbreak was successfully controlled by stringent infection control measures, especially improving the hand hygiene compliance and enhancing antimicrobial stewardship. In conclusion, this is the first description of an outbreak caused mainly by A. baumannii of ST208 in China. Infection control measures should be strengthened when infection outbreaks in hospital. PMID:27144176

  18. Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates

    David Chang

    2016-03-01

    Full Text Available Acinetobacter baumannii is a challenging pathogen due to antimicrobial resistance and biofilm development. The role of iron in bacterial physiology has prompted the evaluation of iron-modulation as an antimicrobial strategy. The non-reducible iron analog gallium(III nitrate, Ga(NO33, has been shown to inhibit A. baumannii planktonic growth; however, utilization of heme-iron by clinical isolates has been associated with development of tolerance. These observations prompted the evaluation of iron-heme sources on planktonic and biofilm growth, as well as antimicrobial activities of gallium meso- and protoporphyrin IX (Ga-MPIX and Ga-PPIX, metal heme derivatives against planktonic and biofilm bacteria of multidrug-resistant (MDR clinical isolates of A. baumannii in vitro. Ga(NO33 was moderately effective at reducing planktonic bacteria (64 to 128 µM with little activity against biofilms (≥512 µM. In contrast, Ga-MPIX and Ga-PPIX were highly active against planktonic bacteria (0.25 to 8 µM. Cytotoxic effects in human fibroblasts were observed following exposure to concentrations exceeding 128 µM of Ga-MPIX and Ga-PPIX. We observed that the gallium metal heme conjugates were more active against planktonic and biofilm bacteria, possibly due to utilization of heme-iron as demonstrated by the enhanced effects on bacterial growth and biofilm formation.

  19. Isotherm kinetics of Cr(III) removal by non-viable cells of Acinetobacter haemolyticus.

    Yahya, Siti Khairunnisa; Zakaria, Zainul Akmar; Samin, Jefri; Raj, A S Santhana; Ahmad, Wan Azlina

    2012-06-01

    The potential use of non-viable biomass of a Gram negative bacterium i.e. Acinetobacter haemolyticus to remove Cr(III) species from aqueous environment was investigated. Highest Cr(III) removal of 198.80 mg g(-1) was obtained at pH 5, biomass dosage of 15 mg cell dry weight, initial Cr(III) of 100 mg L(-1) and 30 min of contact time. The Langmuir and Freundlich models fit the experimental data (R(2)>0.95) while the kinetic data was best described using the pseudo second-order kinetic model (R(2)>0.99). Cr(III) was successfully recovered from the bacterial biomass using either 1M of CH(3)COOH, HNO(3) or H(2)SO(4) with 90% recovery. TEM and FTIR suggested the involvement of amine, carboxyl, hydroxyl and phosphate groups during the biosorption of Cr(III) onto the cell surface of A. haemolyticus. A. haemolyticus was also capable to remove 79.87 mg g(-1) Cr(III) (around 22.75%) from raw leather tanning wastewater. This study demonstrates the potential of using A. haemolyticus as biosorbent to remove Cr(III) from both synthetic and industrial wastewater. PMID:22398363

  20. Epidemiology of Carbapenemase-Producing Enterobacteriaceae and Acinetobacter baumannii in Mediterranean Countries

    Nassima Djahmi

    2014-01-01

    Full Text Available The emergence and global spread of carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii are of great concern to health services worldwide. These β-lactamases hydrolyse almost all β-lactams, are plasmid-encoded, and are easily transferable among bacterial species. They are mostly of the KPC, VIM, IMP, NDM, and OXA-48 types. Their current extensive spread worldwide in Enterobacteriaceae is an important source of concern. Infections caused by these bacteria have limited treatment options and have been associated with high mortality rates. Carbapenemase producers are mainly identified among Klebsiella pneumoniae, Escherichia coli, and A. baumannii and still mostly in hospital settings and rarely in the community. The Mediterranean region is of interest due to a great diversity and population mixing. The prevalence of carbapenemases is particularly high, with this area constituting one of the most important reservoirs. The types of carbapenemase vary among countries, partially depending on the population exchange relationship between the regions and the possible reservoirs of each carbapenemase. This review described the epidemiology of carbapenemases produced by enterobacteria and A. baumannii in this part of the world highlighting the worrisome situation and the need to screen and detect these enzymes to prevent and control their dissemination.

  1. Carbapenem-resistant Acinetobacter baumannii acquired before liver transplantation: Impact on recipient outcomes.

    Freire, Maristela Pinheiro; Pierrotti, Ligia Câmera; Oshiro, Isabel Cristina Villela Soares; Bonazzi, Patrícia Rodrigues; Oliveira, Larissa Marques de; Machado, Anna Silva; Van Der Heijden, Inneke Marie; Rossi, Flavia; Costa, Silvia Figueiredo; D'Albuquerque, Luiz Augusto Carneiro; Abdala, Edson

    2016-05-01

    Infection with carbapenem-resistant Acinetobacter baumannii (CRAB) after liver transplantation (LT) is associated with high mortality. This study aimed to identify risk factors for post-LT CRAB infection, as well as to evaluate the impact of pre-LT CRAB acquisition on the incidence of post-LT CRAB infection. This was a prospective cohort study of all patients undergoing LT at our facility between October 2009 and October 2011. Surveillance cultures (SCs) were collected immediately before LT and weekly thereafter, until discharge. We analyzed 196 patients who were submitted to 222 LTs. CRAB was identified in 105 (53.6%); 24 (22.9%) of these patients were found to have acquired CRAB before LT, and 85 (81.0%) tested positive on SCs. Post-LT CRAB infection occurred in 56 (28.6%), the most common site being the surgical wound. Multivariate analysis showed that the risk factors for developing CRAB infection were prolonged cold ischemia, post-LT dialysis, LT due to fulminant hepatitis, and pre-LT CRAB acquisition with pre-LT CRAB acquisition showing a considerable trend toward significance (P = 0.06). Among the recipients with CRAB infection, 60-day mortality was 46.4%, significantly higher than among those without (P recipient survival. Liver Transplantation 22 615-626 2016 AASLD. PMID:26684547

  2. Safety and effectiveness of colistin compared with tobramycin for multi-drug resistant Acinetobacter baumannii infections

    Cohen Karen

    2009-03-01

    Full Text Available Abstract Background Nosocomial infections due to multi-drug resistant Acinetobacter baumannii are often treated with colistin, but there are few data comparing its safety and efficacy with other antimicrobials. Methods A retrospective cohort study of patients treated with colistin or tobramycin for A. baumannii infections in intensive care units (ICUs at Groote Schuur hospital. Colistin was used for A. baumannii isolates which were resistant to all other available antimicrobials. In the tobramycin group, 53% of the isolates were only susceptible to tobramycin and colistin. We assessed ICU mortality, nephrotoxicity and time to the first negative culture. Results 32 patients, with similar admission APACHE scores and serum creatinine, were treated with each antimicrobial. There were no significant differences between the colistin and tobramycin groups in ICU mortality (p = 0.54, nephrotoxicity (p = 0.67, change in creatinine from baseline to highest subsequent value (p = 0.11 and time to microbiological clearance (p = 0.75. The hazard ratio for total in-hospital survival in patients treated with colistin compared to tobramycin was 0.43 (95% CI 0.19 to 0.99. Conclusion Our study suggests that colistin and tobramycin have similar risks of nephrotoxicity and are equally efficacious. Colistin is an acceptable antibiotic for the treatment of A. baumanii infections when the organism is resistant to other available antimicrobials.

  3. Functional Exposed Amino Acids of BauA as Potential Immunogen Against Acinetobacter baumannii.

    Sefid, Fatemeh; Rasooli, Iraj; Jahangiri, Abolfazl; Bazmara, Hadise

    2015-06-01

    Multidrug-resistant Acinetobacter baumannii is recognized to be among the most difficult antimicrobial-resistant gram negative bacilli to control and treat. One of the major challenges that the pathogenic bacteria face in their host is the scarcity of freely available iron. To survive under such conditions, bacteria express new proteins on their outer membrane and also secrete iron chelators called siderophores. Antibodies directed against these proteins associated with iron uptake exert a bacteriostatic or bactericidal effect against A. baumanii in vitro, by blocking siderophore mediated iron uptake pathways. Attempts should be made to discover peptides that could mimic protein epitopes and possess the same immunogenicity as the whole protein. Subsequently, theoretical methods for epitope prediction have been developed leading to synthesis of such peptides that are important for development of immunodiagnostic tests and vaccines. The present study was designed to in silico resolving the major obstacles in the control or in prevention of the diseases caused by A. baumannii. We exploited bioinformatic tools to better understand and characterize the Baumannii acinetobactin utilization structure of A. baumannii and select appropriate regions as effective B cell epitopes. In conclusion, amino acids 26-191 of cork domain and 321-635 of part of the barrel domain including L4-L9, were selected as vaccine candidates. These two regions contain functional exposed amino acids with higher score of B cell epitopes properties. Majority of amino acids are hydrophilic, flexible, accessible, and favorable for B cells from secondary structure point of view. PMID:25840681

  4. Combination therapy with polymyxin B and netropsin against clinical isolates of multidrug-resistant Acinetobacter baumannii.

    Chung, Joon-Hui; Bhat, Abhayprasad; Kim, Chang-Jin; Yong, Dongeun; Ryu, Choong-Min

    2016-01-01

    Polymyxins are last-resort antibiotics for treating infections of Gram-negative bacteria. The recent emergence of polymyxin-resistant bacteria, however, urgently demands clinical optimisation of polymyxin use to minimise further evolution of resistance. In this study we developed a novel combination therapy using minimal concentrations of polymyxin B. After large-scale screening of Streptomyces secondary metabolites, we identified a reliable polymixin synergist and confirmed as netropsin using high-pressure liquid chromatography, nuclear magnetic resonance, and mass spectrometry followed by in vitro assays using various Gram-negative pathogenic bacteria. To evaluate the effectiveness of combining polymixin B and netropsin in vivo, we performed survival analysis on greater wax moth Galleria mellonella infected with colistin-resistant clinical Acinetobacter baumannii isolates as well as Escherichia coli, Shigella flexineri, Salmonella typhimuruim, and Pseudomonas aeruginosa. The survival of infected G. mellonella was significantly higher when treated with polymyxin B and netropsin in combination than when treated with polymyxin B or netropsin alone. We propose a netropsin combination therapy that minimises the use of polymyxin B when treating infections with multidrug resistant Gram-negative bacteria. PMID:27306928

  5. Candida spp. airway colonization: A potential risk factor for Acinetobacter baumannii ventilator-associated pneumonia.

    Tan, Xiaojiang; Zhu, Song; Yan, Dongxing; Chen, Weiping; Chen, Ruilan; Zou, Jian; Yan, Jingdong; Zhang, Xiangdong; Farmakiotis, Dimitrios; Mylonakis, Eleftherios

    2016-08-01

    This retrospective study was conducted to identify potential risk factors for Acinetobacter baumannii (A. baumannii) ventilator-associated pneumonia (VAP) and evaluate the association between Candida spp. airway colonization and A. baumannii VAP. Intensive care unit (ICU) patients who were on mechanical ventilation (MV) for ≥48 hours were divided into the following groups: patients with and without Candida spp. airway colonization; colonized patients receiving antifungal treatment or not; patients with A. baumannii VAP and those without VAP. Logistic regression analysis and propensity score matching were used to identify factors independently associated with A. baumannii VAP. Among 618 eligible patients, 264 (43%) had Candida spp. airway colonization and 114 (18%) developed A. baumannii VAP. Along with MV for ≥7 days (adjusted odds ratio [aOR] 8.9, 95% confidence intervals [95% CI] 4.9-15.8) and presence of a central venous catheter (aOR 3.2, 95% CI 1.1-9), Candida spp. airway colonization (aOR 2.6, 95% CI 1.6-4.3) was identified as an independent risk factor for A. baumannii VAP. Patients with Candida spp. airway colonization were more likely to develop A. baumannii VAP than non-colonized patients (23% vs 15%, P=.01 and 34% vs. 15%, Pmechanical ventilation for at least 48 hours. Candida spp. airway colonization was an independent risk factor for subsequent A. baumannii VAP. PMID:27001670

  6. The induction and identification of novel Colistin resistance mutations in Acinetobacter baumannii and their implications.

    Thi Khanh Nhu, Nguyen; Riordan, David W; Do Hoang Nhu, Tran; Thanh, Duy Pham; Thwaites, Guy; Huong Lan, Nguyen Phu; Wren, Brendan W; Baker, Stephen; Stabler, Richard A

    2016-01-01

    Acinetobacter baumannii is a significant cause of opportunistic hospital acquired infection and has been identified as an important emerging infection due to its high levels of antimicrobial resistance. Multidrug resistant A. baumannii has risen rapidly in Vietnam, where colistin is becoming the drug of last resort for many infections. In this study we generated spontaneous colistin resistant progeny (up to >256 μg/μl) from four colistin susceptible Vietnamese isolates and one susceptible reference strain (MIC <1.5 μg/μl). Whole genome sequencing was used to identify single nucleotide mutations that could be attributed to the reduced colistin susceptibility. We identified six lpxACD and three pmrB mutations, the majority of which were novel. In addition, we identified further mutations in six A. baumannii genes (vacJ, pldA, ttg2C, pheS and conserved hypothetical protein) that we hypothesise have a role in reduced colistin susceptibility. This study has identified additional mutations that may be associated with colistin resistance through novel resistance mechanisms. Our work further demonstrates how rapidly A. baumannii can generate resistance to a last resort antimicrobial and highlights the need for improved surveillance to identified A. baumannii with an extensive drug resistance profile. PMID:27329501

  7. Activity of Gallium Meso- and Protoporphyrin IX against Biofilms of Multidrug-Resistant Acinetobacter baumannii Isolates.

    Chang, David; Garcia, Rebecca A; Akers, Kevin S; Mende, Katrin; Murray, Clinton K; Wenke, Joseph C; Sanchez, Carlos J

    2016-01-01

    Acinetobacter baumannii is a challenging pathogen due to antimicrobial resistance and biofilm development. The role of iron in bacterial physiology has prompted the evaluation of iron-modulation as an antimicrobial strategy. The non-reducible iron analog gallium(III) nitrate, Ga(NO₃)₃, has been shown to inhibit A. baumannii planktonic growth; however, utilization of heme-iron by clinical isolates has been associated with development of tolerance. These observations prompted the evaluation of iron-heme sources on planktonic and biofilm growth, as well as antimicrobial activities of gallium meso- and protoporphyrin IX (Ga-MPIX and Ga-PPIX), metal heme derivatives against planktonic and biofilm bacteria of multidrug-resistant (MDR) clinical isolates of A. baumannii in vitro. Ga(NO₃)₃ was moderately effective at reducing planktonic bacteria (64 to 128 µM) with little activity against biofilms (≥512 µM). In contrast, Ga-MPIX and Ga-PPIX were highly active against planktonic bacteria (0.25 to 8 µM). Cytotoxic effects in human fibroblasts were observed following exposure to concentrations exceeding 128 µM of Ga-MPIX and Ga-PPIX. We observed that the gallium metal heme conjugates were more active against planktonic and biofilm bacteria, possibly due to utilization of heme-iron as demonstrated by the enhanced effects on bacterial growth and biofilm formation. PMID:26999163

  8. Endogenous hydrogen peroxide increases biofilm formation by inducing exopolysaccharide production in Acinetobacter oleivorans DR1.

    Jang, In-Ae; Kim, Jisun; Park, Woojun

    2016-01-01

    In this study, we investigated differentially expressed proteins in Acinetobacter oleivorans cells during planktonic and biofilm growth by using 2-dimensional gel electrophoresis combined with matrix-assisted laser desorption time-of-flight mass spectrometry. We focused on the role of oxidative stress resistance during biofilm formation using mutants defective in alkyl hydroperoxide reductase (AhpC) because its production in aged biofilms was enhanced compared to that in planktonic cells. Results obtained using an ahpC promoter-gfp reporter vector showed that aged biofilms expressed higher ahpC levels than planktonic cells at 48 h. However, at 24 h, ahpC expression was higher in planktonic cells than in biofilms. Deletion of ahpC led to a severe growth defect in rich media that was not observed in minimal media and promoted early biofilm formation through increased production of exopolysaccharide (EPS) and EPS gene expression. Increased endogenous H2O2 production in the ahpC mutant in rich media enhanced biofilm formation, and this enhancement was not observed in the presence of antioxidants. Exogenous addition of H2O2 promoted biofilm formation in wild type cells, which suggested that biofilm development is linked to defense against H2O2. Collectively, our data showed that EPS production caused by H2O2 stress enhances biofilm formation in A. oleivorans. PMID:26884212

  9. Carbapenem-resistant Acinetobacter ventilator-associated pneumonia: Clinical characteristics and outcome

    Mohan Gurjar

    2013-01-01

    Full Text Available Objective: To study the clinical characteristics and 28-days mortality in patients with ventilator-associated pneumonia (VAP due to carbapenem-resistant Acinetobacter (CRA. Design: Retrospective, observational, cohort study. Setting: Intensive care unit (ICU of a university hospital. Materials and Methods: Microbiologically confirmed VAP due to CRA infection. Intervention: None. Results: Out of 87 patients with VAP due to CRA, 60 (69% were male; whose median age was 51 years; 73 (84% patients were medical; 26 (30% had history of hospitalization in last 3 months; median acute physiology and chronic health evaluation (APACHE II was 15 and median SOFA 9 at admission; primary reason for ICU admission was respiratory failure (34%; 46 (53% patients had more than 2 organ failure at ICU admission; median length of ICU stay was 19 days; 66 (76% patients need vasoactive agents during ICU stay, whereas 55 (63% patients had renal failure; median duration of mechanical ventilation was 17 days; 22 (25% patients had acute respiratory distress syndrome (ARDS during ICU stay; 72 (83% patients had exposure to carbapenem before inclusion in the study; 33 (38% patients had same organism at other sites. In the follow-up, 47 (54% patient survived at 28 days after having VAP; whereas only 40 (46% patients were discharged from the hospital. Conclusions: CRA-VAP has high crude mortality. Advanced age; severity of illness and presence of pneumonia at ICU admission; and presence of shock, ARDS and renal failure have impact on outcome in these patients.

  10. 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

    M. S. Ramírez; Bello, H.; G. González Rocha; C. Márquez; Centrón, D.

    2010-01-01

    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 a...

  11. 101株鲍曼不动杆菌的耐药性分析%Analysis of drug resistance of acinetobacter baumannii

    王仲书; 李玉梅; 王灿灿

    2011-01-01

    目的 了解鲍曼不动杆菌的临床分布及其对常用抗生素的耐药状况,为有效的临床治疗和医院感染控制提供实验室依据.方法 对2008年4月~2009年6月间某院分离出的101株鲍曼不动杆菌通过微量稀释法进行MIC测定.结果101株鲍曼不动杆菌大多分离自痰液,主要来自于ICU病房.鲍曼不动杆菌对复方新诺明耐药率最高,为91%,依次是环丙沙星89%,庆大霉素86%、头孢噻肟86%等.结论:我院鲍曼不动杆菌耐药情况严重,治疗首选碳青霉烯类抗生素,其次可选用替卡西林/克拉维酸、头孢哌酮/舒巴坦.%Objective To investigate the distribution and drug resistance of Acinetobacter baumanii. Methods The minimum inhibitory concentrations (MIC) of 101 acinetobacter baumannii isolated were measured by microdilution method. Results 101 Acinetobacter baummanii were mainly isolated from ICU, and most of them were from sputum. Antimicrobial susceptibility tests showed the resistant rate of Acinetobacter baumannii to Trimethoprim-Sulfamethoxazole was the highest (91%), folio wed by gentamicin (86%), cefotaxime (86%). Conclusion The drug resistance of Acinetobacter baummanii is serious. Carbapenem is the preferred antibacterial therapy for Acinetobacter baumannii.

  12. 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

    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...... 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...

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

    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

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

    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

    2016-09-01

    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 study, a total of 112 bloodstream isolates of carbapenem-resistant Acinetobacter spp. were collected from 11 hospitals across Turkey and Azerbaijan. The identification of Acinetobacter spp. using conventional and sensitivity tests was performed by standard criteria. Multiplex polymerase chain reaction (PCR) was used to detect OXA carbapenemase-encoding genes (bla OXA-23-like, bla OXA-24-like, bla OXA-51-like, and bla OXA-58-like). Pulsed-field gel electrophoresis (PFGE) typing was used to investigate genetic diversity. The bla OXA-51-like gene was present in all 112 isolates, 75 (67 %) carried bla OXA-23-like, 7 (6.2 %) carried bla OXA-58-like genes, and 5 (4.5 %) carried bla OXA-24-like genes. With a 90 % similarity cut-off value, 15 clones and eight unique isolates were identified. The largest clone was cluster D, with six subtypes. Isolates from clusters D and I were widely spread in seven different geographical regions throughout Turkey. However, F cluster was found in the northern and eastern regions of Turkey. EU clone I was grouped within J cluster with three isolates found in Antalya, Istanbul, and Erzurum. EU clone II was grouped in the U cluster with 15 isolates and found in Kayseri and Diyarbakır. The bla OXA-24-like gene in carbapenemases was identified rarely in Turkey and has been reported for the first time from Azerbaijan. Furthermore, this is the first multicenter study in Turkey and Azerbaijan to identify several major clusters belonging to European clones I and II of A. baumannii. PMID:27259712

  15. Uso tradicional y actual de spirulina sp. (Arthrospira sp.)

    Liliana Ramírez- Moreno; Roxana Olvera-Ramírez

    2006-01-01

    Spirulina sp. (Arthrospira sp.) es una cianobacteria filamentosa no diferenciada, habitante de lagos alcalinos, que se cultiva para consumo humano debido a su contenido nutricional. En México, el consumo de esta cianobacteria se remonta a tiempos prehispánicos, cuando era conocida como tecuitlatl, siendo conocida como dihé por las tribus nativas de la región del lago de Chad, en África. En los últimos años se le han atribuido diversos efectos positivos en el tratamiento de algunos tipos de al...

  16. Potent in vitro antibacterial activity of DS-8587, a novel broad-spectrum quinolone, against Acinetobacter baumannii.

    Higuchi, Saito; Onodera, Yoshikuni; Chiba, Megumi; Hoshino, Kazuki; Gotoh, Naomasa

    2013-04-01

    We investigated the in vitro activity of DS-8587, a novel fluoroquinolone, against Acinetobacter baumannii. The MICs of DS-8587 against clinical isolates and its inhibitory activity against target enzymes were superior to those of ciprofloxacin and levofloxacin. Furthermore, the antibacterial activity of DS-8587 was less affected by adeA/adeB/adeC or abeM efflux pumps than was that of ciprofloxacin and the frequency of single-step mutations with DS-8587 was lower than that with ciprofloxacin. DS-8587 might be an effective agent against A. baumannii infection. PMID:23380726

  17. Fulminating septicemia due to persistent pan-resistant community-acquired metallo-β-lactamase (IMP-1-positive Acinetobacter baumannii

    Nilima V Telang

    2011-01-01

    Full Text Available Acinetobacter baumannii is considered as an emerging nosocomial pathogen and is renowned for its multi-drug resistance. We report a case of community-acquired pan-resistant A. baumannii caused fulminating septicemia. The treatment failure led to death. The A. baumannii strain isolated from blood, pus, urine and tracheal aspirate was confirmed by 16S r-RNA sequence homology and found positive for metallo-β-lactamase IMP-1, and was found to be a strong biofilm producer. The isolate was only susceptible (moderately to colistin.

  18. Colistin Resistance in a Clinical Acinetobacter baumannii Strain Appearing after Colistin Treatment: Effect on Virulence and Bacterial Fitness

    López-Rojas, Rafael; McConnell, Michael J.; Jiménez-Mejías, Manuel Enrique; Domínguez-Herrera, Juan; Fernández-Cuenca, Felipe; Pachón, Jerónimo

    2013-01-01

    The fitness and virulence costs associated with the clinical acquisition of colistin resistance by Acinetobacter baumannii were evaluated. The growth of strain CR17 (colistin resistant) was less than that of strain CS01 (colistin susceptible) when the strains were grown in competition (72-h competition index, 0.008). In a murine sepsis model, CS01 and CR17 reached spleen concentrations when coinfecting of 9.31 and 6.97 log10 CFU/g, respectively, with an in vivo competition index of 0.016. Mor...

  19. Plasmid-Encoded Tetracycline Efflux Pump Protein Alters Bacterial Stress Responses and Ecological Fitness of Acinetobacter oleivorans

    Hong, Hyerim; Jung, Jaejoon; Park, Woojun

    2014-01-01

    Acquisition of the extracellular tetracycline (TC) resistance plasmid pAST2 affected host gene expression and phenotype in the oil-degrading soil bacterium, Acinetobacter oleivorans DR1. Whole-transcriptome profiling of DR1 cells harboring pAST2 revealed that all the plasmid genes were highly expressed under TC conditions, and the expression levels of many host chromosomal genes were modulated by the presence of pAST2. The host energy burden imposed by replication of pAST2 led to (i) lowered ...

  20. Draft Genome Sequence of a Multidrug-Resistant blaNDM-1-Producing Acinetobacter soli Isolate in China

    Chen, Yan; Yan, Zhengsong; Wang, Miaojuan; Zheng, Xia; Lu, Yun; Lin, Shaohua

    2014-01-01

    Acinetobacter spp. are one of the most prevalent opportunistic pathogens causing nosocomial infections and have become a major clinical and public health threat. In this study, we presented the first draft genome sequence of A. soli TCM341, a multidrug resistant isolate that carried the blaNDM-1 gene in China. Genome sequencing of A. soli TCM341 was carried out in Illumina Hiseq 2000 next-generation sequencer. The data obtained revealed 74 contigs with genome size of 3.49 Mb and G+C content o...

  1. Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal

    Goel Vikas; Kapil Arti

    2001-01-01

    Abstract Background Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10-18M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores. Results/ Discussion Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, e...

  2. Outbreak of carbapenem-resistant Acinetobacter baumannii in the intensive care unit: a multi-level strategic management approach.

    Molter, G; Seifert, H; Mandraka, F; Kasper, G; Weidmann, B; Hornei, B; Öhler, M; Schwimmbeck, P; Kröschel, P; Higgins, P G; Reuter, S

    2016-02-01

    An outbreak of carbapenem-resistant Acinetobacter baumannii (CRAb) occurred in an interdisciplinary intensive care unit, affecting 10 patients. Within hours of recognition of the spread of CRAb an intervention team was instituted for collection of available data, decision-making, communication and monitoring of all interventions performed, including cohorting, temporary stop of admissions, staff education, and enforcement of infection control measures. An area was defined for cohortation of patients colonized with CRAb, with a separate nursing team and a second set of mobile equipment. New transmissions were no longer observed after only four days into the institution of enhanced infection control measures. PMID:26778130

  3. Update on Acinetobacter species: mechanisms of antimicrobial resistance and contemporary in vitro activity of minocycline and other treatment options.

    Castanheira, Mariana; Mendes, Rodrigo E; Jones, Ronald N

    2014-12-01

    Among Acinetobacter species, A. baumannii and other closely related species are commonly implicated in nosocomial infections. These organisms are usually multidrug resistant (MDR), and therapeutic options to treat A. baumannii infections are very limited. Clinicians have been resorting to older antimicrobial agents to treat infections caused by MDR A. baumannii, and some of these agents have documented toxicity and/or are not optimized for the infection type to be treated. Recent clinical experience supported by antimicrobial susceptibility data suggests that minocycline has greater activity than other tetracyclines and glycylcyclines against various MDR pathogens that have limited therapeutic options available, including Acinetobacter species. An intravenous formulation of minocycline has recently become available for clinical use, and in contrast to most older tetracyclines, minocycline has high activity against Acinetobacter species. In this report, we summarized some of the characteristics of the tetracycline class, and quantified the minocycline activity against contemporary (2007-2011) isolates and its potential therapeutic role against a collection of 5477 A. baumannii and other relevant gram-negative organisms when compared directly with tetracycline, doxycycline, and other broad-spectrum antimicrobial agents. Acinetobacter baumannii strains were highly resistant to all agents tested, with the exception of minocycline (79.1% susceptible) and colistin (98.8% susceptible). Minocycline (minimum inhibitory concentration that inhibits 50% and 90% of the isolates [MIC(50/90)]: 1/8 µg/mL) displayed greater activity than doxycycline (MIC(50/90): 2/>8 µg/mL) and tetracycline hydrochloride (HCL) (only 30.2% susceptible) against A. baumannii isolates, and was significantly more active than other tetracyclines against Burkholderia cepacia, Escherichia coli, Serratia marcescens, and Stenotrophomonas maltophilia isolates. In vitro susceptibility testing using

  4. The Response Regulator BfmR Is a Potential Drug Target for Acinetobacter baumannii.

    Russo, Thomas A; Manohar, Akshay; Beanan, Janet M; Olson, Ruth; MacDonald, Ulrike; Graham, Jessica; Umland, Timothy C

    2016-01-01

    Identification and validation is the first phase of target-based antimicrobial development. BfmR (RstA), a response regulator in a two-component signal transduction system (TCS) in Acinetobacter baumannii, is an intriguing potential antimicrobial target. A unique characteristic of BfmR is that its inhibition would have the dual benefit of significantly decreasing in vivo survival and increasing sensitivity to selected antimicrobials. Studies on the clinically relevant strain AB307-0294 have shown BfmR to be essential in vivo. Here, we demonstrate that this phenotype in strains AB307-0294 and AB908 is mediated, in part, by enabling growth in human ascites fluid and serum. Further, BfmR conferred resistance to complement-mediated bactericidal activity that was independent of capsular polysaccharide. Importantly, BfmR also increased resistance to the clinically important antimicrobials meropenem and colistin. BfmR was highly conserved among A. baumannii strains. The crystal structure of the receiver domain of BfmR was determined, lending insight into putative ligand binding sites. This enabled an in silico ligand binding analysis and a blind docking strategy to assess use as a potential druggable target. Predicted binding hot spots exist at the homodimer interface and the phosphorylation site. These data support pursuing the next step in the development process, which includes determining the degree of inhibition needed to impact growth/survival and the development a BfmR activity assay amenable to high-throughput screening for the identification of inhibitors. Such agents would represent a new class of antimicrobials active against A. baumannii which could be active against other Gram-negative bacilli that possess a TCS with shared homology. IMPORTANCE Increasing antibiotic resistance in bacteria, particularly Gram-negative bacilli, has significantly affected the ability of physicians to treat infections, with resultant increased morbidity, mortality, and health

  5. Synergistic effects of sulbactam in multi-drug-resistant Acinetobacter baumannii

    Fatih Temocin

    2015-12-01

    Full Text Available Abstract Acinetobacter baumannii is a frequently isolated etiologic agent of nosocomial infections, especially in intensive care units. With the increase in multi-drug resistance of A. baumannii isolates, finding appropriate treatment alternatives for infections caused by these bacteria has become more difficult, and available alternate treatments include the use of older antibiotics such as colistin or a combination of antibiotics. The current study aimed to evaluate the in vitro efficacy of various antibiotic combinations against multi-drug resistant A. baumannii strains. Thirty multi-drug and carbapenem resistant A. baumannii strains isolated at the Ankara Training and Research Hospital between June 2011 and June 2012 were used in the study. Antibiotic susceptibility tests and species-level identification were performed using conventional methods and the VITEK 2 system. The effects of meropenem, ciprofloxacin, amikacin, tigecycline, and colistin alone and in combination with sulbactam against the isolates were studied using Etest (bioMérieux in Mueller-Hinton agar medium. Fractional inhibitory concentration index (FIC was used to determine the efficacy of the various combinations. While all combinations showed a predominant indifferent effect, a synergistic effect was also observed in 4 of the 5 combinations. Synergy was demonstrated in 43% of the isolates with the meropenem-sulbactam combination, in 27% of the isolates with tigecycline-sulbactam, and in 17% of the isolates with colistin-sulbactam and amikacin-sulbactam. No synergy was detected with the sulbactam-ciprofloxacin combination and antagonism was detected only in the sulbactam-colistin combination (6.66% of the isolates. Antibiotic combinations can be used as an alternative treatment approach in multi-drug resistant A. baumannii infections.

  6. Molecular mechanism involved in the response to hydrogen peroxide stress in Acinetobacter oleivorans DR1.

    Kim, Jisun; Cho, Youjung; Jang, In-Ae; Park, Woojun

    2015-12-01

    Two-dimensional gel electrophoresis was conducted to investigate the effect of H2O2 on whole protein expression in Acinetobacter oleivorans DR1. Functional classification of 13 upregulated proteins using MALDI-TOF mass spectrometry showed relationships with oxidative stress, energy production and conversion, nucleotide and amino acid metabolism, membrane-related, ion transport, and chaperone-related functions. Alignment of OxyR-binding regions from Pseudomonas aeruginosa and Escherichia coli with promoters of identified proteins revealed that only ahpC, ahpF, and trxB (thioredoxin-disulfide reductase) genes, along with a newly found oprC (putative outer membrane receptor protein) gene, have OxyR-binding sites. The oxyR and ahpC mutants were more sensitive to H2O2 and showed growth defects in both nutritional and n-hexadecane-amended media. Four catalases present in the genome of A. oleivorans DR1 were not detected, which led us to confirm the expression and activity of those catalases in the presence of H2O2. The expression patterns of the four catalase genes differed at different concentrations of H2O2. Interestingly, the promoters of both known OxyR-controlled katG gene (AOLE_17390) and putative small catalase gene (AOLE_09800) have OxyR-binding sites. Gel-shift assay confirmed OxyR binding to the promoter regions of newly identified OxyR-controlled genes encoding OprC and a putative catalase. Hierarchical expression and OxyR-binding of several OxyR-controlled genes suggested that concentration is an important factor in inducing the set of genes under H2O2 stress. PMID:26298700

  7. Infections caused by Acinetobacter baumannii in recipients of hematopoietic stem cell transplantation

    Khalid Ahmed Al-Anazi

    2014-07-01

    Full Text Available Acinetobacter baumannii (A. baumannii is a Gram-negative, strictly aerobic, non-fermentative coccobacillus which is widely distributed in nature. Recently, it has emerged as a major cause of health care-associated infections in addition to its capacity to cause community acquired infections. Risk factors for A. baumannii infections and bacteremia in recipients of hematopoietic stem cell transplantation include: severe underlying illness such as hematological malignancy, prolonged use of broad-spectrum antibiotics, invasive instrumentation such as central venous catheters or endotracheal intubation, colonization of respiratory, gastrointestinal or urinary tracts in addition to severe immunosuppression caused by using corticosteroids for treating graft versus host disease. The organism causes a wide spectrum of clinical manifestations, but serious complications such as bacteremia, septic shock, ventilator-associated pneumonia, extensive soft tissue necrosis and rapidly progressive systemic infections that ultimately lead to multiorgan failure and death are prone to occur in severely immunocompromised hosts. The organism is usually resistant to many antimicrobials including penicillins, cephalosporins, trimethoprim-sulfamethoxazole, almost all flouroquinolones and most of the aminoglycosides. The recently increasing resistance to carbapenems, colistin and polymyxins is alarming. Additionally, there are geographic variations in the resistance patterns and several globally and regionally resistant strains have already been described. Successful management of A.baumannii infections depends upon appropriate utilization of antibiotics and strict application of preventive and infection control measures. In uncomplicated infections, the use of a single active beta-lactam may be justified, while definitive treatment of complicated infections in critically ill individuals may require drug combinations such as colistin and rifampicin or colistin and

  8. Characterising the Transmission Dynamics of Acinetobacter baumannii in Intensive Care Units Using Hidden Markov Models.

    Doan, Tan N; Kong, David C M; Marshall, Caroline; Kirkpatrick, Carl M J; McBryde, Emma S

    2015-01-01

    Little is known about the transmission dynamics of Acinetobacter baumannii in hospitals, despite such information being critical for designing effective infection control measures. In the absence of comprehensive epidemiological data, mathematical modelling is an attractive approach to understanding transmission process. The statistical challenge in estimating transmission parameters from infection data arises from the fact that most patients are colonised asymptomatically and therefore the transmission process is not fully observed. Hidden Markov models (HMMs) can overcome this problem. We developed a continuous-time structured HMM to characterise the transmission dynamics, and to quantify the relative importance of different acquisition sources of A. baumannii in intensive care units (ICUs) in three hospitals in Melbourne, Australia. The hidden states were the total number of patients colonised with A. baumannii (both detected and undetected). The model input was monthly incidence data of the number of detected colonised patients (observations). A Bayesian framework with Markov chain Monte Carlo algorithm was used for parameter estimations. We estimated that 96-98% of acquisition in Hospital 1 and 3 was due to cross-transmission between patients; whereas most colonisation in Hospital 2 was due to other sources (sporadic acquisition). On average, it takes 20 and 31 days for each susceptible individual in Hospital 1 and Hospital 3 to become colonised as a result of cross-transmission, respectively; whereas it takes 17 days to observe one new colonisation from sporadic acquisition in Hospital 2. The basic reproduction ratio (R0) for Hospital 1, 2 and 3 was 1.5, 0.02 and 1.6, respectively. Our study is the first to characterise the transmission dynamics of A. baumannii using mathematical modelling. We showed that HMMs can be applied to sparse hospital infection data to estimate transmission parameters despite unobserved events and imperfect detection of the organism

  9. Characterising the Transmission Dynamics of Acinetobacter baumannii in Intensive Care Units Using Hidden Markov Models.

    Tan N Doan

    Full Text Available Little is known about the transmission dynamics of Acinetobacter baumannii in hospitals, despite such information being critical for designing effective infection control measures. In the absence of comprehensive epidemiological data, mathematical modelling is an attractive approach to understanding transmission process. The statistical challenge in estimating transmission parameters from infection data arises from the fact that most patients are colonised asymptomatically and therefore the transmission process is not fully observed. Hidden Markov models (HMMs can overcome this problem. We developed a continuous-time structured HMM to characterise the transmission dynamics, and to quantify the relative importance of different acquisition sources of A. baumannii in intensive care units (ICUs in three hospitals in Melbourne, Australia. The hidden states were the total number of patients colonised with A. baumannii (both detected and undetected. The model input was monthly incidence data of the number of detected colonised patients (observations. A Bayesian framework with Markov chain Monte Carlo algorithm was used for parameter estimations. We estimated that 96-98% of acquisition in Hospital 1 and 3 was due to cross-transmission between patients; whereas most colonisation in Hospital 2 was due to other sources (sporadic acquisition. On average, it takes 20 and 31 days for each susceptible individual in Hospital 1 and Hospital 3 to become colonised as a result of cross-transmission, respectively; whereas it takes 17 days to observe one new colonisation from sporadic acquisition in Hospital 2. The basic reproduction ratio (R0 for Hospital 1, 2 and 3 was 1.5, 0.02 and 1.6, respectively. Our study is the first to characterise the transmission dynamics of A. baumannii using mathematical modelling. We showed that HMMs can be applied to sparse hospital infection data to estimate transmission parameters despite unobserved events and imperfect detection of

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

    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. PMID:27045768

  11. Identification of New Delhi metallo-β-lactamase 1 in Acinetobacter lwoffii of food animal origin.

    Yang Wang

    Full Text Available BACKGROUND: To investigate the presence of metallo-β-lactamase (MBL genes and the genetic environment of the New Delhi metallo-β-lactamase gene bla(NDM-1 in bacteria of food animal origin. METHODOLOGY/PRINCIPAL FINDINGS: Gram-negative bacteria with low susceptibility to imipenem (MIC>8 µg/mL were isolated from swab samples collected from 15 animal farms and one slaughterhouse in eastern China. These bacteria were selected for phenotypic and molecular detection of known MBL genes and antimicrobial susceptibility testing. For the bla(NDM-1 positive isolate, conjugation and transformation experiments were carried out to assess plasmid transfer. Southern blotting was conducted to localize the bla(NDM-1 genes, and DNA sequencing was performed to determine the sequences of bla(NDM-1 and the flanking genes. In total, nine gram-negative bacteria of four different species presented a MBL phenotype. bla(NDM-1 was identified on a mobile plasmid named pAL-01 in an Acinetobacter lwoffii isolate of chicken origin. Transfer of pAL-01 from this isolate to E. coli J53 and JM109 resulted in resistance to multiple β-lactams. Sequence analysis revealed that the bla(NDM-1 gene is attached to an intact insertion element ISAba125, whose right inverted repeat (IR-R overlaps with the promoter sequence of bla(NDM-1. Thus, insertion of ISAba125 likely enhances the expression of bla(NDM-1. CONCLUSION: The identification of a bla(NDM-1- carrying strain of A. lwoffii in chickens suggests the potential for zoonotic transmission of bla(NDM-1 and has important implications for food safety.

  12. The Prevalence of ESBL Isolates of Acinetobacter baumannii Using Pulsed-Field Gel Electrophoresis

    Parviz Mohajeri

    2014-12-01

    Full Text Available Background: Antibiotics such as fluoroquinolones are used for treating infections caused by Gram-negative bacteria, including Acinetobacter baumannii strains some time have extended-spectrum β-lactamase (ESBL, but ESBL production is rather rare. Resistance to fluoroquinolones antibiotics is mediated by lactamases and other mechanisms of resistance. The aim of the present study was to investigate of the prevalence of ESBL production and clonal relatedness of A. baumannii in Iran. Materials and Methods: A. baumannii isolates identified from patients at hospitals in Kermanshah, Iran, were studied. The double disk method was used for detection of ESBL production. The susceptibility to different antibiotics was determined by the disk diffusion method (CLSI. Clonal relatedness was determined by pulsed-field gel electrophoresis (PFGE and processed by Bionumerics 7.0 software. Statistical analyses were performed using SPSS-16.0. Results: This study showed high prevalence of resistance to ampicillin and cefpodoxim (98.1 and 92.3%. Fifty-two of the 84 isolates were identified as ESBL producers. Only colistin and tigecycline remained active against all isolates tested. The PFGE identified eight distinct pulsotypes: A (N=9, B (N=10, C (N=2, D (N=5, E (N=9, F (N=15, G (N=1 and H (N=1. The PFGE profiles A, B and F were believed to be endemic (specially clone F that was dominant across different wards of the hospitals and appeared to be endemic in the ICU, emergency, pediatric and infection area throughout the years. Conclusion: Early and timely detection of ESBL-producing A. baumannii clones is useful for preventing their spread within the hospital. PFGE analysis is helpful for detection of common strains in different wards and prevention of further spread of these pulsotypes to other hospital environment.

  13. Identifying more epidemic clones during a hospital outbreak of multidrug-resistant Acinetobacter baumannii.

    Matthieu Domenech de Cellès

    Full Text Available Infections caused by multidrug-resistant bacteria are a major concern in hospitals. Current infection-control practices legitimately focus on hygiene and appropriate use of antibiotics. However, little is known about the intrinsic abilities of some bacterial strains to cause outbreaks. They can be measured at a population level by the pathogen's transmission rate, i.e. the rate at which the pathogen is transmitted from colonized hosts to susceptible hosts, or its reproduction number, counting the number of secondary cases per infected/colonized host. We collected data covering a 20-month surveillance period for carriage of multidrug-resistant Acinetobacter baumannii (MDRAB in a surgery ward. All isolates were subjected to molecular fingerprinting, and a cluster analysis of profiles was performed to identify clonal groups. We then applied stochastic transmission models to infer transmission rates of MDRAB and each MDRAB clone. Molecular fingerprinting indicated that 3 clonal complexes spread in the ward. A first model, not accounting for different clones, quantified the level of in-ward cross-transmission, with an estimated transmission rate of 0.03/day (95% credible interval [0.012-0.049] and a single-admission reproduction number of 0.61 [0.30-1.02]. The second model, accounting for different clones, suggested an enhanced transmissibility of clone 3 (transmission rate 0.047/day [0.018-0.091], with a single-admission reproduction number of 0.81 [0.30-1.56]. Clones 1 and 2 had comparable transmission rates (respectively, 0.016 [0.001-0.045], 0.014 [0.001-0.045]. The method used is broadly applicable to other nosocomial pathogens, as long as surveillance data and genotyping information are available. Building on these results, more epidemic clones could be identified, and could lead to follow-up studies dissecting the functional basis for variation in transmissibility of MDRAB lineages.

  14. Relationship between Antibiotic Resistance, Biofilm Formation, and Biofilm-Specific Resistance in Acinetobacter baumannii.

    Qi, Lihua; Li, Hao; Zhang, Chuanfu; Liang, Beibei; Li, Jie; Wang, Ligui; Du, Xinying; Liu, Xuelin; Qiu, Shaofu; Song, Hongbin

    2016-01-01

    In this study, we aimed to examine the relationships between antibiotic resistance, biofilm formation, and biofilm-specific resistance in clinical isolates of Acinetobacter baumannii. The tested 272 isolates were collected from several hospitals in China during 2010-2013. Biofilm-forming capacities were evaluated using the crystal violet staining method. Antibiotic resistance/susceptibility profiles to 21 antibiotics were assessed using VITEK 2 system, broth microdilution method or the Kirby-Bauer disc diffusion method. The minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) to cefotaxime, imipenem, and ciprofloxacin were evaluated using micro dilution assays. Genetic relatedness of the isolates was also analyzed by pulsed-field gel electrophoresis (PFGE) and plasmid profile. Among all the 272 isolates, 31 were multidrug-resistant (MDR), and 166 were extensively drug-resistant (XDR). PFGE typing revealed 167 pattern types and 103 clusters with a similarity of 80%. MDR and XDR isolates built up the main prevalent genotypes. Most of the non-MDR isolates were distributed in a scattered pattern. Additionally, 249 isolates exhibited biofilm formation, among which 63 were stronger biofilm formers than type strain ATCC19606. Population that exhibited more robust biofilm formation likely contained larger proportion of non-MDR isolates. Isolates with higher level of resistance tended to form weaker biofilms. The MBECs for cefotaxime, imipenem, and ciprofloxacin showed a positive correlation with corresponding MICs, while the enhancement in resistance occurred independent of the quantity of biofilm biomass produced. Results from this study imply that biofilm acts as a mechanism for bacteria to get a better survival, especially in isolates with resistance level not high enough. Moreover, even though biofilms formed by isolates with high level of resistance are always weak, they could still provide similar level of protection for the

  15. Simple Method for Markerless Gene Deletion in Multidrug-Resistant Acinetobacter baumannii.

    Oh, Man Hwan; Lee, Je Chul; Kim, Jungmin; Choi, Chul Hee; Han, Kyudong

    2015-05-15

    The traditional markerless gene deletion technique based on overlap extension PCR has been used for generating gene deletions in multidrug-resistant Acinetobacter baumannii. However, the method is time-consuming because it requires restriction digestion of the PCR products in DNA cloning and the construction of new vectors containing a suitable antibiotic resistance cassette for the selection of A. baumannii merodiploids. Moreover, the availability of restriction sites and the selection of recombinant bacteria harboring the desired chimeric plasmid are limited, making the construction of a chimeric plasmid more difficult. We describe a rapid and easy cloning method for markerless gene deletion in A. baumannii, which has no limitation in the availability of restriction sites and allows for easy selection of the clones carrying the desired chimeric plasmid. Notably, it is not necessary to construct new vectors in our method. This method utilizes direct cloning of blunt-end DNA fragments, in which upstream and downstream regions of the target gene are fused with an antibiotic resistance cassette via overlap extension PCR and are inserted into a blunt-end suicide vector developed for blunt-end cloning. Importantly, the antibiotic resistance cassette is placed outside the downstream region in order to enable easy selection of the recombinants carrying the desired plasmid, to eliminate the antibiotic resistance cassette via homologous recombination, and to avoid the necessity of constructing new vectors. This strategy was successfully applied to functional analysis of the genes associated with iron acquisition by A. baumannii ATCC 19606 and to ompA gene deletion in other A. baumannii strains. Consequently, the proposed method is invaluable for markerless gene deletion in multidrug-resistant A. baumannii. PMID:25746991

  16. Acinetobacter baumannii in intensive care unit: A novel system to study clonal relationship among the isolates

    Leonardis Francesca

    2008-06-01

    Full Text Available Abstract Background The nosocomial infections surveillance system must be strongly effective especially in highly critic areas, such as Intensive Care Units (ICU. These areas are frequently an epidemiological epicentre for transmission of multi-resistant pathogens, like Acinetobacter baumannii. As an epidemic outbreak occurs it is very important to confirm or exclude the genetic relationship among the isolates in a short time. There are several molecular typing systems used with this aim. The Repetitive sequence-based PCR (REP-PCR has been recognized as an effective method and it was recently adapted to an automated format known as the DiversiLab system. Methods In the present study we have evaluated the combination of a newly introduced software package for the control of hospital infection (VIGI@ct with the DiversiLab system. In order to evaluate the reliability of the DiversiLab its results were also compared with those obtained using f-AFLP. Results The combination of VIGI@ct and DiversiLab enabled an earlier identification of an A. baumannii epidemic cluster, through the confirmation of the genetic relationship among the isolates. This cluster regards 56 multi-drug-resistant A. baumannii isolates from several specimens collected from 13 different patients admitted to the ICU in a ten month period. The A. baumannii isolates were clonally related being their similarity included between 97 and 100%. The results of the DiversiLab were confirmed by f-AFLP analysis. Conclusion The early identification of the outbreak has led to the prompt application of operative procedures and precautions to avoid the spread of pathogen. To date, 6 months after the last A. baumannii isolate, no other related case has been identified.

  17. Investigation of the molecular epidemiology of Acinetobacter baumannii isolated from patients and environmental contamination.

    Ying, Chunmei; Li, Yongli; Wang, Yaping; Zheng, Bing; Yang, Chengde

    2015-09-01

    The objective of this work was to investigate correlations between Acinetobacter baumannii isolates from neurosurgical intensive care unit patients and its environment. This is a prospective, observational study. The minimal inhibitory concentrations of antimicrobial agents against 27 clinical and 28 environmental isolates were determined by the agar dilution method. Molecular genotyping was performed by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR), pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The presence of carbapenemase and metallo-β-lactamase genes were analyzed by specific PCRs and DNA sequencing. From the clinical A. baumannii isolates, 25.9% were found resistant to minocycline, 51.9% to cefoperazone-sulbactam, 59.3% to imipenem and 70% resistant to other antimicrobial agents. Environmental isolates were more sensitive compared with clinical isolates (P<0.05). Twenty-seven clinical isolates comprised three ERIC-PCR genotypes, four major PFGE pulsotypes and five distinct MLST sequence types (STs) (ST208, ST368, ST191, ST195, ST540), all belonging to CC92 with only one locus (gpi) difference among them. Twenty-eight environmental isolates showed more diverse genetic types than clinical isolates and comprised six ERIC-PCR groups, nine PFGE groups and two main STs (ST208, ST229). Four clinical and 15 environmental isolates could not be identified by MLST and were assigned to non-clonal STs. We identified the presence of the blaOXA-23 carbapenemase encoding gene in most of the clinical (21/27) but fewer in the environmental isolates (3/28). The A. baumannii strains isolated from patients were genetically similar to the environmental strains, with CC92 members as the major fraction but with different antibiotic susceptibilities. PMID:25873322

  18. Predictors of mortality in patients with extensively drug-resistant Acinetobacter baumannii pneumonia receiving colistin therapy.

    Choi, Ik Sung; Lee, Yu Ji; Wi, Yu Mi; Kwan, Byung Soo; Jung, Kae Hwa; Hong, Woong Pyo; Kim, June Myong

    2016-08-01

    The ratio of the area under the free (unbound) concentration-time curve to minimum inhibitory concentration (fAUC/MIC) was proposed to be the pharmacokinetic/pharmacodynamic index most strongly linked to the antibacterial effect of colistin against Acinetobacter baumannii. A retrospective study of patients who received colistin to treat pneumonia caused by extensively drug-resistant (XDR) A. baumannii over a 4-year period was performed to assess the impact of the colistin MIC on mortality. A total of 227 patients were included in the analysis. The 7-day and 14-day mortality rates of patients with XDR A. baumannii pneumonia receiving colistin therapy were 15.0% and 23.8%, respectively. In the multivariate analysis, Acute Physiology and Chronic Health Evaluation (APACHE) II score, days from index culture to first dose of colistin, underlying tumour and septic shock at presentation were independent predictors of mortality in patients with XDR A. baumannii pneumonia receiving colistin therapy. In the univariate analysis, the colistin dose based on ideal body weight (IBW) correlated with patient outcome. Therefore, the use of IBW appeared to be more appropriate to calculate the colistin dosage. In addition, these results highlight the clinical significance of colistin MIC in patients with XDR A. baumannii pneumonia receiving colistin therapy. Although MICs were in the 'susceptible' range, patients infected with isolates with high colistin MICs showed a poorer clinical response rate than patients infected with isolates with low colistin MICs. Further clinical studies are needed to evaluate the roles of colistin MIC for predicting mortality in XDR A. baumannii pneumonia with a high colistin MIC. PMID:27423416

  19. Emergence of multidrug-resistant Acinetobacter baumannii producing OXA-23 Carbapenemase in Qatar

    J.-M. Rolain

    2016-05-01

    Full Text Available The objective of our study was to describe the molecular support of carbapenem resistance from randomly selected clinical isolates of multidrug-resistant (MDR Acinetobacter baumannii as a pilot study from the Hamad Medical Corporation (HMC, Qatar. Results of our report will be used to study carbapenemases using molecular techniques in all isolated MDR A. baumannii. Forty-eight MDR A. baumannii were randomly selected from isolates preserved at HMC. Identification of all isolates was confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antibiotic resistance was tested phenotypically by Phoenix and confirmed by Etest. The molecular support of carbapenemases (blaOXA-23, blaOXA-24, blaOXA-58, blaNDM was investigated by real-time PCR. The epidemiologic relatedness of the isolates was verified by phylogenetic analysis based on partial sequences of CsuE and blaOXA-51 genes. All 48 isolates were identified as A. baumannii and were confirmed to be resistant to most antibiotics, especially meropenem, imipenems, ciprofloxacin, levofloxacin, amikacin, gentamicin and most of the β-lactams; they were sensitive to colistin. All the isolates were positive for blaOXA-23 and negative for the other tested carbapenemase genes. Clonality analysis demonstrated that different lineages were actually circulating in Qatar; and we suggest that an outbreak occurred in the medical intensive care unit of HMC between 2011 and 2012. Here we report the emergence of MDR A. baumannii producing the carbapenemase OXA-23 in Qatar.

  20. Strategies for the treatment of polymyxin B-resistant Acinetobacter baumannii infections.

    Menegucci, Thatiany Cevallos; Albiero, James; Migliorini, Letícia Busato; Alves, Janio Leal Borges; Viana, Giselle Fukita; Mazucheli, Josmar; Carrara-Marroni, Floristher Elaine; Cardoso, Celso Luiz; Tognim, Maria Cristina Bronharo

    2016-05-01

    In this study, the activity of meropenem (MEM), fosfomycin (FOF) and polymyxin B (PMB), alone and in combination, was analysed. In addition, optimisation of the pharmacodynamic index of MEM and FOF against six isolates of OXA-23-producing Acinetobacter baumannii (including three resistant to PMB) that were not clonally related was assessed. Antimicrobial combinations were evaluated by chequerboard analysis and were considered synergistic when the fractional inhibitory concentration index (FICI) was ≤0.5. Pharmacodynamic analyses of the MEM and FOF dosing schemes were performed by Monte Carlo simulation. The target pharmacodynamic index (%ƒT>MIC) for MEM and FOF was ≥40% and ≥70%, respectively, and a probability of target attainment (PTA) ≥0.9 was considered adequate. Among the PMB-resistant isolates, combinations of PMB+MEM and PMB+FOF+MEM showed the highest synergistic activity (FICI ≤0.125); isolates that were previously PMB-resistant were included in the susceptible category using CLSI interpretive criteria. Pharmacodynamic evaluation found that for a FOF minimum inhibitory concentration (MIC) of ≤16μg/mL, treatment both by bolus dosing and prolonged infusion achieved adequate PTA, whilst for MIC=32μg/mL only infusion achieved adequate PTA. For a MEM MIC of 4μg/mL, only the bolus treatment scheme with 1.5g q6h and the infusion schemes with 1.0g q8h, 1.5g q6h and 2.0g q8h achieved PTA ≥0.9. Results of antimicrobial and pharmacodynamic analyses can assist in treating infections caused by multidrug-resistant A. baumannii. However, in vivo clinical studies are essential to evaluate the true role of these compounds, including intravenous antimicrobial FOF therapy. PMID:27068675

  1. Epidemiologic and clinical impact of Acinetobacter baumannii colonization and infection: a reappraisal.

    Villar, Macarena; Cano, María E; Gato, Eva; Garnacho-Montero, José; Miguel Cisneros, José; Ruíz de Alegría, Carlos; Fernández-Cuenca, Felipe; Martínez-Martínez, Luis; Vila, Jordi; Pascual, Alvaro; Tomás, María; Bou, Germán; Rodríguez-Baño, Jesús

    2014-07-01

    Acinetobacter baumannii is one of the most important antibiotic-resistant nosocomial bacteria. We investigated changes in the clinical and molecular epidemiology of A. baumannii over a 10-year period. We compared the data from 2 prospective multicenter cohort studies in Spain, one performed in 2000 (183 patients) and one in 2010 (246 patients), which included consecutive patients infected or colonized by A. baumannii. Molecular typing was performed by repetitive extragenic palindromic polymerase chain reaction (REP-PCR), pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). The incidence density of A. baumannii colonization or infection increased significantly from 0.14 in 2000 to 0.52 in 2010 in medical services (p < 0.001). The number of non-nosocomial health care-associated cases increased from 1.2% to 14.2%, respectively (p < 0.001). Previous exposure to carbapenems increased in 2010 (16.9% in 2000 vs 27.3% in 2010, p = 0.03). The drugs most frequently used for definitive treatment of patients with infections were carbapenems in 2000 (45%) and colistin in 2010 (50.3%). There was molecular-typing evidence of an increase in the frequency of A. baumannii acquisition in non-intensive care unit wards in 2010 (7.6% in 2000 vs 19.2% in 2010, p = 0.01). By MSLT, the ST2 clonal group predominated and increased in 2010. This epidemic clonal group was more frequently resistant to imipenem and was associated with an increased risk of sepsis, although not with severe sepsis or mortality. Some significant changes were noted in the epidemiology of A. baumannii, which is increasingly affecting patients admitted to conventional wards and is also the cause of non-nosocomial health care-associated infections. Epidemic clones seem to combine antimicrobial resistance and the ability to spread, while maintaining their clinical virulence. PMID:25181313

  2. Resistance Markers and Genetic Diversity in Acinetobacter baumannii Strains Recovered from Nosocomial Bloodstream Infections

    Hanoch S. I. Martins

    2014-01-01

    Full Text Available In this study, phenotypic and genotypic methods were used to detect metallo-β-lactamases, cephalosporinases and oxacillinases and to assess genetic diversity among 64 multiresistant Acinetobacter baumannii strains recovered from blood cultures in five different hospitals in Brazil from December 2008 to June 2009. High rates of resistance to imipenem (93.75% and polymyxin B (39.06% were observed using the disk diffusion (DD method and by determining the minimum inhibitory concentration (MIC. Using the disk approximation method, thirty-nine strains (60.9% were phenotypically positive for class D enzymes, and 51 strains (79.6% were positive for cephalosporinase (AmpC. Using the E-test, 60 strains (93.75% were positive for metallo-β-lactamases (MβLs. All strains were positive for at least one of the 10 studied genes; 59 (92.1% contained blaVIM-1, 79.6% contained blaAmpC, 93.7% contained blaOXA23 and 84.3% contained blaOXA51. Enterobacteria Repetitive Intergenic Consensus (ERIC-PCR analysis revealed a predominance of certain clones that differed from each other. However, the same band pattern was observed in samples from the different hospitals studied, demonstrating correlation between the genotypic and phenotypic results. Thus, ERIC-PCR is an appropriate method for rapidly clustering genetically related isolates. These results suggest that defined clonal clusters are circulating within the studied hospitals. These results also show that the prevalence of MDR A. baumannii may vary among clones disseminated in specific hospitals, and they emphasize the importance of adhering to appropriate infection control measures.

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

    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.

  4. Carbapenem resistance and phenotypic detection of carbapenemases in clinical isolates of acinetobacter baumannii

    Gomty Mahajan

    2011-01-01

    Full Text Available Background and Objectives: Multidrug-resistant Acinetobacter baumannii (MDR-Ab reported worldwide has become one of the most difficult nosocomially acquired Gram-negative pathogens to control and treat. The clinical utility of carbapenems is under threat with the emergence of acquired carbapenemases, particularly Ambler class B metallo-lactamases (MBL. Because of the global increase in the occurrence and dissemination of MBLs, early detection is critical. This study was undertaken to detect resistance to carbapenems in clinical isolates of A. baumannii from hospitalized patients by both disk-diffusion and minimum inhibitory concentration (MIC methods and to assess the rate of carbapenemase and MBL production among the isolates. Materials and Methods : A. baumannii were identified from various clinical samples and antibiotic susceptibility profile was determined by the standard disk-diffusion method. Meropenem-resistant strains were tested further by agar dilution MIC for meropenem. Resistant isolates were screened for carbapenemase production by the modified Hodge test and positive isolates were further checked for metallo-β-lacatmase production by the EDTA disk synergy test. Results : 42 isolates (31.81% showed resistance to meropenem by the disk diffusion method. 47.6% were carbapenemase positive by the modified Hodge test and 19% were MBL producers phenotypically by the EDTA disc synergy test (EDS. These meropenem-resistant isolates were resistant to most of the other antibiotics tested. These 42 isolates were recovered mostly from patients admitted to intensive care units. Four isolates of the A. baumannii complex were pan drug resistant and showed resistance to even tigecycline and polymyxin B. Conclusion : Carbapenem resistance has been increasingly reported, necessitating their detection. This study reports simple, carbapenemase, and MBL detection method that can be easily incorporated into the daily routine of a clinical laboratory.

  5. Structures of the Class D Carbapenemase OXA-24 from Acinetobacter baumannii in Complex with Doripenem

    Schneider, Kyle D.; Ortega, Caleb J.; Renck, Nicholas A.; Bonomo, Robert A.; Powers, Rachel A.; Leonard, David A. (Case Western); (Grand Valley)

    2012-02-08

    The emergence of class D {beta}-lactamases with carbapenemase activity presents an enormous challenge to health practitioners, particularly with regard to the treatment of infections caused by Gram-negative pathogens such as Acinetobacter baumannii. Unfortunately, class D {beta}-lactamases with carbapenemase activity are resistant to {beta}-lactamase inhibitors. To better understand the details of the how these enzymes bind and hydrolyze carbapenems, we have determined the structures of two deacylation-deficient variants (K84D and V130D) of the class D carbapenemase OXA-24 with doripenem bound as a covalent acyl-enzyme intermediate. Doripenem adopts essentially the same configuration in both OXA-24 variant structures, but varies significantly when compared to the non-carbapenemase class D member OXA-1/doripenem complex. The alcohol of the 6a hydroxyethyl moiety is directed away from the general base carboxy-K84, with implications for activation of the deacylating water. The tunnel formed by the Y112/M223 bridge in the apo form of OXA-24 is largely unchanged by the binding of doripenem. The presence of this bridge, however, causes the distal pyrrolidine/sulfonamide group to bind in a drastically different conformation compared to doripenem bound to OXA-1. The resulting difference in the position of the side-chain bridge sulfur of doripenem is consistent with the hypothesis that the tautomeric state of the pyrroline ring contributes to the different carbapenem hydrolysis rates of OXA-1 and OXA-24. These findings represent a snapshot of a key step in the catalytic mechanism of an important class D enzyme, and might be useful for the design of novel inhibitors.

  6. Outbreak of resistant Acinetobacter baumannii: measures and proposal for prevention and control

    Roberta Maia de Castro Romanelli

    2009-10-01

    Full Text Available Acinetobacter baumannii colonization and infection, frequent in Intensive Care Unit (ICU patients, is commonly associated with high morbimortality. Several outbreaks due to multidrug-resistant (MDR A. baumanii have been reported but few of them in Brazil. This study aimed to identify risk factors associated with colonization and infection by MDR and carbapenem-resistant A. baumannii strains isolated from patients admitted to the adult ICU at HC/UFMG. A case-control study was performed from January 2007 to June 2008. Cases were defined as patients colonized or infected by MDR/carbapenem-resistant A. baumannii, and controls were patients without MDR/carbapenem-resistant A. baumannii isolation, in a 1:2 proportion. For statistical analysis, due to changes in infection control guidelines, infection criteria and the notification process, this study was divided into two periods. During the first period analyzed, from January to December 2007, colonization or infection by MDR/carbapenem-resistant A. baumannii was associated with prior infection, invasive device utilization, prior carbapenem use and clinical severity. In the multivariate analysis, prior infection and mechanical ventilation proved to be statistically significant risk factors. Carbapenem use showed a tendency towards a statistical association. During the second study period, from January to June 2008, variables with a significant association with MDR/carbapenem-resistant A. baumannii colonization/infection were catheter utilization, carbapenem and third-generation cephalosporin use, hepatic transplantation, and clinical severity. In the multivariate analysis, only CVC use showed a statistical difference. Carbapenem and third-generation cephalosporin use displayed a tendency to be risk factors. Risk factors must be focused on infection control and prevention measures considering A. baumanni dissemination.

  7. CRISPR-cas subtype I-Fb in Acinetobacter baumannii: evolution and utilization for strain subtyping.

    Karah, Nabil; Samuelsen, Ørjan; Zarrilli, Raffaele; Sahl, Jason W; Wai, Sun Nyunt; Uhlin, Bernt Eric

    2015-01-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are polymorphic elements found in the genome of some or all strains of particular bacterial species, providing them with a system of acquired immunity against invading bacteriophages and plasmids. Two CRISPR-Cas systems have been identified in Acinetobacter baumannii, an opportunistic pathogen with a remarkable capacity for clonal dissemination. In this study, we investigated the mode of evolution and diversity of spacers of the CRISPR-cas subtype I-Fb locus in a global collection of 76 isolates of A. baumannii obtained from 14 countries and 4 continents. The locus has basically evolved from a common ancestor following two main lineages and several pathways of vertical descent. However, this vertical passage has been interrupted by occasional events of horizontal transfer of the whole locus between distinct isolates. The isolates were assigned into 40 CRISPR-based sequence types (CST). CST1 and CST23-24 comprised 18 and 9 isolates, representing two main sub-clones of international clones CC1 and CC25, respectively. Epidemiological data showed that some of the CST1 isolates were acquired or imported from Iraq, where it has probably been endemic for more than one decade and occasionally been able to spread to USA, Canada, and Europe. CST23-24 has shown a remarkable ability to cause national outbreaks of infections in Sweden, Argentina, UAE, and USA. The three isolates of CST19 were independently imported from Thailand to Sweden and Norway, raising a concern about the prevalence of CST19 in Thailand. Our study highlights the dynamic nature of the CRISPR-cas subtype I-Fb locus in A. baumannii, and demonstrates the possibility of using a CRISPR-based approach for subtyping a significant part of the global population of A. baumannii. PMID:25706932

  8. CRISPR-cas subtype I-Fb in Acinetobacter baumannii: evolution and utilization for strain subtyping.

    Nabil Karah

    Full Text Available Clustered regularly interspaced short palindromic repeats (CRISPR are polymorphic elements found in the genome of some or all strains of particular bacterial species, providing them with a system of acquired immunity against invading bacteriophages and plasmids. Two CRISPR-Cas systems have been identified in Acinetobacter baumannii, an opportunistic pathogen with a remarkable capacity for clonal dissemination. In this study, we investigated the mode of evolution and diversity of spacers of the CRISPR-cas subtype I-Fb locus in a global collection of 76 isolates of A. baumannii obtained from 14 countries and 4 continents. The locus has basically evolved from a common ancestor following two main lineages and several pathways of vertical descent. However, this vertical passage has been interrupted by occasional events of horizontal transfer of the whole locus between distinct isolates. The isolates were assigned into 40 CRISPR-based sequence types (CST. CST1 and CST23-24 comprised 18 and 9 isolates, representing two main sub-clones of international clones CC1 and CC25, respectively. Epidemiological data showed that some of the CST1 isolates were acquired or imported from Iraq, where it has probably been endemic for more than one decade and occasionally been able to spread to USA, Canada, and Europe. CST23-24 has shown a remarkable ability to cause national outbreaks of infections in Sweden, Argentina, UAE, and USA. The three isolates of CST19 were independently imported from Thailand to Sweden and Norway, raising a concern about the prevalence of CST19 in Thailand. Our study highlights the dynamic nature of the CRISPR-cas subtype I-Fb locus in A. baumannii, and demonstrates the possibility of using a CRISPR-based approach for subtyping a significant part of the global population of A. baumannii.

  9. Comparative proteomics of inner membrane fraction from carbapenem-resistant Acinetobacter baumannii with a reference strain.

    Vishvanath Tiwari

    Full Text Available Acinetobacter baumannii has been identified by the Infectious Diseases Society of America as one of the six pathogens that cause majority of hospital infections. Increased resistance of A.baumannii even to the latest generation of β-lactams like carbapenem is an immediate threat to mankind. As inner-membrane fraction plays a significant role in survival of A.baumannii, we investigated the inner-membrane fraction proteome of carbapenem-resistant strain of A.baumannii using Differential In-Gel Electrophoresis (DIGE followed by DeCyder, Progenesis and LC-MS/MS analysis. We identified 19 over-expressed and 4 down-regulated proteins (fold change>2, p<0.05 in resistant strain as compared to reference strain. Some of the upregulated proteins in resistant strain and their association with carbapenem resistance in A.baumannii are: i β-lactamases, AmpC and OXA-51: cleave and inactivate carbapenem ii metabolic enzymes, ATP synthase, malate dehydrogenase and 2-oxoglutarate dehydrogenase: help in increased energy production for the survival and iii elongation factor Tu and ribosomal proteins: help in the overall protein production. Further, entry of carbapenem perhaps is limited by controlled production of OmpW and low levels of surface antigen help to evade host defence mechanism in developing resistance in A.baumannii. Present results support a model for the importance of proteins of inner-membrane fraction and their synergistic effect in the mediation of resistance of A.baumannii to carbapenem.

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

    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. PMID:19438062

  11. Protective Effect of a Synbiotic against Multidrug-Resistant Acinetobacter baumannii in a Murine Infection Model.

    Asahara, Takashi; Takahashi, Akira; Yuki, Norikatsu; Kaji, Rumi; Takahashi, Takuya; Nomoto, Koji

    2016-05-01

    This study investigated the ability of the probiotic Bifidobacterium breve strain Yakult (BbY) to protect against infection, as well as the potentiation of BbY activity by the synbiotic combination of BbY and prebiotic galactooligosaccharides (GOS). The study employed a mouse model of lethal intestinal multidrug-resistant Acinetobacter baumannii (MDRAb) infection. The endogenous intestinal microbiota was disrupted by the administration of multiple antibiotics, causing the loss of endogenous Bifidobacterium Oral infection of these mice with MDRAb resulted in marked growth of this organism. Additional treatment of the infected mice with a sublethal dose of 5-fluorouracil (5-FU) induced systemic invasion by MDRAb and subsequent animal death. The continuous oral administration of BbY increased the survival rate and inhibited the intestinal growth and invasion by MDRAb in the infection model. Disruptions of the intestinal environment and barrier function in the infected mice were attenuated by BbY. Protection against the MDRAb infection was markedly potentiated by a synbiotic combination of BbY and GOS, although GOS by itself did not provide protection. Negative correlations were observed between intestinal MDRAb and BbY counts or acetic acid levels; positive correlations were observed between acetic acid levels and intestinal epithelium expression of tight-junction-related genes. These results demonstrated that the probiotic and synbiotic markedly potentiated protection against fatal intestinal infection caused by a multidrug-resistant bacterium. Probiotics and synbiotics are presumed to provide protection by compensation for the disrupted indigenous populations, thereby maintaining the intestinal environments and barrier functions otherwise targeted during opportunistic infection by MDRAb. PMID:26953197

  12. Immunization against multidrug-resistant Acinetobacter baumannii effectively protects mice in both pneumonia and sepsis models.

    Weiwei Huang

    Full Text Available OBJECTIVE: Acinetobacter baumannii is considered the prototypical example of a multi- or pan- drug-resistant bacterium. It has been increasingly implicated as a major cause of nosocomial and community-associated infections. This study proposed to evaluate the efficacy of immunological approaches to prevent and treat A. baumannii infections. METHODS: Mice were immunized with outer membrane vesicles (OMVs prepared from a clinically isolated multidrug-resistant strain of A. baumannii. Pneumonia and sepsis models were used to evaluate the efficacy of active and passive immunization with OMVs. The probable effective mechanisms and the protective potential of clonally distinct clinical isolates were investigated in vitro using an opsonophagocytic assay. RESULTS: Intramuscular immunization with OMVs rapidly produced high levels of OMV-specific IgG antibodies, and subsequent intranasal challenge with A. baumannii elicited mucosal IgA and IgG responses. Both active and passive immunization protected the mice from challenges with homologue bacteria in a sepsis model. Bacterial burden in bronchoalveolar lavage fluids (BALF, lung, and spleen, inflammatory cell infiltration in BALF and lung, and inflammatory cytokine accumulation in BALF was significantly suppressed in the pneumonia model by both active and passive immunization strategies. The antisera from immunized mice presented with significant opsonophagocytic activities in a dose-dependent manner against not only homologous strains but also five of the other six clonally distinct clinical isolates. CONCLUSIONS: Utilizing immunological characteristics of outer membrane proteins to elevate protective immunity and circumvent complex multidrug-resistance mechanisms might be a viable approach to effectively control A. baumannii infections.

  13. Interplay of posttranslational modifications in Sp1 mediates Sp1 stability during cell cycle progression.

    Wang, Yi-Ting; Yang, Wen-Bin; Chang, Wen-Chang; Hung, Jan-Jong

    2011-11-18

    Although Sp1 is known to undergo posttranslational modifications such as phosphorylation, glycosylation, acetylation, sumoylation, and ubiquitination, little is known about the possible interplay between the different forms of Sp1 that may affect its overall levels. It is also unknown whether changes in the levels of Sp1 influence any biological cell processes. Here, we identified RNF4 as the ubiquitin E3 ligase of Sp1. From in vitro and in vivo experiments, we found that sumoylated Sp1 can recruit RNF4 as a ubiquitin E3 ligase that subjects sumoylated Sp1 to proteasomal degradation. Sp1 mapping revealed two ubiquitination-related domains: a small ubiquitin-like modifier in the N-terminus of Sp1(Lys16) and the C-terminus of Sp1 that directly interacts with RNF4. Interestingly, when Sp1 was phosphorylated at Thr739 by c-Jun NH(2)-terminal kinase 1 during mitosis, this phosphorylated form of Sp1 abolished the Sp1-RNF4 interaction. Our results show that, while sumoylated Sp1 subjects to proteasomal degradation, the phosphorylation that occurs during the cell cycle can protect Sp1 from degradation by repressing the Sp1-RNF4 interaction. Thus, we propose that the interplay between posttranslational modifications of Sp1 plays an important role in cell cycle progression and keeps Sp1 at a critical level for mitosis. PMID:21983342

  14. COST-EFFECTIVE PRODUCTION OF THE BIO-PLASTIC POLY-β-HYDROXYBUTYRATE USING ACINETOBACTER BAUMANNII ISOLATE P39

    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.

  15. Prevalence of antibiotic-resistant Acinetobacter baumannii in a 1000-bed tertiary care hospital in Tehran, Iran

    Rahbar Mohammad

    2010-04-01

    Full Text Available Acinetobacter baumannii is a ubiquitous pathogen that has emerged as a major cause of healthcare-associated infections. Acinetobacter baumannii usually causes respiratory tract, urinary tract, blood stream and surgical site infections. They are of increasing importance because of its ability to rapidly develop resistance to the major groups of antibiotics. There are few data available on the antimicrobial susceptibility of A. baumannii in Iran. During the period of study from July 2005 to November 2006, a total of 88 strains of A. baumannii were isolated from clinical specimens obtained from patients hospitalized in an Iranian 1000-bed tertiary care hospital. Conventional bacteriological methods were used for identification of A. baumannii. Susceptibility testing was performed by the method recommended by Clinical Laboratory and Standards Institute (CLSI. The majority of isolates were from respiratory tract specimens. The organism showed high rate of resistance to ceftriaxone (90.9%, piperacillin (90.9%, ceftazidime (84.1%, amikacin (85.2% and ciprofloxacin (90.9%. Imipenem was the most effective antibiotic against A. baumannii and the rate of resistance for imipenem was 4.5%. The second most effective antibiotic was tobramycin, and 44.3% of A. baumannii isolates were resistant to this antibiotic. In conclusion, our study showed that the rate of resistance in A. baumannii to imipenem was low. There was a significant relationship between demographic features of patients such as age, undergoing mechanical ventilation, length of hospital stay and drug resistance.

  16. Whole-genome pyrosequencing of an epidemic multidrug-resistant Acinetobacter baumannii strain belonging to the European clone II group

    Iacono, M.; Villa, L.; Fortini, D.; Bordoni, R.; Imperi, F.; Bonnal, R.J.P.; Sicheritz-Pontén, Thomas; De Bellis, G.; Visca, P.; Cassone, A.; Carattoli, A.

    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...... of A. baumannii ATCC 17978 and Acinetobacter baylyi ADP1, with the aim of identifying novel genes related to virulence and drug resistance. A. baumannii ACICU has a single chromosome of 3,904,116 bp (which is predicted to contain 3,758 genes) and two plasmids, pACICUI and pACICU2, of 28,279 and 64...... than in ATCC 17978 and ADP1 (76.2, 57.2, and 62.5 transporters per Mb of genome, respectively). An antibiotic resistance island, AbaR2, was identified in ACICU and had plausibly evolved by reductive evolution from the AbaR1 island previously described in multiresistant strain A. baumannii AYE. Moreover...

  17. Pantoea vagans sp. nov., Pantoea eucalypti sp. nov., Pantoea deleyi sp. nov. and Pantoea anthophila sp. nov.

    Brady, Carrie L; Venter, Stephanus N; Cleenwerck, Ilse; Engelbeen, Katrien; Vancanneyt, Marc; Swings, Jean; Coutinho, Teresa A

    2009-09-01

    Bacteria isolated from eucalyptus leaves and shoots showing symptoms of blight and die-back collected in Uganda, Uruguay and Argentina and from maize displaying brown stalk rot symptoms in South Africa were tentatively placed in the genus Pantoea on the basis of phenotypic and biochemical tests. These isolates, together with two strains (LMG 2558 and LMG 2560) previously assigned to Pantoea agglomerans based on protein electrophoregrams but later excluded from this species, were further investigated using molecular techniques. 16S rRNA gene sequencing and multilocus sequence analyses (MLSA) revealed that the strains were phylogenetically closely related to Pantoea agglomerans, Pantoea stewartii and Pantoea ananatis. MLSA and amplified fragment length polymorphism analysis placed the strains into four separate clusters, not containing any of the type strains of species of the genus Pantoea. DNA-DNA hybridization confirmed the classification of the isolates into four novel species, for which the names Pantoea vagans sp. nov. (type strain R-21566T=LMG 24199T=BCC 105T=BD 765T), Pantoea eucalypti sp. nov. (type strain R-25678T=LMG 24197T=BCC 076T=BD 769T), Pantoea deleyi sp. nov. (type strain R-31523T=LMG 24200T=BCC 109T=BD 767T) and Pantoea anthophila sp. nov. (type strain LMG 2558T=BD 871T=NCPPB 1682T) are proposed. PMID:19620357

  18. Drug Resistance of Acinetobacter Baumannii%鲍曼不动杆菌的耐药情况

    唐希才; 郭亚云; 郭旭光; 夏勇; 江镜全

    2011-01-01

    [Objective] To understand the clinical distribution and the resistance of acinetobacter baumanii to in order to antibiotics, and provide evidence for the clinical therapeutics. [Methods]The strains identification and drug resistance of Acinetobacter baumanii were detected by Walkaway automatic bacterium identifying and drug sensitivity analyzing systems, and the results were analyzed [Results] There were 85 specimens detected with Acinetobacter baumanii , including sputum, blood, urine, cerebrospinal fluid (CSF) and incisional secretion, etc. The main specimen was the sputum (72.94% ). The drug resistant rates to Cefoperazone / sul-bactam and imipenem was 11.76% and 30.59% respectively, and to other antibiotics were high. [ Conclusion ] Acinetobacter baumanii mainly causes lower respiratory tract infection, had a high drug resistance rate to most antibiotics, imipenem and sulbactam are the first choice to treat the infections caused by Acinetobacter baumanii. It is very important to select rational drugs according to the results of antibiotics susceptibility tests to control the infection effectively and delay the occurrence of bacteria resistance.%目的 了解鲍曼不动杆菌的临床分布及其对常用抗生素的耐药状况,为临床使用抗生素治疗提供依据。方法 用Walkaway自动化细菌鉴定及药敏分析系统对菌落进行鉴定并做药敏试验,对检出的鲍曼不动杆菌的药敏结果做一分析。结果 在检出鲍曼不动杆菌的标本中有痰液、血液、尿液、脑脊液、伤口分泌物等标本,共85份。其中主要为痰液,占所有标本的72.94%。在药敏结果中,鲍曼不动杆菌对头孢哌酮/舒巴坦(舒普深)耐药率为¨.76%、亚胺培南30.59%,对其他抗生素耐药性较高。结论 鲍曼不动杆菌主要引起下呼吸道感染,其敏感抗生素谱窄,舒普深、亚胺培南可作为治疗的首选药物,对常用抗生素的使用,临床应根据药物敏感

  19. Draft Genome Sequence of a Multidrug-Resistant Klebsiella pneumoniae Carbapenemase-Producing Acinetobacter baumannii Sequence Type 2 Isolate from Puerto Rico.

    Martínez, Teresa; Ropelewski, Alexander J; González-Mendez, Ricardo; Vázquez, Guillermo J; Robledo, Iraida E

    2016-01-01

    We report here the draft genome sequence of Acinetobacter baumannii strain M3AC14-8, sequence type 2 (ST2), carrying a chromosomally carried blaKPC-2 gene. The draft genome consists of a total length of 4.11 Mbp and a G+C content of 39.25%. PMID:27540056

  20. Presence of high-risk clones of OXA-23-producing Acinetobacter baumannii (ST79) and SPM-1-producing Pseudomonas aeruginosa (ST277) in environmental water samples in Brazil.

    Turano, Helena; Gomes, Fernando; Medeiros, Micheli; Oliveira, Silvane; Fontes, Lívia C; Sato, Maria I Z; Lincopan, Nilton

    2016-09-01

    This study reports the presence of hospital-associated high-risk lineages of OXA-23-producing ST79 Acinetobacter baumannii and SPM-1-producing ST277 Pseudomonas aeruginosa in urban rivers in Brazil. These findings indicate that urban rivers can act as reservoirs of clinically important multidrug-resistant bacteria, which constitute a potential risk to human and animal health. PMID:27342783

  1. Draft Genome Sequence of Alkane-Degrading Acinetobacter venetianus JKSF02, Isolated from Contaminated Sediment of the San Jacinto River in Houston, Texas

    Damania, Ashish

    2016-01-01

    Acinetobacter venetianus JKSF02 was isolated from contaminated sediment in eastern Houston, Texas along the San Jacinto River. This microorganism specializes in n-alkane degradation and is well suited for bioremediation of the petroleum hydrocarbon deposited throughout the region by shipping and industrial activity from the Houston Ship Channel. PMID:27081144

  2. Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24

    Yun, Sung Ho; Choi, Chi-Won; Yi, Yoon-Sun; Kim, Jonghyun; Chung, Young-Ho; Park, Edmond Changkyun; Kim, Seung Il

    2016-01-01

    Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs), including benzene, toluene, and xylene (BTX), as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX. PMID:27124467

  3. Surveillance of multidrug resistance-associated genes in Acinetobacter baumannii isolates from elderly patients

    Zhe DONG

    2012-03-01

    Full Text Available Objective To understand the status of multidrug resistance-associated genes carried by Acinetobacter baumannii isolates from elderly patients in our hospital in order to provide a basis for surveillance of drug-resistance and inflection control. Methods One hundred and twenty A. baumannii isolates were collected from elderly patients between 2008 and 2010. The mean age of the patients was 85 (65 to 95 years. Whonet 5.6 software was used to analyze the resistance rate of 16 antimicrobial agents. Polymerase chain reaction (PCR and the sequencing method were adopted to detect 10 kinds of resistance genes (blaOXA-51-like, blaOXA- 23-like, blaOXA-24-like, blaOXA-58-like, blaTEM, blaampC, armA, ISAba1, intI 1, and intI 2. The corresponding resistance gene profiling(RGP was analyzed and designated according to the status of resistance genes. Results The resistance rates to the remaining 15 kinds of antibiotics varied between 70.8% and 97.5%, with the exception of the sensitivity rate to polymyxin B by up to more than 90%. The positivity rates of blaOXA-51-like, blaOXA-23-like, blaOXA-58-like, blaTEM, blaampC, armA, ISAba1 and intI 1 were 100%, 81.7%, 0.8%, 10.8%, 91.7%, 81.7%, 86.7%, and 83.3% respectively. A total of 18 kinds of drug-resistant gene maps were found, but blaOXA-24-like and intI 2 were not detected. Among these gene maps, the rate of RGP1 (blaOXA-23-like+blaampC+armA+ISAba1+ intI 1 was as high as 60.8%. Conclusions A. baumannii isolates from elderly patients have a higher carrying rate of drug-resistant genes, resulting in severe multidrugresistant conditions. Therefore, full-time infection control personnel and clinical physicians should actively participate in the surveillance, prevention, and control of infections caused by A. baumannii in the elderly.

  4. INHIBITION OF Acinetobacter baumannii ADHESION BY ANTI-FIMBRIAL ANTIBODY: THE FIMBRIAL ANTIGEN EFFECTIVENESS

    Hadeel K. Musafer

    2013-01-01

    Full Text Available Collecting samples of Acinetobacter baumannii taken from different clinical cases of wounds, septicemia, and urinary tract infections. That was accomplished by taking (296 samples from Baghdad educational hospital and Ibn-al-Baladi hospital. Samples were cultured on solid media (McConkey and blood agars, and according to microscopical, cultural, and biochemical identification, in addition to using API 20-E system, (21 isolates of A. baumannii were identified and in percentage of 47.619, 9.523, 14.285, and 28.571 for wound, blood, sputum, and urine samples, respectively. Methods: detection of fimbriated bacterial isolates among 21 isolates, and all those isolated were fimbriae forming isolates; isolate number (9 was selected as an effective isolate in formation of fimbriae. Non-forming fimbriae isolate of Shigella flexneri is used as negative control. Results and Conclusion: the average of adherence of fimbriated bacterial cell with human epithelial cells was reached (50 adherent bacterial cell per epithelial cell compared with the average of adherence of control isolate (12 adherent bacterial cell per epithelial cell, the inhibition processes are performed: Inhibition of bacterial adherence by specific antibodies of fimbriae antigen showed inhibition effect of adherence in respect to fimbriated isolate A. baumannii 9 also the subminimum inhibitory concentration for four antibiotics (Gentamicin, Tobramycin, Cefepime, and Amikacin inhibit the adherence of fimbriated isolate. The isolates (used in the study have the ability to agglutinate Saccharomyces cerevisiae and human red blood corpuscles (RBCs. The study of effect of different fimbriae extract concentrations (25, 50, 100 μg/ml on immune cells; consequently, reached to the following results: Concentrations of (25, 50, 100 μg/ml showed a negative effect on lymphocyte and PMNs viability which increased significantly (P≤0.05 with increasing of fimbriae extract concentration. On the other hand

  5. Predictors of Multidrug Resistant Acinetobacter Baumannii Infections in Surgical Intensive Care Patients: A Retrospective Analysis

    Aynur Camkıran

    2011-08-01

    Full Text Available Objective: Multidrug resistant Acinetobacter baumannii (MRAB is an important cause of hospital acquired infection and leads to an increasing morbidity and mortality in intensive care units (ICU. The aim of this study was to investigate the predictors of MRAB infection in surgical ICU patients. Material and Method: The charts of the patients who were admitted to the ICU between January 2008 and August 2010 were reviewed to identify patients with MRAB infection. Recorded data were as follows: age, sex, medical history, underlying surgical pathology, Acute Physiology and Chronic Health Evaluation II score (APACHE II and Glasgow Coma Score on ICU admission,presence of invasive procedures (intubation, arterial, central venous lines, urinary catheters, and renal replacement therapy, days in ICU and white blood cells (WBC and lactate count on infection day, infection site, complications (such as organ/system failure, length of stay (LOS in the ICU and hospital, and final outcome. Results: During the study period 25 patients with MRAB infection were identified. When compared with their matched control group (n=25, patients with MRAB infection had a significantly higher mean APACHE II score (p=0.001 and more frequently had an open wound (p=0.002 or required mechanical ventilation (p=0.005, with respiratory system disease (p=0.03, arterial catheterization (p=0.006, and central venous catheterization (p=0.004. Multivariate logistic regression revealed that APACHE II score (OR,1.155; CI, 1.008-1.324; p= 0.038 and open wound (OR, 27.77; CI, 2.020-333.333; p=0.018 were predictors of MRAB infection in these patients. Compared to their controls, patients with MRAB infection hand a longer LOS in ICU (36.44±30.44 days vs 7.80±8.13 days, p<0.000 and hospital (55.12±40.81 days vs 19.04±13.44 days, p<0.000. In hospital mortality rates for patients with MRAB infection and their controls were 56% and 32%, respectively (p=0.154. Conclusion: Our results indicate

  6. Multiple drug resistant carbapenemases producing Acinetobacter baumannii isolates harbours multiple R-plasmids

    Rajagopalan Saranathan

    2014-01-01

    Full Text Available Background & objectives: The nosocomial human pathogen Acinetobacter baumannii has high propensity to develop resistance to antimicrobials and to become multidrug resistant (MDR, consequently complicating the treatment. This study was carried out to investigate the presence of resistant plasmids (R-plasmids among the clinical isolates of A. baumannii. In addition, the study was performed to check the presence of common β-lactamases encoding genes on these plasmids. Methods: A total of 55 clinical isolates of A. baumannii were included in the study and all were subjected to plasmid DNA isolation, followed by PCR to check the presence of resistance gene determinants such as blaOXA-23 , blaOXA-51, blaOXA-58 and blaIMP-1 on these plasmids that encode for oxacillinase (OXA and metallo-β-lactamase (MBL type of carbapenemases. Plasmid curing experiments were carried out on selected isolates using ethidium bromide and acridine orange as curing agents and the antibiotic resistance profiles were evaluated before and after curing. Results: All the isolates were identified as A. baumannii by 16SrDNA amplification and sequencing. Plasmid DNA isolated from these isolates showed the occurrence of multiple plasmids with size ranging from 500bp to ≥ 25 kb. The percentage of blaOXA-51 and blaOXA-23 on plasmids were found to be 78 and 42 per cent, respectively and 20 isolates (36% carried blaIMP-1 gene on plasmids. Significant difference was observed in the antibiograms of plasmid cured isolates when compared to their parental ones. The clinical isolates became susceptible to more than two antibiotic classes after curing of plasmids indicating plasmid borne resistance. Interpretation & conclusions: Our study determined the plasmid mediated resistance mechanisms and occurrence of different resistance genes on various plasmids isolated from MDR A. baumannii. The present findings showed the evidence for antibiotic resistance mediated through multiple plasmids in

  7. The influence of carbapenem resistance on mortality in solid organ transplant recipients with Acinetobacter baumannii infection

    de Gouvêa Erika

    2012-12-01

    Full Text Available Abstract Background Infection with carbapenem-resistant Acinetobacter baumannii has been associated with high morbidity and mortality in solid organ transplant recipients. The main objective of this study was to assess the influence of carbapenem resistance and other potential risk factors on the outcome of A. baumannii infection after kidney and liver transplantation. Methods Retrospective study of a case series of A. baumannii infection among liver and renal transplant recipients. The primary outcome was death associated with A. baumannii infection. Multivariate logistic regression was used to assess the influence of carbapenem resistance and other covariates on the outcome. Results Forty-nine cases of A. baumannii infection affecting 24 kidney and 25 liver transplant recipients were studied. Eighteen cases (37% were caused by carbapenem-resistant isolates. There were 17 (35% deaths associated with A. baumannii infection. In unadjusted analysis, liver transplantation (p = 0.003, acquisition in intensive care unit (p = 0.001, extra-urinary site of infection (p A. baumannii infection. The number of deaths associated with A. baumannii infection was higher among patients infected with carbapenem-resistant isolates, but the difference was not significant (p = 0.28. In multivariate analysis, the risk of A. baumannii-associated mortality was higher in patients with infection acquired in the intensive care unit (odds ratio [OR] = 34.8, p = 0.01 and on mechanical ventilation (OR = 15.2, p = 0.04. Appropriate empiric antimicrobial therapy was associated with significantly lower mortality (OR = 0.04, p = 0.03, but carbapenem resistance had no impact on it (OR = 0.73, p = 0.70. Conclusion These findings suggest that A. baumannii-associated mortality among liver and kidney transplant recipients is influenced by baseline clinical severity and by the early start of appropriate therapy, but not by carbapenem

  8. Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection

    DAI Ning; ZHANG Wei; LI Jia-shu; YU Qin; WAN Huan-ying; MU Lan; ZHONG Xiao-ning; WEI Li-ping; MA Jian-jun; WANG Qiu-yue; HU Ke; LI De-zhi; TIAN Gui-zhen; CAI Shao-xi; WANG Rui-qin; HE Bei; WANG Si-qin; WANG Zhan-wei; ZHAO Su-rui; GAO Zhan-cheng; CHEN Ji-chao; CHEN Yu-sheng; GENG Rong; HU Ying-hui; YANG Jing-ping; DU Juan; HU Cheng-ping

    2010-01-01

    Background Acinetobacter baumanii (A. baumanii) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A.baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs).Methods Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system.Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods.Results Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains.Aminoglycoside-modifying enzyme gene aac-3-la was found in 23 strains, and the aac-6'-lb gene in 19 strains, aac-3-la and aac-6'-lb genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype.Conclusions A. baumaniican carry multiple drug

  9. Isolation and Characterization of a Virulent Bacteriophage AB1 of Acinetobacter baumannii

    Jia Shiru

    2010-04-01

    Full Text Available Abstract Background Acinetobacter baumannii is an emerging nosocomial pathogen worldwide with increasing prevalence of multi-drug and pan-drug resistance. A. baumannii exists widely in natural environment, especially in health care settings, and has been shown difficult to be eradicated. Bacteriophages are often considered alternative agent for controlling bacterial infection and contamination. In this study, we described the isolation and characterization of one virulent bacteriophage AB1 capable of specifically infecting A. baumannii. Results A virulent bacteriophage AB1, specific for infecting a clinical strain A. baumannii KD311, was first isolated from marine sediment sample. Restriction analysis indicated that phage AB1 was a dsDNA virus with an approximate genome size of 45.2 kb to 46.9 kb. Transmission electron microscopy showed that phage AB1 had an icosahedral head with a non-contractile tail and collar or whisker structures, and might be tentatively classified as a member of the Siphoviridae family. Proteomic pattern of phage AB1, generated by SDS-PAGE using purified phage particles, revealed five major bands and six minor bands with molecular weight ranging from 14 to 80 kilo-dalton. Also determined was the adsorption rate of phage AB1 to the host bacterium, which was significantly enhanced by addition of 10 mM CaCl2. In a single step growth test, phage AB1 was shown having a latent period of 18 minutes and a burst size of 409. Moreover, pH and thermal stability of phage AB1 were also investigated. At the optimal pH 6.0, 73.2% of phages survived after 60 min incubation at 50°C. When phage AB1 was used to infect four additional clinical isolates of A. baumannii, one clinical isolate of Stenotrophomonas maltophilia, and Pseudomonas aeruginosa lab strains PAK and PAO1, none of the tested strains was found susceptible, indicating a relatively narrow host range for phage AB1. Conclusion Phage AB1 was capable of eliciting efficient lysis

  10. 鲍曼不动杆菌临床分布和耐药性分析%Clinical Distribution and Drug Resistance of Acinetobacter baumanii

    王厚照; 张玲; 尚碧莲; 孙光伟; 邸玥莹

    2011-01-01

    目的 了解临床标本中鲍曼不动杆菌的临床分布和耐药情况,为临床控制感染提供依据.方法 采用回顾性方法统计分析93株鲍曼不动杆菌的标本来源、感染科室分布及耐药状况.结果 鲍曼不动杆菌最常出现在痰液标本中;神经外科ICU病房鲍曼不动杆菌的检出率较高;鲍曼不动杆菌耐药现象比较严重,对多种抗生素耐药率均大于30%(除头孢哌酮/舒巴坦和亚胺培南).结论 鲍曼不动杆菌为多重耐药菌株,临床要重视合理使用抗菌药物,加强预防标准,控制其引发的院内感染.%Objective To investigate the clinical distribution and drug resistance of Acinetobacter baumanii in clinical specimens, and to provide the reference for control of nosocomial infections.Methods Sample sources, clinical distribution and drug resistance of 93 strains of Acinetobacter baumanii were retrospectively analyzed.Results Among the 93 specimens, the dominant specimen was the sputum.The detection rate of Acinetobacter baumanii in the ICU of Department of Neurosurgery was the highest.The drug resistant rates to most antibacterials were over 30% except SCF and imipenem.Conclusions Acinetobacter baumani was multi - drug resistant organism.Rational application of antibiotics and standard prevention should be strengthened to control the nosocomial infection caused by Acinetobacter baumani mainly.

  11. An Sp1/Sp3 binding polymorphism confers methylation protection.

    Yanis A Boumber

    Full Text Available Hundreds of genes show aberrant DNA hypermethylation in cancer, yet little is known about the causes of this hypermethylation. We identified RIL as a frequent methylation target in cancer. In search for factors that influence RIL hypermethylation, we found a 12-bp polymorphic sequence around its transcription start site that creates a long allele. Pyrosequencing of homozygous tumors revealed a 2.1-fold higher methylation for the short alleles (P<0.001. Bisulfite sequencing of cancers heterozygous for RIL showed that the short alleles are 3.1-fold more methylated than the long (P<0.001. The comparison of expression levels between unmethylated long and short EBV-transformed cell lines showed no difference in expression in vivo. Electrophorectic mobility shift assay showed that the inserted region of the long allele binds Sp1 and Sp3 transcription factors, a binding that is absent in the short allele. Transient transfection of RIL allele-specific transgenes showed no effects of the additional Sp1 site on transcription early on. However, stable transfection of methylation-seeded constructs showed gradually decreasing transcription levels from the short allele with eventual spreading of de novo methylation. In contrast, the long allele showed stable levels of expression over time as measured by luciferase and approximately 2-3-fold lower levels of methylation by bisulfite sequencing (P<0.001, suggesting that the polymorphic Sp1 site protects against time-dependent silencing. Our finding demonstrates that, in some genes, hypermethylation in cancer is dictated by protein-DNA interactions at the promoters and provides a novel mechanism by which genetic polymorphisms can influence an epigenetic state.

  12. Acinetobacter spp. e Pseudomonas aeruginosa resistentes aos carbapenêmicos no Hospital Universitário de Santa Maria, Rio Grande do Sul =Carbapenem-resistant Acinetobacter spp. and Pseudomonas aeruginosa at the University Hospital of Santa Maria, Rio Grande do Sul state, Brazil

    Brezolin, Daiane; Santos, Silvana Oliveira dos; Rosmari HÖRNER

    2014-01-01

    Objetivos: Avaliar as características de sensibilidade a antimicrobianos de Acinetobacter spp. e Pseudomonas aeruginosa resistentes aos carbapenêmicos, isolados entre agosto de 2011 a janeiro de 2012 de pacientes internados no Hospital Universitário de Santa Maria, na cidade de Santa Maria, Rio Grande do Sul, Brasil. Métodos: Foi realizado um estudo retrospectivo através da consulta ao banco de dados do Laboratório de Microbiologia, onde foram incluídos todos os isolados de Acinetobacter s...

  13. [Antibiotic resistance of Acinetobacter baumannii strains isolated from clinical specimens in the "Marius Nasta" Pneumology Institute, Bucharest].

    Moisoiu, Adriana; Ionită, Monica; Sârbu, Lăcrămioara; Stoica, Corina; Grigoriu, Liliana

    2014-01-01

    Acinetobacter baumannii (A. baumannii) is one of the leading causes of morbidity and mortality in patients who are in critical condition in hospitals and especially in intensive care units (ICU). Long time considered a bacterium with low virulence, A. baumannii has more recently become a cause for major concern in clinical practice due to its high level of antimicrobial resistance. The extend of infections with Acinetobacter baumannii in ICU is caused by multiple factors, such as mechanical ventilation, invasive procedures, the use of a large number of broad spectrum antibiotics and transmission through the hands of medical staff In this study we evaluated the resistance to antibiotics of 213 non-duplicated strains of A. baumannii isolated in the bacteriology laboratory of the "Marius Nasta" lnstitute of Pneumophtisiology (IPMN) from January 2012 to December 2013. These strains originated from patients in medical wards (56), ICU (143) and surgery (14). Strains identification was performed by classical methods on multitest media and with API kits (Bio Merieux). The antibiotic sensitivity was performed on Mueller-Hinton media in accordance with CLSI2013. Analysis of the resistance to antibiotics was the following: carbenicilin (87.3%), ceftriaxone (87.3%), cefoperazone with sulbactam (84.9%), ceftazidime (79.3%), carbapenems (imipenem and/or meropenem--75.1%), fluoroquinolones (ciprofloxacin and/orlevofloxacin--73.7%), cefepime (66.6%), piperacilin with tazobactam (62.4%), amikacin (50.2%), netilmicin (45%), gentamicin (42.7%) and tobramycin (35.6%). In our study, we only found two strains of Acinetobacter baumannii with resistance to colistin and 70 (32.8%) strains sensitive only to colistin, but resistant to all other antibiotics tested. A. baumannii is a pathogen with rapid spread and extended resistance to even newer antimicrobial agents. Due to its ability to survive in the hospital environment, A. baumannii has the immense potential to cause nosocomial

  14. SP-100 Reactor Subsystem Development

    Demuth, Scott F.

    1994-07-01

    The SP-100 reactor subsystem consists of the pressure vessel, vessel internals, and fuel elements. Type A (standard) Nb-1Zr and rhenium materials development efforts related to fabrication of the vessel, vessel internals, and fuel cladding/liner have been completed. Type A and Type C (PWC-11) Nb-1Zr loop fabrication has been successfully demonstrated by prototypic testing with flowing lithium at 1350 K for 1500 hr. Development of UN fuel has been completed, and the performance validated by irradiation testing to the full life (7 yr. full power) burnup of 6 atom %. Neutronic and hydraulic core performance have been validated by engineering mockup critical experiments in the Zero Power Physics Reactor at Argonne National Laboratory, and detailed core hydraulic flow testing with water. Essentially all feasibility issues have been settled for the full life SP-100 reactor subsystem. Remaining SP-100 reactor subsystem development efforts are focused on further reducing mass by the use of Type C (PWC-11) Nb-1Zr rather than Type A, and demonstrating fuel life for beyond full life to perhaps 9 atom % burnup.

  15. Nickel biosorption by Acinetobacter baumannii and Pseudomonas aeruginosa isolated from industrial wastewater Bioadsorção de niquel por Acinetobacter baumannii e Pseudomonas aeruginosa isoladas de águas residuais industriais

    Carlos E. Rodríguez

    2006-12-01

    Full Text Available Nickel biosorption ability was evaluated in two bacterial strains: Acinetobacter baumannii UCR-2971 and Pseudomonas aeruginosa UCR-2957, resulting in greatest adsorption at pH 4.5 and a residence time of 100 minutes. Biosorption isotherms showed that the process follows the Langmuir model. The maximum adsorption rates (Nmax were 8.8 and 5.7 mg·g-1 for A. baumannii and P. aeruginosa, respectively; however, affinity constants suggest that P. aeruginosa (K=1.28 has higher affinity for nickel than A. baumannii (K=0.68. It is suggested that both strains could be used for wastewater treatment, as long as the concentration of Ni2+ is within the range of mg·L-1.Foi avaliada a capacidade de adsorção do Ni2+ por duas bactérias, Acinetobacter baumannii e Pseudomonas aeruginosa, em pH 4.5 com tempo de contato de 100 minutos. Isotermas de adsorção foram calculadas com as duas linhagens. Observou-se que, para ambas, o processo de adsorção está de acordo com o modelo fisicoquímico de Langmuir. A captação máxima do Ni2+ (Nmax foi 5.7 e 8.8 mg Ni2+ g-1 para P. aeruginosa e A. baumannii, respectivamente. Não obstante, P. aeruginosa apresenta uma constante de afinidade (K=1.28 maior que A. baumannii (K=0.68. Estes resultados indicam que ambas as linhagens são adequadas para o tratamento de águas contaminadas, desde que a concentração de níquel seja da ordem de mg·L-1.

  16. Evaluation of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry-Based VITEK MS System for the Identification of Acinetobacter Species from Blood Cultures: Comparison with VITEK 2 and MicroScan Systems

    Lee, Seung Yeob; Shin, Jong Hee; Kim, Soo Hyun; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook

    2014-01-01

    Background Acinetobacter species are the leading cause of bloodstream infection (BSI), but their correct identification is challenging. We evaluated the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based VITEK MS (bioMérieux, France), and two automated systems, VITEK 2 (bioMérieux) and MicroScan (Siemens, USA) for identification of Acinetobacter BSI isolates. Methods A total of 187 BSI isolates recovered at a university hospital in Korea between ...

  17. Genome Sequence of a Clinical Strain of Acinetobacter baumannii Belonging to the ST79/PFGE-HUI-1 Clone Lacking the AdeABC (Resistance-Nodulation-Cell Division-Type) Efflux Pump.

    López, M; Álvarez-Fraga, L; Gato, E; Blasco, L; Poza, M; Fernández-García, L; Bou, G; Tomás, M

    2016-01-01

    Increased expression of chromosomal genes for resistance-nodulation-cell division-type efflux systems plays a major role in the multidrug resistance of Acinetobacter baumannii Little is known about the genetic characteristics of clinical strains of Acinetobacter baumannii lacking the AdeABC pump. In this study, we sequenced the genome of clinical strain Ab421 GEIH-2010 (belonging to clone ST79/PFGE-HUI-1 from the GEIH-REIPI Ab. 2010 project) which lacks this efflux pump. PMID:27609928

  18. Clinical validation of a real-time polymerase chain reaction assay for rapid detection of Acinetobacter baumannii colonization.

    Blanco-Lobo, P; González-Galán, V; García-Quintanilla, M; Valencia, R; Cazalla, A; Martín, C; Alonso, I; Pérez-Romero, P; Cisneros, J M; Aznar, J; McConnell, M J

    2016-09-01

    Real-time polymerase chain reaction (PCR)-based approaches have not been assessed in terms of their ability to detect patients colonized by Acinetobacter baumannii during active surveillance. This prospective, double-blind study demonstrated that a real-time PCR assay had high sensitivity (100%) and specificity (91.2%) compared with conventional culture for detecting A. baumannii in 397 active surveillance samples, and provided results within 3h. Receiver-operator curve analyses demonstrated that the technique has diagnostic accuracy of 97.7% (95% confidence interval 96.0-99.3%). This method could facilitate the rapid implementation of infection control measures for preventing the transmission of A. baumannii. PMID:27206968

  19. Draft genome sequence of a multidrug-resistant blaOXA-23-producing Acinetobacter baumannii ST208 isolate from China.

    Chen, Yan; Wu, Liyan; Chen, Yu; Xu, Zhijun; Xu, Liqun

    2016-03-01

    Acinetobacter baumannii has emerged worldwide as an important opportunistic nosocomial pathogen and has become a major public health concern. In this study, the draft genome sequence of A. baumannii TCM331 (ST208/CC92), a multidrug-resistant (MDR) isolate harbouring the blaOXA-23 gene isolated in China, was determined. The genome of TCM331 was sequenced via Illumina HiSeq™ 2000, and bioinformatics analysis was performed. Important antimicrobial resistance determinants were observed in an estimated genome size of 4,058,691bp with 3838 predicted coding regions. In conclusion, these data might facilitate further understanding of the specific genomic features of MDR A. baumannii in China. PMID:27436391

  20. Antibiogram of multidrug resistant Acinetobacter baumannii isolated from clinical specimens at King Hussein Medical Centre, Jordan: a retrospective analysis.

    Batarseh, A; Al-Sarhan, A; Maayteh, M; Al-Khatirei, S; Alarmouti, M

    2016-11-01

    This study was conducted to determine the prevalence and the local antibiogram of multidrug-resistant Acinetobacter baumannii isolates in Al-Hussein Hospital at King Hussein Medical Centre in Amman, Jordan. In a retrospective study from January to December 2013, data on 116 non-repetitive positive clinical samples were retrieved from patients' laboratory records. The resistance rates of A. baumannii isolates were high for ceftriaxone, cefotaxime and ticarcillin (100%), ceftazidime, cefepime and piperacillin (98.3%), imipenem (97.4%), piperacillin/tazobactam (96.6%), quinolones (94.8%), ampicillin/sulbactam (89.7%), gentamicin, (87.9%), tobramycin and tetracycline (76.7%) and trimethoprim/sulfamethoxazole (75.9%), but lower for minocycline (26.7%) and colistin (1.7%). A. baumannii in our hospital were highly resistant to all antibiotics, including tigecycline, except for minocycline and colistin which are considered the last resort treatment for multidrug-resistant A. baumannii. PMID:26857720

  1. Abrp, a new gene, confers reduced susceptibility to tetracycline, glycylcine, chloramphenicol and fosfomycin classes in Acinetobacter baumannii.

    Li, X; Quan, J; Yang, Y; Ji, J; Liu, L; Fu, Y; Hua, X; Chen, Y; Pi, B; Jiang, Y; Yu, Y

    2016-08-01

    Acinetobacter baumannii, a non-fermenting gram-negative coccobacillus, is a major pathogen responsible for a variety of healthcare-associated infections, including pneumonia, urinary tract and bloodstream infections. Moreover, A. baumannii is associated with alarming increases in drug resistance rates to almost all available antibiotics leaving limited treatment options. Here, we characterize the biological functions of a novel gene, abrp, which encodes a peptidase C13 family. We demonstrate that the abrp is associated with decreased susceptibility to tetracycline, minocycline, doxycycline, tigecycline, chloramphenicol and fosfomycin. Deletion of abrp was able to increase cell membrane permeability and display slower cell growth rate. Results from the present study show that abrp plays an important role in conferring reduced susceptibility to different classes of antibiotics and cell growth in A. baumannii. The change of antibiotic sensitivities may result from modifications to the cell membrane permeability of A. baumannii. PMID:27220329

  2. In vitro synergy of colistin combinations against extensively drug-resistant Acinetobacter baumannii producing OXA-23 carbapenemase.

    Wei, Wenjuan; Yang, Haifei; Liu, Yanyan; Ye, Ying; Li, Jiabin

    2016-06-01

    Fifty extensively drug-resistant Acinetobacter baumannii (XDRAB) were isolated from patients. The chequerboard microdilution method was used to determine the in vitro activities of five colistin (COL)-based combinations including COL+fosfomycin (FOS), COL+rifampicin (RIF), COL+imipenem (IMP), COL+sulbactam (SUP) and COL+levofloxacin (LVX). The synergistic activity was evaluated by the fractional inhibitory concentration index (FICI). According to our results, the combination of COL was synergistic with FOS, RIF, IMP, SUP and LVX with the ratios of 50, 72, 88, 92 and 64%, respectively. When combined with COL, the other five agents showed increased antimicrobial activities. In addition, two of the combinations, COL+RIF and COL+IMP, were more active than the combinations of COL+FOS, COL+SUP and COL+LVX. More importantly, these combination regimens could exert synergistic effects at the sub-minimum inhibitory concentration (MIC) levels against XDRAB strains. PMID:25978105

  3. Plant growth-promoting and rhizosphere-competent Acinetobacter rhizosphaerae strain BIHB 723 from the cold deserts of the Himalayas.

    Gulati, Arvind; Vyas, Pratibha; Rahi, Praveen; Kasana, Ramesh Chand

    2009-04-01

    A phosphate-solubilizing bacterial strain BIHB 723 isolated from the rhizosphere of Hippophae rhamnoides was identified as Acinetobacter rhizosphaerae on the basis of phenotypic characteristics, carbon source utilization pattern, fatty acid methyl esters analysis, and 16S rRNA gene sequence. The strain exhibited the plant growth-promoting attributes of inorganic and organic phosphate solubilization, auxin production, 1-aminocyclopropane-1-carboxylate deaminase activity, ammonia generation, and siderophore production. A significant increase in the growth of pea, chickpea, maize, and barley was recorded for inoculations under controlled conditions. Field testing with the pea also showed a significant increment in plant growth and yield. The rifampicin mutant of the bacterial strain effectively colonized the pea rhizosphere without adversely affecting the resident microbial populations. PMID:19137371

  4. Complete genome of the multidrug-resistant Acinetobacter baumannii strain KBN10P02143 isolated from Korea

    Lee, Yong-Woon; Choe, Hanna; Lee, Sang-Heon; Kim, Kyung Mo; Kam, Sin; Kim, Byung Kwon; Lee, Won-Kil

    2016-01-01

    Acinetobacter baumannii, a strictly aerobic, non-fermentative, Gram-negative coccobacillary rod-shaped bacterium, is an opportunistic pathogen in humans. We recently isolated a multidrug-resistant A. baumannii strain KBN10P02143 from the pus sample drawn from a surgical patient in South Korea. We report the complete genome of this strain, which consists of 4,139,396 bp (G + C content, 39.08%) with 3,868 protein-coding genes, 73 tRNAs and six rRNA operons. Identification of the genes related to multidrug resistance from this genome and the discovery of a novel conjugative plasmid will increase our understanding of the pathogenicity associated with this species. PMID:27143492

  5. Molecular Identification and Antimicrobial Resistance Profile of Acinetobacter baumannii Isolated From Nosocomial Infections of a Teaching Hospital in Isfahan, Iran

    Fazeli

    2014-10-01

    Full Text Available Background Multidrug resistant (MDR and extensively drug resistant (XDR Acinetobacter baumannii are among important causes of nosocomial infections and cause therapeutic problems worldwide. The emergence of extensively drug-resistant A. baumannii (XDRAB cause serious threats to hospital acquired infections (HAI worldwide and further limit the treatment options. Objectives The current study aimed to identify and isolate the MDR and XDR Acinetobacter baumannii from different wards of a teaching hospital in Isfahan, Iran, and determine the susceptibility pattern of these bacteria. Materials and Methods One hundred and twenty one (121 isolates of A. baumannii collected from a teaching hospital in Isfahan, Iran, within eight months (between September 2013 and April 2014 were included in the current study. The samples were isolated from different wards and different specimens. To confirm the species of A. baumannii, Polymerase chain reaction (PCRwas conducted to identify blaoxa-51 gene. Disk diffusion method was employed to evaluate antimicrobial susceptibility against cefotaxime, ceftriaxone, ampicillin-sulbactam, cefepime, meropenem, tobramycin, amikacin, tetracycline, ciprofloxacin, trimethoprim- sulfamethoxazole, and aztreonam. Results Among the 121 isolated A. baumannii, 44% and 56% were isolated from female and male, respectively. Samples cultured from the trachea (36%, urine (15%, blood (10%, wound (10%, cerebrospinal fluid (7%, bronchial (4% and the others (18%. Most of the isolates (50% were obtained from intensive care unit (ICU. Isolated A. baumannii showed high resistance to the evaluated antibiotics except ampicillin-sulbactam, which showed only 33.9% resistance. Also, 62.8% and 100% of the isolates were identified as XDR and MDR. Conclusions The result of the current study showed the growing number of nosocomial infections associated with XDR A. baumannii causing difficulties in antibiotic therapy. Resistant strains increasingly cause

  6. Diversity in the major polysaccharide antigen of Acinetobacter baumannii assessed by DNA sequencing, and development of a molecular serotyping scheme.

    Dalong Hu

    Full Text Available We have sequenced the gene clusters for type strains of the Acinetobacter baumannii serotyping scheme developed in the 1990s, and used the sequences to better understand diversity in surface polysaccharides of the genus. We obtained genome sequences for 27 available serovar type strains, and identified 25 polysaccharide gene cluster sequences. There are structures for 12 of these polysaccharides, and in general the genes present are appropriate to the structure where known. This greatly facilitates interpretation. We also find 53 different glycosyltransferase genes, and for 7 strains can provisionally allocate specific genes to all linkages. We identified primers that will distinguish the 25 sequence forms by PCR or microarray, or alternatively the genes can be used to determine serotype by "molecular serology". We applied the latter to 190 Acinetobacter genome-derived gene-clusters, and found 76 that have one of the 25 gene-cluster forms. We also found novel gene clusters and added 52 new gene-cluster sequence forms with different wzy genes and different gene contents. Altogether, the strains that have one of the original 25 sequence forms include 98 A. baumannii (24 from our strains and 5 A. nosocomialis (3 from our strains, whereas 32 genomes from 12 species other than A. baumannii or A. nosocomialis, all have new sequence forms. One of the 25 serovar type sequences is found to be in European clone I (EC I, 2 are in EC II but none in EC III. The public genome strains add an additional 52 new sequence forms, and also bring the number found in EC I to 5, in EC II to 9 and in EC III to 2.

  7. High prevalence of extensively drug-resistant and metallo beta-lactamase-producing clinical Acinetobacter baumannii in Iran.

    Maspi, Hossein; Mahmoodzadeh Hosseini, Hamideh; Amin, Mohsen; Imani Fooladi, Abbas Ali

    2016-09-01

    Acinetobacter species particularly Acinetobacter baumannii (A. baumannii) have been widely reported as broad-spectrum antibiotic resistant pathogens. Expression of various types of metallo beta-lactamases (MBL), classified as Ambler class B, has been associated with carbapenem resistance. Here, we attempted to assess the frequency of extensively drug-resistant (XDR) and MBL-producing A. baumannii among clinical isolates. 86 clinical A. baumannii strains were collected from 2014 to 2015 and their susceptibility to meropenem (10 μg), imipenem (10 μg), azteronem (30 μg), pipracillin (100 μg) tazobactam (110 μg), tobramycin (10 μg), fosfomycin (200 μg), rifampicin (5 μg), colistin (10 μg), tigecycline (15 μg), sulbactam/ampicillin (10 μg + 10 μg) and polymixin B (300 U) was evaluated using disk diffusion method. The MBL-producing isolates were screened using combined disc diffusion method. Furthermore, the presence of blaVIM, blaIMP, blaSPM, blaGIM, blaSIM and blaNDM was detected by PCR. 34.9% of isolates were recovered from bronchoalveolar lavage (BAL). 81 (94.2%) and 62 (71.2%) isolates were multidrug resistance (MDR) and XDR, respectively. 44 (51.2%) and 65 (75.6%) isolates were MBL-producing strains with resistance to imipenem and meropenem, respectively. 2 (2.3%), 13 (15.1%), 2 (2.3%), 4 (4.7%) and 2 (2.3%) isolates carried blaVIM, blaIMP, blaSPM, blaGIM and blaSIM genes, respectively. Our data showed that the rate of XDR and MBL A. baumannii is on the rise. PMID:27448835

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

    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

  9. PATTERN OF ANTIMICROBIAL RESISTANCE IN CLINICAL ISO LATES OF ACINETOBACTER SPECIES AT A TERTIARY LEVEL HEALTH CA RE FACILITY IN NORTHERN INDIA

    Pooja

    2013-01-01

    Full Text Available ABSTRACT: BACKGROUND: Multi drug resistant Acinetobacter species is a rapi dly emerging pathogen in health care settings and has limited the options for effective treatment. It is increasingly reported as the cause of outbreaks and nosocomial infections such as blood-stream infections, ventilator-associated pneumonia, urinary tract infections and wound infections. AIM: The present study was undertaken to isolate and iden tify the multi drug resistant (MDR and extensively drug resistant (XDR Acinetobacter speci es. DESIGN AND SETTINGS: This is a prospective study conducted over a period of two years (September 2009 to August 2011 in a tertiary care hospital. Clinical samples were collect ed from both indoor and outdoor patients, irrespective of age and sex. MATERIALS AND METHODS: Three hundred non duplicate clinical isolates of Acinetobacter species were processed for species identification by standard Microbiological procedures. Antimicrobial susceptibil ity of these isolates was performed by Kirby-Bauer disc diffusion method. RESULTS: Of the 300 isolates, 224 (74.6% were identified as A. baumannii followed by A. lwoffii 73/300 (24.3 % and A. haemolyticus 3/300 (1%. Majority of the isolates were recovered from ICU pat ients 183/300 (61%, followed by patients admitted in wards 93/300 (31% and 24/300 (8% isol ates were from outdoor patients. Out of 300, 153 (51% isolates were XDR and 11% were MDR. Only about 10% of the isolates were sensitive to β-lactams and 30-40% of the strains we re sensitive to aminoglycosides and fluoroquinolones. None of the isolate was resistant to cefoperazone sulbactam, ceftriaxone sulbactam and polymyxins. Statistically significant difference (p value <0.001 was noticed between antibiotic resistance of A. baumannii and A . lwoffii. CONCLUSION: The increasing trends towards antibiotic resistance reflect the ex tensive use of antibiotics in hospitals which in turn exerts selective pressure on Acinetobacter in h ospital

  10. 鲍曼不动杆菌感染的高危因素的分析%The risk factors for nosocomial infection caused by Acinetobacter baumanii

    张玲; 欧阳玲; 尚碧莲; 孙光伟; 邸玥莹; 马莉; 王厚照

    2011-01-01

    Objective To analyze the risk factors for nosocomial infection caused by Acinetobacter baumanii in our hospital. Methods 187 patients clinical data infected by Acinetobacter baumanii from January to December in 2010 in our hospital were collected, and the risk factors for nosocomial infection caused by Acinetobacter baumanii were analyzed by muti-factor logistic regression analysis. Results Ventilator applied, intensive care unit(ICU)stay, previous use of third generation cephalosporin antibiotics and indwelling catheter were independent risk factors for nosocomial infection caused by Acinetobacter baumanii[odd ratios(OR) = 39. 242,19. 651,4. 534 ,3. 439 ,P<0. 01]. Conclusion It is important to prevent nosocomial infection caused by Acinetobacter baumanii by strict limitation on the indication of ICU stay,the use of ventilator,third generation cephalosporin antibiotics and indwelling catheter,and target monitoring of nosocomial infection caused by Acinetobacter baumanii in our hospital should be strengthened.%目的 对该院鲍曼不动杆菌(Ab)感染的危险因素进行分析.方法 收集2010年1~12月该院187例感染Ab住院患者的临床资料,采用多因素logistic回归方法 分析感染Ab的危险因素.结果 使用呼吸机、入住ICU、前期大量使用3代头孢和泌尿道插管是Ab感染的独立危险因素(比值比分别为39.242、19.651、4.534、3.439,P<0.05).结论 严格把握入住ICU、前期3代头孢大量使用、呼吸机及泌尿道插管的使用,及时进行医院感染的检测,对控制Ab所引发的医院感染具有突出的临床意义.

  11. Potensi Tanaman Ornamental (Aglaonema sp., Dieffenbachia sp., dan Spathiphyllum sp.) dalam Menurunkan Jumlah Mikroba Udara dalam Ruangan Kelas Sekolah Dasar

    Mangunsong, Sisca Nency Teresia

    2016-01-01

    Bioaerosol is dust particles consisting of bacteria and other fungi with spores that are in the room when the temperature and humidity level are adequate. Its presence in the room are generally harmless, but some time causes disease. This research was aims to determine the effect of ornamental plant Aglaonema sp., Dieffenbachia sp., and Spathiphyllum sp. on amount of bacteria and fungi in the class room. Bioaerosol isolation was performed according to the method of air sampling with three rep...

  12. Sebaran dan Kerapatan Populasi Pratylenchus sp dan Radopholus sp Pada Tanaman Kopi (Coffea sp.) Kabupaten Gayo Lues Provinsi Aceh

    Bayhaqi

    2015-01-01

    Bayhaqi, 2014. Distribution and Population Density Of Pratylenchus sp and Radopholus sp on Coffee (Coffea sp.) in Gayo Lues Regency Aceh Province. Under supervising commission Darma Bakti and Hasanuddin. Gayo Coffee is one among the main export commodities of Indonesia has been known in the domestic and international markets, Gayo coffee production includes more than 90% of the total coffee production in the province. Coffee production in Gayo Lues district reached 540 kg / ha with a pla...

  13. DISTRIBUSI Solen sp DI PERAIRAN KABUPATEN BANGKALAN

    Eva Ari Wahyuni

    2016-03-01

    Full Text Available DISTRIBUTION OF Solen sp IN BANGKALAN WATERSSolen sp potential needs to be developed on the island of Madura, particularly in Bangkalan. Solen sp utilization has increased which has the potential to overfishing. Therefore, this study aims to determine the density of Solen sp and their ecology in the waters Modung village, Modung District, Bangkalan. The experiment was conducted in April 2015 using the descriptive method. The materials used include Solen sp and physico-chemical parameters of the environment (temperature, salinity, pH, and substrate. The analyzes were conducted at the Laboratory of Marine Science, Department of Marine Sciences, Trunojoyo University of Madura by using the tool grabsampler, sieveshaker, and pipetting with gravimetric method. The analysis shows the range of values of temperature between 29-300C, salinity between 31-32 ppt, pH were 7.9-8.0 and the type of substrate in the form of sandy mud, as well as the density of Solen sp from 8-10 individuals/m2. All measurement results indicate normal conditions and in accordance with the sea water quality standard for marine life, which can be a suitable habitat for the growth and development of Solen sp. This condition is thought to affect the density of Solen sp.Keywords: Bangkalan, density, distribution, Solen sp, substrate.ABSTRAKPotensi Solen sp perlu dikembangkan di pulau Madura, khususnya di Kabupaten Bangkalan. Pemanfaatan Solen sp mengalami peningkatan sehingga berpotensi overfishing. Untuk itu, penelitian ini bertujuan untuk mengetahui kepadatan Solen sp dan ekologinya di perairan desa Modung, Kecamatan Modung, Kabupaten Bangkalan. Penelitian dilaksanakan pada bulan April 2015 dengan metode deskriptif. Materi dan bahan yang digunakan diantaranya Solen sp dan parameter fisika-kimia lingkungan (suhu, salinitas, pH, dan substrat. Analisa dilakukan di Laboratorium Ilmu Kelautan, Program studi/Jurusan Ilmu Kelautan Universitas Trunojoyo Madura dengan menggunakan alat

  14. Fungi Association with Cedar’s Seeds and Fusarium sp. and Pestalotia sp. Pathogenicities Levantamento de Fungos em Sementes de Cedro e Avaliação da Patogenicidade de Fusarium sp. e Pestalotia sp.

    Sílvia Cristina Benetti

    2010-02-01

    Full Text Available

    This research had as main objectives the evaluation of cedar’s seeds seed-borne fungi and the Fusarium
    sp. and Pestalotia sp. pathogenicities. For the fungi detection Potato Dextrose and Agar medium and Blotter
    test methods were used. For the pathogenicity tests, isolates of Fusarium sp. and Pestalotia sp. were used. The following fungi were observed: Pestalotia sp., Fusarium sp., Phomopsis sp., Colletotrichum sp., Macrophomina sp. and Cladosporium sp. The fungi observed in the highest frequencies were: Fusarium sp., Phomopsis sp. and Pestalotia sp. A reduction of the germination level was observed in seedlings from cedar’s seed inoculated with Fusarium sp.

     

    doi: 10.4336/2009.pfb.58.81

    Este trabalho teve por objetivos avaliar fungos em sementes de cedro e testar a patogenicidade de Fusarium sp. e Pestalotia sp. Para detecção de fungos, foram utilizados batata-dextrose-ágar e papel filtro. Para o teste de patogenicidade, utilizaram-se isolados de Fusarium sp. e de Pestalotia sp. Foi constatada a presença dos seguintes fungos nas sementes: Pestalotia sp., Fusarium sp., Phomopsis sp., Colletotrichum sp., Macrophomina sp. e Cladosporium sp. Os fungos de maior freqüência foram: Fusarium sp., Phomopsis sp. e Pestalotia sp. Observou-se decréscimo nos valores de emergência das plântulas oriundas das sementes inoculadas com Fusarium sp.

     

    Doi: 10.4336/2009.pfb.58.81

  15. Acinetobacter spp. e Pseudomonas aeruginosa resistentes aos carbapenêmicos no Hospital Universitário de Santa Maria, Rio Grande do Sul =Carbapenem-resistant Acinetobacter spp. and Pseudomonas aeruginosa at the University Hospital of Santa Maria, Rio Grande do Sul state, Brazil

    Brezolin, Daiane

    2014-01-01

    Conclusões: Neste estudo Acinetobacter spp. e P. aeruginosa apresentaram elevada resistência aos antimicrobianos. A polimixina B mostrou-se um bom antimicrobiano para o tratamento de infecções por microrganismos resistentes aos carbapenêmicos neste nosocômio.

  16. Draft genome sequence of a multidrug-resistant New Delhi metallo-β-lactamase NDM-1-producing Acinetobacter pittii sequence type 207 isolate from China.

    Wang, Jianfeng; Wu, Liyan; Xu, Liqun; Chen, Yu; Chen, Yan

    2016-09-01

    The increasing emergence of carbapenem-resistant Acinetobacter spp. worldwide has resulted in the limited availability of effective antimicrobial agents and has become a major public health concern. In this study, the draft genome sequence of Acinetobacter pittii TCM292 belonging to sequence type 207 (ST207), a multidrug-resistant (MDR) isolate harbouring the New Delhi metallo-β-lactamase blaNDM-1 gene, was determined using an Illumina HiSeq™ 2000 platform. The genome sequence was analysed by bioinformatics methods. The A. pittii TCM292 genome size was estimated to be 3791758bp with 3486 predicted coding regions. These data might facilitate further understanding of the specific genomic features of MDR A. pittii in China. PMID:27530847

  17. First Preliminary Report on Isolation and Characterization of Novel Acinetobacter spp. in Casing Soil Used for Cultivation of Button Mushroom, Agaricus bisporus (Lange Imbach

    D. K. Choudhary

    2011-01-01

    Full Text Available Despite evaluation of large number of agroindustrial wastes for their use as casing material for Agaricus bisporus (Lange Imbach cultivation, scant attention has been given to the importance of biological properties of casing materials. In the present study, an attempt was made to characterize the bacterial flora in casing layer, namely, Farm Yard Manure (FYM and Spent Mushroom Substrate/spent compost (SMS/SC (FYM+SC, 3 : 1 and FYM and Vermi Compost (VC (FYM+VC, 3 : 1, employing partial 16S rDNA sequencing. Available data showed a significant variety of organisms that included Acinetobacter and Pseudomonas of the γ-proteobacteria, that were the most frequently encountered genera. This is the first preliminary report on the microbial diversity of casing soils and demonstrates the presence of Acinetobacter spp. that has not been previously described in casing material.

  18. Research advance in clinical multi-drug resistant Acinetobacter baumannii%临床多重耐药鲍曼不动杆菌的研究进展

    陆坤; 胡志东

    2013-01-01

    随着新型广谱抗菌药物的广泛应用,鲍曼不动杆菌的耐药率逐年升高,多重耐药甚至泛耐药鲍曼不动杆菌的临床分离率明显增高.此文对近年来国内外多重耐药鲍曼不动杆菌感染的耐药机制、分型检测方法及临床治疗作一综述.%With the extensive use of new broad-spectrum antibiotics,the resistant rate of Acinetobacter baumannii has increased gradually.While the clinical isolates of multi-drug resistant and pan-resistant Acinetobacter baumanniihave also increased significantly.In this review,the resistant mechanisms,typing methods and treatment of multi-drug resistant A cinetobacter baumanii are summarized.

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

    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.

  20. Pharmacodynamics of the Antibacterial Effect of and Emergence of Resistance to Doripenem in Pseudomonas aeruginosa and Acinetobacter baumannii in an In Vitro Pharmacokinetic Model

    Bowker, Karen E.; Noel, Alan R.; Tomaselli, Sharon G.; Elliott, Heather; MacGowan, Alasdair P.

    2012-01-01

    An in vitro dilutional pharmacokinetic model of infection was used to study the pharmacodynamics of doripenem in terms of the ability to kill Pseudomonas aeruginosa or Acinetobacter baumannii and also changes in their population profiles. In dose-ranging studies, the cumulative percentages of a 24-h period that the drug concentration exceeds the MIC under steady-state pharmacokinetic conditions (TMICs) required for doripenem to produce a 24-h bacteriostatic effect and a −2-log-unit reduction ...

  1. The influence of carbon sources on the expression of the recA gene and genotoxicity detection by an Acinetobacter bioreporter.

    Jiang, Bo; Song, Yizhi; Zhang, Dayi; Huang, Wei E; Zhang, Xu; Li, Guanghe

    2015-04-01

    Bacterial whole-cell bioreporters are practical and reliable analytical tools to assess the toxicity and bioavailability of environmental contaminants, yet evidence has shown that their performance could be affected by different carbon sources. This paper evaluated the influence of carbon sources on the recA gene (ACIAD1385) in a DNA damage-inducible recA::luxCDABE Acinetobacter bioreporter and optimized the induction conditions for its practical application in environmental monitoring. Different carbon sources, including LB, potassium acetate (MMA), sodium citrate (MMC), sodium pyruvate (MMP), and sodium succinate (MMS), significantly influenced (p < 0.05) the bioluminescence intensity of the genotoxicity bioreporter. A reverse transcription quantitative PCR (RT-qPCR) showed the different expression levels of the DNA damage-inducible gene recA (p < 0.05), suggesting that carbon sources influenced the DNA damage response in the Acinetobacter bioreporter at the transcriptional level. Additionally, proteomic analysis identified 122 proteins that were differentially expressed after exposure to mitomycin C in defined media and LB, and 5 of them were related to the DNA damage response, indicating the effects of carbon sources on the DNA damage response in Acinetobacter at the translational level. The repression effect caused by the rich medium, LB, was possibly related to the mechanism of carbon catabolite repression. Our results suggest that the practical application of Acinetobacter bioreporters to the genotoxicity assessment of polycyclic aromatic hydrocarbon (PAH)-contaminated soils could be significantly improved by using a standard medium of defined composition, as this could increase their sensitivity. PMID:25764502

  2. Effect of colistin exposure and growth phase on the surface properties of live Acinetobacter baumannii cells examined by atomic force microscopy

    Soon, Rachel L; Nation, Roger L; Harper, Marina; Adler, Ben; Boyce, John D.; Tan, Chun-Hong; Jian LI; Larson, Ian

    2011-01-01

    The diminishing antimicrobial development pipeline has forced the revival of colistin as a last line of defence against infections caused by multidrug-resistant Gram-negative ‘superbugs’ such as Acinetobacter baumannii. The complete loss of lipopolysaccharide (LPS) mediates colistin resistance in some A. baumannii strains. Atomic force microscopy was used to examine the surface properties of colistin-susceptible and -resistant A. baumannii strains at mid-logarithmic and stationary growth phas...

  3. Synergistic Activity of Colistin and Rifampin Combination against Multidrug-Resistant Acinetobacter baumannii in an In Vitro Pharmacokinetic/Pharmacodynamic Model

    Lee, Hee Ji; Bergen, Phillip J.; Bulitta, Jurgen B.; Tsuji, Brian; Forrest, Alan; Nation, Roger L; Jian LI

    2013-01-01

    Combination therapy may be required for multidrug-resistant (MDR) Acinetobacter baumannii. This study systematically investigated bacterial killing and emergence of colistin resistance with colistin and rifampin combinations against MDR A. baumannii. Studies were conducted over 72 h in an in vitro pharmacokinetic (PK)/pharmacodynamic (PD) model at inocula of ∼106 and ∼108 CFU/ml using two MDR clinical isolates of A. baumannii, FADDI-AB030 (colistin susceptible) and FADDI-AB156 (colistin resis...

  4. Atomic Force Microscopy Investigation of the Morphology and Topography of Colistin-Heteroresistant Acinetobacter baumannii Strains as a Function of Growth Phase and in Response to Colistin Treatment▿

    Soon, Rachel L; Nation, Roger L; Hartley, Patrick G.; Larson, Ian; Jian LI

    2009-01-01

    The prevalence of infections caused by multidrug-resistant gram-negative Acinetobacter baumannii strains and the lack of novel antibiotics under development are posing a global dilemma, forcing a resurgence of the last-line antibiotic colistin. Our aim was to use atomic force microscopy (AFM) to investigate the morphology and topography of paired colistin-susceptible and -resistant cells from colistin-heteroresistant A. baumannii strains as a function of bacterial growth phase and colistin ex...

  5. Activity of Cecropin A-Melittin Hybrid Peptides against Colistin-Resistant Clinical Strains of Acinetobacter baumannii: Molecular Basis for the Differential Mechanisms of Action

    Saugar, José María; Rodríguez-Hernández, María Jesús; de la Torre, Beatriz G.; Pachón-Ibañez, María Eugenia; Fernández-Reyes, María; Andreu, David; Pachón, Jerónimo; Rivas, Luis

    2006-01-01

    Acinetobacter baumannii has successfully developed resistance against all common antibiotics, including colistin (polymyxin E), the last universally active drug against this pathogen. The possible widespread distribution of colistin-resistant A. baumannii strains may create an alarming clinical situation. In a previous work, we reported differences in lethal mechanisms between polymyxin B (PXB) and the cecropin A-melittin (CA-M) hybrid peptide CA(1-8)M(1-18) (KWKLFKKIGIGAVLKVLTTGLPALIS-NH2) o...

  6. PATTERN OF ANTIMICROBIAL RESISTANCE IN CLINICAL ISO LATES OF ACINETOBACTER SPECIES AT A TERTIARY LEVEL HEALTH CA RE FACILITY IN NORTHERN INDIA

    Pooja; Rama,, M.; Antariksh; Seema; Uma

    2013-01-01

    ABSTRACT: BACKGROUND: Multi drug resistant Acinetobacter species is a rapi dly emerging pathogen in health care settings and has limited the options for effective treatment. It is increasingly reported as the cause of outbreaks and nosocomial infections such as blood-stream infections, ventilator-associated pneumonia, urinary tract infections and wound infections. AIM: The present study was undertaken to isolate and iden tify the multi drug resistant (MDR) and...

  7. Antibiotic Resistance and the Frequency of Extended-Spectrum B-Lactamase in Acinetobacter baumannii Isolated from Clinical Samples through Phenotypic Methods

    Somayeh Vafaei; Reza Mirnejad; Nour Amirmozafari; Abbasali Imani Fooladi; Faramarz Masjedian

    2013-01-01

    AbstractBackground and objectives: Nowadays Acinetobacter baumannii is as one of the problematic opportunistic pathogens, especially in intensive care because of the incidence of drug-resistant strains in the world. The purpose of current study was to define the antibiotic susceptibility patterns and detect the prevalence of producing strains of extended-spectrum β-lactamase (ESBL) in A. baumannii isolates which had been isolated from clinical samples with combined disk test.Materials and met...

  8. An Exocellular Protein from the Oil-Degrading Microbe Acinetobacter venetianus RAG-1 Enhances the Emulsifying Activity of the Polymeric Bioemulsifier Emulsan

    Bach, Horacio; Berdichevsky, Yevgeny; Gutnick, David

    2003-01-01

    The oil-degrading microorganism Acinetobacter venetianus RAG-1 produces an extracellular polyanionic, heteropolysaccharide bioemulsifier termed emulsan. Emulsan forms and stabilizes oil-water emulsions with a variety of hydrophobic substrates. Removal of the protein fraction yields a product, apoemulsan, which exhibits much lower emulsifying activity on hydrophobic substrates such as n-hexadecane. One of the key proteins associated with the emulsan complex is a cell surface esterase. The este...

  9. Draft Genome Sequence of Colistin-Resistant Acinetobacter baumannii Strain VB22595 Isolated from a Central Line-Associated Bloodstream Infection.

    Veeraraghavan, Balaji; Anandan, Shalini; Ragupathi, Naveen Kumar Devanga; Vijayakumar, Saranya; Sethuvel, Dhiviya Prabaa Muthuirulandi; Biswas, Indranil

    2016-01-01

    Acinetobacter baumannii is an important emerging pathogen that causes health care-associated infections. In this study, we determined the genome of a multidrug-resistant clinical strain, VB22595, isolated from a hospital in Southern India. The draft genome indicates that strain VB22595 encodes a genome of ~3.92 Mb in size and does not contain plasmid derived MCR-1 for colistin resistance. PMID:27516521

  10. Emergence of extensively drug-resistant Acinetobacter baumannii complex over 10 years: Nationwide data from the Taiwan Surveillance of Antimicrobial Resistance (TSAR) program

    Kuo Shu-Chen; Chang Shan-Chwen; Wang Hui-Ying; Lai Jui-Fen; Chen Pei-Chen; Shiau Yih-Ru; Huang I-Wen; Lauderdale Tsai-Ling

    2012-01-01

    Abstract Background Acinetobacter baumannii complex (ABC) has emerged as an important pathogen causing a variety of infections. Longitudinal multicenter surveillance data on ABC from different sources in Taiwan have not been published. Using data from the Taiwan Surveillance of Antimicrobial Resistance (TSAR) conducted biennially, we investigated the secular change in resistance of 1640 ABC from 2002 to 2010 (TSAR period III to VII) to different antimicrobial agents and identified factors ass...

  11. Molecular Characterization of the Gene Encoding a New AmpC β-Lactamase in a Clinical Strain of Acinetobacter Genomic Species 3

    Beceiro, Alejandro; Domínguez, Lourdes; Ribera, Anna; Vila, Jordi; Molina, Francisca; Villanueva, Rosa; Eiros Bouza, José María; Bou, German

    2004-01-01

    A presumptive chromosomal cephalosporinase (pI, 9.0) from a clinical strain of Acinetobacter genomic species 3 (AG3) is reported. The nucleotide sequence of this β-lactamase shows for the first time the gene encoding an AmpC enzyme in AG3. In addition, the biochemical properties of the novel AG3 AmpC β-lactamase are reported

  12. Genomic comparison of multi-drug resistant invasive and colonizing Acinetobacter baumannii isolated from diverse human body sites reveals genomic plasticity

    Hsiao William W; Phillippy Adam M; Harris Anthony D; Johnson J Kristie; Sahl Jason W; Thom Kerri A; Rasko David A

    2011-01-01

    Abstract Background Acinetobacter baumannii has recently emerged as a significant global pathogen, with a surprisingly rapid acquisition of antibiotic resistance and spread within hospitals and health care institutions. This study examines the genomic content of three A. baumannii strains isolated from distinct body sites. Isolates from blood, peri-anal, and wound sources were examined in an attempt to identify genetic features that could be correlated to each isolation source. Results Pulsed...

  13. Prevalence of class1, 2 and 3 integrons among extensive drug resistance Acinetobacter baumanii strains isolated from intensive care units in Hamadan, west province, Iran

    Fatemeh abestani, 1Mina Safari, 2Ghodratollah Roshanaii, 1Mohammad Yousef Alikhani Moammadi; Mohammad Reza Arabestani; Mina Safari; Ghodratollah Roshanaii; Mohammad Yousef Alikhani

    2014-01-01

    Background and Aim: Acinetobacter baumannii is opportunistic, gram negative, aerobic and nonfermentative coccobacilli. It is difficult to control and eradicate these bacteria, because of increased resistance to last-line antibiotic therapy and high peripheral resistance. The purpose of this study was to determine the prevalence of integron  and its relationship with the antibiotic resistance in A. baumannii. Materials and Methods: 100 isolates of A. baumannii were ...

  14. Association of Single Nucleotide Polymorphisms in Toll-like Recep¬tors with Acinetobacter baumanii Infectionin a Chinese Popu¬lation

    He, Lei; Maohu LIN; Fan, Wensheng; Liu, Yunxi; SUO, Jijiang; Xing, Yubin; Jia, Ning

    2016-01-01

    Background: During recent years, infection of Acinetobacter baumanii showed a rapid growth in hospitals and community. Toll-like receptors (TLRs) are the most important pattern recognition receptors, which play a critical role during recognizing invading pathogens by the natural immune system. Our objective was to determine the associations of TLRs polymorphisms with the susceptibility to A. baumanii infection in a Chinese population.Methods: We carried out a case-control study, genotyping 13...

  15. Triclosan Can Select for an AdeIJK-Overexpressing Mutant of Acinetobacter baumannii ATCC 17978 That Displays Reduced Susceptibility to Multiple Antibiotics

    Fernando, Dinesh M.; Xu, Wayne; Loewen, Peter C.; Zhanel, George G; Kumar, Ayush

    2014-01-01

    In order to determine if triclosan can select for mutants of Acinetobacter baumannii ATCC 17978 that display reduced susceptibilities to antibiotics, we isolated a triclosan-resistant mutant, A. baumannii AB042, by serial passaging of A. baumannii ATCC 17978 in growth medium supplemented with triclosan. The antimicrobial susceptibility of AB042 was analyzed by the 2-fold serial dilution method. Expression of five different resistance-nodulation-division (RND) pump-encoding genes (adeB, adeG, ...

  16. 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

    Pasanen, Tanja; Koskela, Suvi; Mero, Sointu; Tarkka, Eveliina; Tissari, Päivi; Vaara, Martti; Kirveskari, Juha

    2014-01-01

    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. PMID:24465749

  17. 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.

    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.

  18. Acinetobacter baumannii Infection in Prior ICU Bed Occupants Is an Independent Risk Factor for Subsequent Cases of Ventilator-Associated Pneumonia

    Eirini Tsakiridou

    2014-01-01

    Full Text Available Objective. We aimed to evaluate risk factors for ventilator-associated pneumonia (VAP due to Acinetobacter baumannii (AbVAP in critically ill patients. Methods. This was a prospective observational study conducted in an intensive care unit (ICU of a district hospital (6 beds. Consecutive patients were eligible for enrolment if they required mechanical ventilation for >48 hours and hospitalization for >72 hours. Clinical, microbiological, and laboratory parameters were assessed as risk factors for AbVAP by univariate and multivariate analysis. Results. 193 patients were included in the study. Overall, VAP incidence was 23.8% and AbVAP, 11.4%. Previous hospitalization of another patient with Acinetobacter baumannii infection was the only independent risk factor for AbVAP (OR (95% CI 12.016 (2.282–19.521 P<0.001. ICU stay (25±17 versus 12±9   P<0.001, the incidence of other infections (OR (95% CI 9.485 (1.640–10.466 P=0.002 (urinary tract infection, catheter related infection, and bacteremia, or sepsis (OR (95% CI 10.400 (3.749–10.466 P<0.001 were significantly increased in patients with AbVAP compared to patients without VAP; no difference was found with respect to ICU mortality. Conclusion. ICU admission or the hospitalization of patients infected by Acinetobacter baumannii increases the risk of AbVAP by subsequent patients.

  19. Babesia sp. in Colombian bats (Microchiroptera).

    Marinkelle, C J

    1996-07-01

    Two leaf-chinned bats (Mormoops megalophylla) collected in 1963 in central Colombia were heavily infected with Babesia sp., probably Babesia vesperuginis. Both bats had pronounced splenomegaly. This is the first report of a Babesia sp. infection of a bat in the Americas. PMID:8827683

  20. Glyphosate catabolism by Pseudomonas sp

    The pathway for the degradation of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. PG2982 has been determined using metabolic radiolabeling experiments. Radiorespirometry experiments utilizing [3-14C] glyphosate revealed that approximately 50-59% of the C3 carbon was oxidized to CO2. Fractionation of stationary phase cells labeled with [3-14C]glyphosate revealed that from 45-47% of the assimilated C3 carbon is distributed to proteins and that amino acids methionine and serine are highly labeled. The nucleic acid bases adenine and guanine received 90% of the C3 label that was incorporated into nucleic acids, and the only pyrimidine base labeled was thymine. Pulse labeling of PG2982 cells with [3-14C]glyphosate revealed that [3-14C]sarcosine is an intermediate in glyphosate degradation. Examination of crude extracts prepared from PG2982 cells revealed the presence of an enzyme that oxidizes sarcosine to glycine and formaldehyde. These results indicate that the first step in glyphosate degradation by PG2982 is cleavage of the carbon-phosphorus bond, resulting in the release of sarcosine and a phosphate group. The phosphate group is utilized as a source of phosphorus, and the sarcosine is degraded to glycine and formaldehyde. Phosphonate utilization by Pseudomonas sp. PG2982 was investigated. Each of the ten phosphonates tested were utilized as a sole source of phosphorus by PG2982. Representative compounds tested included alkylphosphonates, 1-amino-substituted alkylphosphonates, amino-terminal phosphonates, and an arylphosphonate. PG2982 cultures degraded phenylphosphonate to benzene and produced methane from methylphosphonate. The data indicate that PG2982 is capable of cleaving the carbon-phosphorus bond of several structurally different phosphonates

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

    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.

  2. Predictive value of Sp1/Sp3/FLIP signature for prostate cancer recurrence.

    Roble G Bedolla

    Full Text Available Prediction of prostate cancer prognosis is challenging and predictive biomarkers of recurrence remain elusive. Although prostate specific antigen (PSA has high sensitivity (90% at a PSA level of 4.0 ng/mL, its low specificity leads to many false positive results and considerable overtreatment of patients and its performance at lower ranges is poor. Given the histopathological and molecular heterogeneity of prostate cancer, we propose that a panel of markers will be a better tool than a single marker. We tested a panel of markers composed of the anti-apoptotic protein FLIP and its transcriptional regulators Sp1 and Sp3 using prostate tissues from 64 patients with recurrent and non-recurrent cancer who underwent radical prostatectomy as primary treatment for prostate cancer and were followed with PSA measurements for at least 5 years. Immunohistochemical staining for Sp1, Sp3, and FLIP was performed on these tissues and scored based on the proportion and intensity of staining. The predictive value of the FLIP/Sp1/Sp3 signature for clinical outcome (recurrence vs. non-recurrence was explored with logistic regression, and combinations of FLIP/Sp1/Sp3 and Gleason score were analyzed with a stepwise (backward and forward logistic model. The discrimination of the markers was identified by sensitivity-specificity analysis and the diagnostic value of FLIP/Sp1/Sp3 was determined using area under the curve (AUC for receiver operator characteristic curves. The AUCs for FLIP, Sp1, Sp3, and Gleason score for predicting PSA failure and non-failure were 0.71, 0.66, 0.68, and 0.76, respectively. However, this increased to 0.93 when combined. Thus, the "biomarker signature" of FLIP/Sp1/Sp3 combined with Gleason score predicted disease recurrence and stratified patients who are likely to benefit from more aggressive treatment.

  3. 鲍曼不动杆菌107株感染的分布与耐药性%Acinetobacter baumannii infection in 107 tribution and drug resistance

    马艳; 李俊伟; 翟金翎; 吴莉

    2009-01-01

    目的 分析鲍曼不动杆菌的标本来源、分布及耐药变迁趋势,为有效预防控制感染、指导临床合理用药提供依据.方法 采用VTTEK-32型自动微生物鉴定/药敏分析系统进行菌株鉴定及药物敏感性测试,耐药性数据分析采用WHONET5软件.结果 3年间分离出107株鲍曼不动杆菌,其对12种抗菌药物活性较好的是亚胺培南、阿米卡星、氨苄西林/舒巴坦,耐药率为0.9%、5.6%、6.5%;耐药率较高的是氨苄西林74.8%、头孢曲松钠63.6%、头孢噻肟钠38.3%,氨曲南25.2%.2008年与2006和2007年相比较,鲍曼不动杆菌的耐药率均有逐年上升的趋势.结论 本院监测结果显示鲍曼不动杆菌对碳青霉烯类、氨基糖苷类、β-内酰胺酶抑制剂复合药物保持较好的敏感性,但鲍曼不动杆菌临床分布逐年增加,耐药率逐渐上升.%Objective To investigate the variations of tendency of drug-resistance from Jan 2006 to Dec 2008. the origin and the distributing of Acinetobacter baumannii and provide basis for selection of clinical drugs.Methods The characteriztion and sensitivity to antibiotics of Acinetobacter baumannii were analysed using VTTEK-32 system.Results 107 strains of Acinetobacter baumannii were separated and characterized during the three years.The rates of resistance to antibiotics were Imipenem 0.9%,Amikacin 5.6%,Ampicillin/Sulbactam 6.5%,Ampicillin 74.8% Ceftriaone 63.6%,Cefotaxime 38.3%,Aztreonam 25.2%.The resistance rate of Acinetobacter baumanii increased from 2006 to 2008,showed increasing tendency.Conclusion Acinetobacter baumannii showed good sensitivity to Carbapenems,Aminoglycosides,β-lactam antibiotics,Acinetobacter baumanii are widely distributing in hospital and are widely resistant to many kinds of antibiotics,The results suggested that the resistance of Acinetobacter baumannii to antibiotics should be continuously monitored,it will be beneficial for infection-control to collect antibiotics basing on the

  4. 重症监护病房鲍曼不动杆菌耐药性分析%Antibiotics resistance of Acinetobacter baumannii in intensive care unit

    邓健康; 郭晓兰

    2015-01-01

    Objective To investigate the specimen source and antibiotics resistance of Acinetobacter baumannii isolated from in‐patient in Intensive Care Unit(ICU) .Methods Specimen source and antibiotics resistance of 520 strains of Acinetobacter bauman‐nii ,isolated from patients of ICU in Affiliated Hospital of North Sichuan Medical College from 2011 to 2014 ,were retrospectively analyzed .Results The main source of Acinetobacter baumannii was sputum specimens ,accounting for 90 .4% .Acinetobacter bau‐mannii isolates showed the lowest resistance rates to cefoperazone‐sulbactam and minocycline(32 .0% and 25 .2% ,respectively) .A‐bout 68 .1% and 74 .9% of these strains were resistant to trimethoprim‐sulfamethoxazole and levofloxacin ,respectively .More than 86 .0% of the strains were resistant to other tested antibacterial agents .Conclusion Acinetobacter baumanii strains ,isolated from ICU ,could have high resistance rates to many kinds of antibacterial agents ,and cefoperazone‐sulbactam and minocycline might be with fine antibacterial activity against Acinetobacter baumanii .Drug resistance monitoring of Acinetobacter baumanii should be strengthened ,and antibacterial agents should be selected and used rationally according to the results of drug sensitivity test .%目的:了解分离自重症监护病房(IC U )送检标本鲍曼不动杆菌的标本来源和耐药性。方法回顾性分析2011~2014年分离自川北医学院附属医院IC U患者临床标本的520株鲍曼不动杆菌的临床分布和耐药性。结果鲍曼不动杆菌主要分离自痰液标本,占90.4%。鲍曼不动杆菌对头孢哌酮/舒巴坦和米诺环素的耐药率相对较低,分别为32.0%和25.2%;对复方磺胺甲噁唑和左旋氧氟沙星的耐药率分别为68.1%和74.9%;对其他常用抗菌药物的耐药率均超过86.0%。结论分离自IC U送检标本的鲍曼不动杆菌对多种抗菌药物耐药率高,对头孢哌酮/

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

    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.

  6. PENGARUH FILTRAT CENDAWAN Aspergillus sp. DAN Fusarium sp. TERHADAP VIABILITAS BENIH DAN PERTUMBUHAN BIBIT SENGON (Paraserianthes falcataria)

    Naning Yuniarti; Tati Suharti; Yulianti Bramasto

    2013-01-01

    Fungi are one of the main causes of damage to seeds. Fungi can be a pathogen or saprophyte such as Aspergillus sp. and Fusarium sp. The purpose of this study was to determine the effects of filtrate fungus Aspergillus sp and Fusarium sp on seed viability and seedling growth performance of Sengon (Paraserianthes falcataria). The experiment design used was the Completely Randomized Design (CRD), with treatment: control, filtrate of Aspergillus sp and Fusarium sp filtrate. Each treatment was rep...

  7. Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource

    Akanksha Srivastava; Ratnakar Tiwari; Vikas Srivastava; Tej Bali Singh; Ravi Kumar Asthana

    2015-01-01

    An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for ant...

  8. Sp1 regulates human huntingtin gene expression.

    Wang, Ruitao; Luo, Yawen; Ly, Philip T T; Cai, Fang; Zhou, Weihui; Zou, Haiyan; Song, Weihong

    2012-06-01

    Huntington's disease (HD) is a hereditary neurodegenerative disorder resulting from the expansion of a polyglutamine tract in the huntingtin protein. The expansion of cytosine-adenine-guanine repeats results in neuronal loss in the striatum and cortex. Mutant huntingtin (HTT) may cause toxicity via a range of different mechanisms. Recent studies indicate that impairment of wild-type HTT function may also contribute to HD pathogenesis. However, the mechanisms regulating HTT expression have not been well defined. In this study, we cloned 1,795 bp of the 5' flanking region of the human huntingtin gene (htt) and identified a 106-bp fragment containing the transcription start site as the minimal region necessary for promoter activity. Sequence analysis reveals several putative regulatory elements including Sp1, NF-κB, HIF, CREB, NRSF, P53, YY1, AP1, and STAT in the huntingtin promoter. We found functional Sp1 response elements in the huntingtin promoter region. The expression of Sp1 enhanced huntingtin gene transcription and the inhibition of Sp1-mediated transcriptional activation reduced huntingtin gene expression. These results suggest that Sp1 plays an important role in the regulation of the human huntingtin gene expression at the mRNA and protein levels. Our study suggests that the dysregulation of Sp1-mediated huntingtin transcription, combining with mutant huntingtin's detrimental effect on other Sp1-mediated downstream gene function, may contribute to the pathogenesis of HD. PMID:22399227

  9. Resistance-nodulation-cell division-type efflux pump involved in aminoglycoside resistance in Acinetobacter baumannii strain BM4454.

    Magnet, S; Courvalin, P; Lambert, T

    2001-12-01

    Multidrug-resistant strain Acinetobacter baumannii BM4454 was isolated from a patient with a urinary tract infection. The adeB gene, which encodes a resistance-nodulation-cell division (RND) protein, was detected in this strain by PCR with two degenerate oligodeoxynucleotides. Insertional inactivation of adeB in BM4454, which generated BM4454-1, showed that the corresponding protein was responsible for aminoglycoside resistance and was involved in the level of susceptibility to other drugs including fluoroquinolones, tetracyclines, chloramphenicol, erythromycin, trimethoprim, and ethidium bromide. Study of ethidium bromide accumulation in BM4454 and BM4454-1, in the presence or in the absence of carbonyl cyanide m-chlorophenylhydrazone, demonstrated that AdeB was responsible for the decrease in intracellular ethidium bromide levels in a proton motive force-dependent manner. The adeB gene was part of a cluster that included adeA and adeC which encodes proteins homologous to membrane fusion and outer membrane proteins of RND-type three-component efflux systems, respectively. The products of two upstream open reading frames encoding a putative two-component regulatory system might be involved in the regulation of expression of the adeABC gene cluster. PMID:11709311

  10. Novel cassette array in a class 1 integron in clinical isolates of Acinetobacter baumannii from central Iran.

    Japoni-Nejad, Alireza; Farshad, Shohreh; van Belkum, Alex; Ghaznavi-Rad, Ehsanollah

    2013-12-01

    Antibiotic resistance in Acinetobacter baumannii is a major problem in the hospital and outbreaks caused by this organism have been reported frequently. The present study aimed at determining the antibiotic susceptibility patterns, the prevalence of different classes of integrons and the characterization of integron class 1 gene cassettes in Iranian A. baumannii isolates. A total of 63 non-duplicate A. baumannii isolates were collected from clinical and environmental specimens in the Vali-Asr hospital in the central province of Iran (March to September, 2011). The antimicrobial susceptibility for 15 antibiotics which are used conventionally was determined by disk diffusion. The presence of different integron classes was investigated by PCR and the size of gene cassettes in class 1 integrons was then determined by PCR as well. Moreover, integron cassette arrays of isolates were delineated by RFLP and sequencing amplicons with different lengths. Of 63 isolates 62 (98.4%) carried a class 1 integron. The prevalence of IntI2 was 15.9% and the length of the amplicons ranged from 500 bp to 3 kb. Sequencing of integrons of class 1 revealed the presence of many resistance genes (aadA, aacA, aacC, dfrA, bla(GES) and bla(IMP)). We identified a completely new gene cassette which contained aacA7-qacF-aadA5-bla(IMP), this cassette has not been reported previously in A. baumannii. PMID:24161711

  11. Antimicrobial action of zinc oxide nanoparticles in combination with ciprofloxacin and ceftazidime against multidrug-resistant Acinetobacter baumannii.

    Ghasemi, F; Jalal, R

    2016-09-01

    Acinetobacter baumannii is a serious concern amongst hospitalised patients worldwide and its resistance to antibiotics has emerged as a threat to public health in recent years. Metal oxide nanoparticles were found to be effective for overcoming bacterial resistance owing to their antibacterial activities. The aim of this study was to investigate the combined effects of zinc oxide nanoparticles (ZnO-NPs) and the conventional antibiotics ciprofloxacin and ceftazidime as well as their mechanisms of action against resistant A. baumannii. ZnO-NPs were prepared by the solvothermal method and were characterised by various methods. Broth microdilution and disk diffusion methods were used to determine the antibacterial activities of ciprofloxacin and ceftazidime antibiotics in the absence and presence of a subinhibitory concentration of ZnO-NPs. The mechanism of action of ZnO-NPs alone and in combination with these antibiotics was assessed by flow cytometry, DNA extraction, fluorescence and scanning electron microscopy. The results showed that the antibacterial activities of both antibiotics increased in the presence of a subinhibitory concentration of ZnO-NPs. Combination of ZnO-NPs with antibiotics increased the uptake of antibiotics and changed the bacterial cells from rod to cocci forms. Bacterial filamentation was also observed and exhibited no DNA fragmentation. In conclusion, the results of this study indicate that ZnO-NPs potentiate the antimicrobial action of ciprofloxacin and ceftazidime. A mechanism is proposed to explain this phenomenon. PMID:27530853

  12. Antibacterial Effects of Origanum vulgare Essence Against Multidrug-Resistant Acinetobacter baumannii Isolated From Selected Hospitals of Tehran, Iran

    Saghi

    2015-02-01

    Full Text Available Background Infection due to Acinetobacter baumannii has become a significant challenge to modern healthcare systems. The rapid emergence and global dissemination of A. baumannii as a major nosocomial pathogen is remarkable and it demonstrates its successful adaptation to the 21st century hospital environment. Recent studies have discussed about essential oil of Origanum vulgare against a range of bacteria, including various species of Staphylococcus, Pseudomonas, Bacillus and Escherichia coli. Objectives The present study aimed to investigate the inhibitory effects O. vulgare essence against multidrug-resistant (MDR strains of A. baumannii from selected hospitals in Tehran, Iran. Materials and Methods This oil was obtained using the hydrodistillation method and analyzed by gas chromatography mass spectrography (GC/MS. The antimicrobial activity against MDR isolates was achieved using disc diffusion method and macro-broth dilution assay. Results Analysis of the essential oil revealed the presence of pulegone (68.59% piperitone (7.8%, piperitenone (7.8%, 1, 8-cineole (1.3%, and carvacrol (1.6% as the major components. The results showed a significant activity against MDR A. baumannii with inhibition zones and minimal inhibitory concentration values in the ranges of 7-15 mm and 20-35 µL/mL respectively. Conclusions This investigation showed that the essence oil of O. vulgare had a potent antimicrobial activity against MDR A. baumannii. Further research is required to evaluate the practical values of therapeutic applications.

  13. Antibiotic resistance and OXA-type carbapenemases-encoding genes in airborne Acinetobacter baumannii isolated from burn wards.

    Gao, Jing; Zhao, Xiaonan; Bao, Ying; Ma, Ruihua; Zhou, Yufa; Li, Xinxian; Chai, Tongjie; Cai, Yumei

    2014-03-01

    The study was conducted to investigate drug resistance, OXA-type carbapenemases-encoding genes and genetic diversity in airborne Acinetobacter baumannii (A. baumannii) in burn wards. Airborne A. baumannii were collected in burn wards and their corridors using Andersen 6-stage air sampler from January to June 2011. The isolates susceptibility to 13 commonly used antibiotics was examined according to the CLSI guidelines; OXA-type carbapenemases-encoding genes and molecular diversity of isolates were analyzed, respectively. A total of 16 non-repetitive A. baumannii were isolated, with 10 strains having a resistance rate of greater than 50% against the 13 antibiotics. The resistance rate against ceftriaxone, cyclophosvnamide, ciprofloxacin, and imipenem was 93.75% (15/16), but no isolate observed to be resistant to cefoperazone/sulbactam. Resistance gene analyses showed that all 16 isolates carried OXA-51, and 15 isolates carried OXA-23 except No.15; but OXA-24 and OXA-58 resistance genes not detected. The isolates were classified into 13 genotypes (A-M) according to repetitive extragenic palindromic sequence PCR (REP-PCR) results and only six isolates had a homology ≥90%. In conclusion, airborne A. baumannii in the burn wards had multidrug resistance and complex molecular diversity, and OXA-23 and OXA-51 were dominant mechanisms for resisting carbapenems. PMID:23886986

  14. Preliminary evaluation of adherence on abiotic and cellular surfaces of Acinetobacter baumannii strains isolated from catheter tips

    Gislaine Franco de Moura Costa

    2006-10-01

    Full Text Available The cell surface hydrophobicity and adhesion to abiotic and cellular surfaces was tested in five clinical strains of Acinetobacter baumannii isolated from catheter tips. Biochemical and molecular characteristics of these strains were also studied. Hydrophobicity was characterized by a test for affinity to xylene. Adhesion to abiotic surfaces (polystyrene, formica, latex and glass was evaluated in Petri plates using the stamp technique. Buccal epithelial cells were used for tests of adhesion to cellular surfaces. Adhesion to the catheter was evaluated by repeatedly rinsing the catheters and rolling them over nutrient agar. Molecular typing of the strains was done by the ERIC-PCR technique. The degree of hydrophobicity of the strains varied from hydrophobic to hydrophilic. All the strains adhered to the cell surfaces and to the catheters, and three of them strongly adhered to latex, polystyrene and formica. Catheter adhesion was reduced by meropenem. We found a direct relationship between the degree of bacterial hydrophobicity and adhesion to the abiotic surfaces, but not with adhesion to cellular surfaces, which suggests that different mechanisms are involved in adherence.

  15. An outbreak of Acinetobacter baumannii septicemia in a neonatal intensive care unit of a university hospital in Brazil

    Denise von Dolinger de Brito

    2005-08-01

    Full Text Available We studied an outbreak of two multi-drug resistant clones of Acinetobacter baumannii in the Neonatal Intensive Care Unit of the Uberlândia Federal University Hospital in Minas Gerais state, Brazil, and we analyzed the contribution of cross-transmission in the rise in infection rates. Eleven neonates who developed multi-drug resistant A. baumannii nosocomial infection were matched to 22 neonates who were admitted to the same unit and did not develop an infection during the outbreak period, in order to identify risk factors for infection. Three out of the 11 neonates died. Epidemiological investigation included molecular typing, using pulsed field gel electrophoresis. Prior to the outbreak, from December 2001 to March 2002, no case of infection by this microorganism was diagnosed. Environmental and healthcare worker hand cultures were negative. Nine isolates had similar pulsed field gel electrophoresis patterns and two had another clone. The first clone was brought into the unit by an infected patient who was transferred from another hospital without a history of antibiotic use. The second clone did have its origin clearly defined. Both infected groups led us to conclude that several factors contributed to infection with A. baumannii. These factors were: exposure to antibiotics and invasive devices, birth weight 7 days. Based on logistic regression, infected neonates were more exposed to carbapenem and mechanical ventilation than the control group. Cross transmission between infants contributed to the rise in the rates of multi-drug resistant A. baumannii infection.

  16. Multidrug Resistance Related to Biofilm Formation in Acinetobacter baumannii and Klebsiella pneumoniae Clinical Strains from Different Pulsotypes.

    de Campos, Paola Amaral; Royer, Sabrina; da Fonseca Batistão, Deivid William; Araújo, Bruna Fuga; Queiroz, Lícia Ludendorff; de Brito, Cristiane Silveira; Gontijo-Filho, Paulo P; Ribas, Rosineide Marques

    2016-05-01

    The emergence of Acinetobacter baumannii and Klebsiella pneumoniae strains in the hospital environment has been associated with the presence of multiple genetic elements, virulence factors and the ability to form biofilms. This study evaluated the biofilm formation ability of clinical and environmental A. baumannii and K. pneumoniae strains, isolated from various sources and presenting different molecular characteristics, resistance profiles and pulsed-field gel electrophoresis patterns. Fifty-three isolates were recovered from 2009 to 2014 in a Brazilian university hospital. Investigation of biofilm formation was performed for 10 strains of each species assessed by an initial adhesion assay, biofilm cell concentration and biofilm biomass, evaluated by quantitative assays in replicates, in three independent experiments. All strains of A. baumannii were able to attach to polystyrene plates, although two strains adhered to a lesser degree than the control. K. pneumoniae strains showed opposite behaviour, where only three strains adhered significantly when compared to the control. Quantitative evaluation revealed that in five A. baumannii and four K. pneumoniae isolates the biomass production could be characterised as moderate. None of the isolates were strong biofilm producers. Our results demonstrate: (1) biofilm formation is a heterogeneous property amongst A. baumannii and K. pneumoniae clinical strains and it was not associated with certain clonal types; (2) no relationship between multidrug resistance and biofilm production was observed; (3) more virulent K. pneumoniae strains tended to present higher production of biofilm. PMID:26846651

  17. [Effect of Cu2+ on synthesis of biosurfactants of Acinetobacter calcoaceticus IMV B-7241 and Rhodococcus erythropolis IMV Ac-5017].

    Pirog, T P; Konon, A D; Sofilkanich, A P; Shevchuk, T A; Parfeniuk, S A

    2013-01-01

    Synthesis of biosurfactants (surface-active substances, SAS) was investigated under the conditions of growth of Rhodococcus erythropolis IMV Ac-5017 and Acinetobacter calcoaceticus IMV B-7241 on hydrophobic (n-hexadecane, liquid paraffins, sunflower oil) and hydrophilic (ethanol) substrates depending on concentration (0.01-0.5 mM) and time of copper cations introduction in the medium. It is established that Cu2+ addition in the exponential phase of growth of the strains IMV B-7241 and IMV Ac-5017 on all studied substrates was accompanied by the increase of conventional concentration of SAS by 25-140% as compared with the indices in the medium without copper cations. Maximum synthesis intensification of SAS of A. calcoaceticus IMV B-7241 and R. erythropolis IMV Ac-5017 was observed in the case of Cu2+ introduction in the medium with hydrocarbons. The increase of SAS synthesis in the presence of copper cations is determined by their activating effect on activity of alkane hydroxylase of the both strains, as well as 4-nitroso-N,N-dimethylaniline-dependent alcohol dehydrogenase and enzymes of biosynthesis of surface active glyco-(phosphoenolpyruvate-synthetase) and aminolipids (NADP(+)-dependent glutamate dehydrogenase) in A. calcoaceticus IMV B-7241. PMID:23516834

  18. Low-Frequency Ultrasound Enhances Antimicrobial Activity of Colistin-Vancomycin Combination against Pan-Resistant Biofilm of Acinetobacter baumannii.

    Liu, Xu; Yin, Hong; Weng, Chun-Xiao; Cai, Yun

    2016-08-01

    Acinetobacter baumannii biofilms in catheters are very difficult to treat. Low-frequency ultrasound (LFU) may improve bactericidal or bacteriostatic activity. However, no previous studies have been reported on its efficacy against pan-resistant biofilms of A. baumannii. This study was designed to investigate whether LFU can enhance the activity of colistin, vancomycin and colistin-vancomycin combinations against pan-resistant biofilms of A. baumannii. The efficacy of colistin combinations was determined using the fractional inhibitory concentration index (FICI). The antibacterial effect was determined from bacteria counts in biofilms and the establishment of 24-h time-kill curves. A significantly synergistic effect was detected between colistin and vancomycin (FICI colistin in the combination treatments resulted in a better ultrasound-enhanced antibacterial effect. In 24-h time-kill curves, the combination of colistin (8 μg/mL) plus vancomycin (4 μg/mL) with LFU caused a significant reduction in bacteria counts in biofilms after 8 h and a continuing decline until 24 h. Bacterial counts were reduced by 3.77 log(CFU/mL) by LFU plus combinations, compared with combinations without LFU at 24 h. Our results indicate that LFU in combination with colistin plus vancomycin may be useful in treating pan-resistant A. baumannii infections. PMID:27131840

  19. The molecular epidemiological study of colistin-only-sensitive strains in multi-drug resistant Acinetobacter baumannii

    YANG Li; HAN Lizhong; SUN Jingyong; YU Yunsong; NI Yuxing

    2007-01-01

    This paper reported the epidemiology of the colistin-only-sensitive Acinetobacter baumannii(COS-AB)in a tertiary teaching hospital in China.We analyzed the clinical data of 136 COS-AB isolates from June 2004 to May 2005 and collected 66 A.baumannii isolates in which 33 strains were COS-AB,and the rest were non-COS-AB.Random amplified polymorphic DNA(RAPD)analysis (primer ERIC2 and 272)showed that all COS-AB were identical,while pulsed-field gel electrophotesis(PFGE)analysis showed two separate genotypes of these COS-ABwhich were distinctly different from that of non-COS-AB.The COS-AB from burn wards showed the identical PFGE pattern which was distinguished from the genotype of COS-AB in other departments,mainly surgical systems.The cross-infection was severe and strict methods of disinfection and sterilization should be implemented.Meanwhile,the epidemiology of COS-AB in environment and patients should be closely monitored.The PFGE analysis is a reliable method of A.baumannii typing.

  20. Epidemiology and clonality of carbapenem-resistant Acinetobacter baumannii from an intensive care unit in Palermo, Italy

    Mammina Caterina

    2012-07-01

    Full Text Available Abstract Background Multidrug-resistant Acinetobacter baumannii, initially considered as having a poor clinical relevance, is frequently isolated from infection cases in intensive care units. We describe the epidemiology of carbapenem resistant A. baumannii (CRAB in a general ICU in Palermo, Italy, from October 2010 to March 2011. Findings 58 of 61 isolates exhibited MICs for meropenem or imipenem ≥16 mg/L. Forty-nine carried blaOXA-23 and two blaOXA-58 genes. Five subtype clusters were detected by rep-PCR. Clusters D and E included 10 isolates that tested negative for the carbapenem resistance genes. MLST attributed all isolates, but two, with sequence type (ST2, whereas the two remaining isolates with ST78. The respiratory tract was the most common site of infection (26 out of 36 cases. 72.2%. A high infection related mortality rate was observed (18 out of 35 patients, 51.4%. Nineteen patients tested positive for other multidrug resistant organisms in addition to CRAB. In eight cases isolates belonging to distinct subtype clusters and/or with distinct carbapenemase profiles were identified. Conclusions Carbapenem resistance was prominently driven by the dissemination of CRAB isolates belonging to ST2, carrying the carbapenemase gene blaOXA-23. The colonization/infection of some patients by multiple strains is suggestive of an endemic circulation of CRAB.

  1. Microcalorimetric investigation of the toxic action of pyrene on the growth of PAH-degrading bacteria Acinetobacter junii.

    Chen, Yanjiao; Yao, Jun; Chen, Ke; Wang, Fei; Zhou, Yong; Chen, Huilun; Gai, Nan; Ceccanti, Brunello; Trebse, Polonca; Zaray, Gyula; Choi, Martin M F; Wong, Ming Hong

    2010-01-01

    A multi-channel thermal activity microcalorimeter was used to determine the pyrene-induced toxic effect on two polycyclic aromatic hydrocarbon (PAH)-degrading bacteria Acinetobacter junii (A. junii) and Bacillus subtilis (B. subtilis). Power-time curves were analyzed and calorimetric parameters including growth rate constant (k), half inhibitory concentration (IC50) and total thermal effect (QT) were obtained. A. junii and B. subtilis were completely inhibited when the concentration of pyrene reached 400 and 160 microg mL(-1), respectively. The relationships between the calorimetric parameters and concentration of pyrene were studied. The growth rate of A. junii decreased with the increase in pyrene concentration at 50-200 microg mL(-1). The growth of biomass for A. junii at various concentrations of pyrene was determined. The count of A. junii after 8 day's incubation reached maximum irrespective of the initial pyrene concentrations ranging from 50 to 200 microg mL(-1) and the smallest stimulative action of pyrene was at 200 microg mL(-1). The variations of biomass during the growth of A. junii were consistent with the microcalorimetric data, indicating that microcalorimetry can be an effective technique to investigate the effect of pyrene on microorganisms. PMID:20390914

  2. Imported PER-1 producing Pseudomonas aeruginosa, PER-1 producing Acinetobacter baumanii and VIM-2-producing Pseudomonas aeruginosa strains in Hungary

    Nagy Károly

    2008-05-01

    Full Text Available Abstract Introduction Pseudomonas aeruginosa and Acinetobacter baumanii are important nosocomial pathogens with wide intrinsic resistance. However, due to the dissemination of the acquired resistance mechanisms, such as extended-spectrum beta-lactamase (ESBL and metallo beta-lactamase (MBL production, multidrug resistant strains have been isolated more often. Case presentation We report a case of a Hungarian tourist, who was initially hospitalized in Egypt and later transferred to Hungary. On the day of admission PER-1-producing P. aeruginosa, PER-1 producing A. baumannii, SHV-5-producing Klebsiella pneumoniae and VIM-2-producing P. aeruginosa isolates were subcultured from the patient's samples in Hungary. Comparing the pulsed-field gel electrophoresis (PFGE patterns of the P. aeruginosa strains from the patient to the P. aeruginosa strains occurring in this hospital, we can state that the PER-1-producing P. aeruginosa and VIM-2-producing P. aeruginosa had external origin. Conclusion This is the first report of PER-1-producing P. aeruginosa,and PER-1-producing A. baumanii strains in Hungary. This case highlights the importance of spreading of the beta-lactamase-mediated resistance mechanisms between countries and continents, showing the importance of careful screening and the isolation of patients arriving from a different country.

  3. Inhibitory effects of reserpine and carbonyl cyanide m-chloro-phenylhydrazone on fluoroquinolone resistance of Acinetobacter baumannii

    SHI Wei-feng; JIANG Jian-ping; XU Ning; HUANG Zhi-mi; WANG Yu-yue

    2005-01-01

    @@ Mechanisms of bacterial resistance to fluoro-quinolones may be grouped into three principal categories: gene mutations of DNA topoisomerase Ⅱ (GyrA or GyrB), DNA topoisomerase Ⅳ (ParC or ParE), decrease of outer membrane permeation and upregulation of multi-drug efflux pump (active efflux system).1 Efflux pumps are transport proteins removing toxic substrates (including virtually all classes of clinically relevant antibiotics) from cells to the external environment. These proteins exist in both Gram positive bacteria and Gram negative bacteria as well as in fungi and mammalian (tumour) cells.2-4 It has been reported that alkaloid reserpine and carbonyl cyanide m-chlorophenylhydrazone (CCCP) can inhibit NorA multi-drug efflux.5,6 In order to explore the universality of drug efflux in microorganisms, 85 strains of Acinetobacter baumannii (A. Baumannii) were tested using reserpine and CCCP. The quinolone-resistant-determining region (QRDR) of gyrA and parC genes in 35 isolates of A. Baumannii were amplified by polymerase chain reaction (PCR) and sequenced by DNA sequencer. The correlation between resistant mutation regularity and bacterial drug efflux were analysed.

  4. Colistin and Fusidic Acid, a Novel Potent Synergistic Combination for Treatment of Multidrug-Resistant Acinetobacter baumannii Infections.

    Phee, Lynette M; Betts, Jonathan W; Bharathan, Binutha; Wareham, David W

    2015-08-01

    The spread of multidrug-resistant Acinetobacter baumannii (MDRAB) has led to the renaissance of colistin (COL), often the only agent to which MDRAB remains susceptible. Effective therapy with COL is beset with problems due to unpredictable pharmacokinetics, toxicity, and the rapid selection of resistance. Here, we describe a potent synergistic interaction when COL was combined with fusidic acid (FD) against A. baumannii. Synergy in vitro was assessed against 11 MDRAB isolates using disc diffusion, checkerboard methodology (fractional inhibitory concentration index [FICI] of ≤ 0.5, susceptibility breakpoint index [SBPI] of >2), and time-kill methodology (≥2 log10 CFU/ml reduction). The ability of FD to limit the emergence of COL resistance was assessed in the presence and absence of each drug alone and in combination. Synergy was demonstrated against all strains, with an average FICI and SBPI of 0.064 and 78.85, respectively. In time-kill assays, COL-FD was synergistic and rapidly bactericidal, including against COL-resistant strains. Fusidic acid prevented the emergence of COL resistance, which was readily selected with COL alone. This is the first description of a novel COL-FD regimen for the treatment of MDRAB. The combination was effective at low concentrations, which should be therapeutically achievable while limiting toxicity. Further studies are warranted to determine the mechanism underlying the interaction and the suitability of COL-FD as an unorthodox therapy for the treatment of multidrug-resistant Gram-negative infections. PMID:25987639

  5. Diversity and Evolution of AbaR Genomic Resistance Islands in Acinetobacter baumannii Strains of European Clone I▿†

    Krizova, Lenka; Dijkshoorn, Lenie; Nemec, Alexandr

    2011-01-01

    To assess the diversity of AbaR genomic resistance islands in Acinetobacter baumannii European clone I (MLST clonal complex 1), we investigated 26 multidrug-resistant strains of this major clone isolated from hospitals in 21 cities of 10 European countries between 1984 and 2005. Each strain harbored an AbaR structure integrated at the same position in the chromosomal ATPase gene. AbaR3, including four subtypes based on variations in class 1 integron cassettes, and AbaR10 were found in 15 and 2 strains, respectively, whereas a new, unique AbaR variant was discovered in each of the other 9 strains. These new variants, designated AbaR11 to AbaR19 (19.8 kb to 57.5 kb), seem to be truncated derivatives of AbaR3, likely resulting from the deletions of its internal parts mediated by either IS26 elements (AbaR12 to AbaR19) or homologous recombination (AbaR11). AbaR3 was detected in all 10 strains isolated in 1984 to 1991, while AbaR11 to AbaR19 were carried only by strains isolated since 1997. Our results and those from previous publications suggest that AbaR3 is the original form of AbaR in European clone I, which may have provided strains of the lineage with a selective advantage facilitating their spread in European hospitals in the 1980s or before. PMID:21537009

  6. Molecular Epidemiology of Carbapenem-Resistant Acinetobacter Baumannii Complex Isolates from Patients that were Injured During the Eastern Ukrainian Conflict.

    Granzer, Heike; Hagen, Ralf Matthias; Warnke, Philipp; Bock, Wolfgang; Baumann, Tobias; Schwarz, Norbert Georg; Podbielski, Andreas; Frickmann, Hagen; Koeller, Thomas

    2016-06-24

    This study addressed carbapenem-resistant Acinetobacter baumannii complex (ABC) isolates from patients that were injured during the military conflict in the Eastern Ukraine and treated at German Armed Forces Hospitals in 2014 and 2015. Clonal diversity of the strains and potential ways of transmission were analyzed. Patients with one or several isolation events of carbapenem-resistant ABC were included. Isolates were characterized by VITEK II-based identification and resistance testing, molecular screening for frequent carbapenemase genes, and DiversiLab rep-PCR-based typing. Available clinical information of the patients was assessed. From 21 young male Ukrainian patients with battle injuries, 32 carbapenem- and fluoroquinolone-resistant ABC strains were isolated. Four major clonal clusters were detected. From four patients (19%), ABC isolates from more than one clonal cluster were isolated. The composition of the clusters suggested transmission events prior to the admission to the German hospitals. The infection and colonization pressure in the conflict regions of the Eastern Ukraine with ABC of low clonal diversity is considerable. Respective infection risks have to be considered in case of battle-related injuries in these regions. The low number of local clones makes any molecular exclusion of transmission events difficult. PMID:27429793

  7. NDM-1-producing Acinetobacter baumannii ST85 now in Turkey, including one isolate from a Syrian refugee.

    Heydari, Farzad; Mammina, Caterina; Koksal, Fatih

    2015-09-01

    New Delhi metallo-β-lactamase-1 (NDM-1), an acquired class B carbapenemase, is a significant clinical threat owing to the extended hydrolysis of β-lactams including carbapenems. Here, to the best of our knowledge we describe for the first time in Turkey two NDM-1-producing Acinetobacter baumannii isolates recovered from intensive care unit patients. The presence of blaNDM-1 was detected by PCR and confirmed by sequencing. The clonal relationship was assessed by PFGE and multilocus sequence typing. Both isolates were positive for blaNDM-1 and were attributed with the sequence type 85. One isolate was from a Syrian refugee, whereas the second was from a patient who had never travelled outside Turkey. Our findings confirmed that the rapid spread of NDM-1-producing Gram-negative organisms could become a major challenge for the treatment and control of healthcare-associated infections in our geographical area. They suggest also that NDM-1-producing strains and/or their genetic determinants are probably being imported from Syria to neighbouring countries. PMID:26296677

  8. Early detection of metallo-β-lactamase NDM-1- and OXA-23 carbapenemase-producing Acinetobacter baumannii in Libyan hospitals.

    Mathlouthi, Najla; El Salabi, Allaaeddin Ali; Ben Jomàa-Jemili, Mariem; Bakour, Sofiane; Al-Bayssari, Charbel; Zorgani, Abdulaziz A; Kraiema, Abdulmajeed; Elahmer, Omar; Okdah, Liliane; Rolain, Jean-Marc; Chouchani, Chedly

    2016-07-01

    Acinetobacter baumannii is an opportunistic pathogen causing various nosocomial infections. The aim of this study was to characterise the molecular support of carbapenem-resistant A. baumannii clinical isolates recovered from two Libyan hospitals. Bacterial isolates were identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Antibiotic susceptibility testing was performed using disk diffusion and Etest methods, and carbapenem resistance determinants were studied by PCR amplification and sequencing. Multilocus sequence typing (MLST) was performed for typing of the isolates. All 36 imipenem-resistant isolates tested were identified as A. baumannii. The blaOXA-23 gene was detected in 29 strains (80.6%). The metallo-β-lactamase blaNDM-1 gene was detected in eight isolates (22.2%), showing dissemination of multidrug-resistant (MDR) A. baumannii in Tripoli Medical Center and Burn and Plastic Surgery Hospital in Libya, including one isolate that co-expressed the blaOXA-23 gene. MLST revealed several sequence types (STs). Imipenem-resistant A. baumannii ST2 was the predominant clone (16/36; 44.4%). This study shows that NDM-1 and OXA-23 contribute to antibiotic resistance in Libyan hospitals and represents the first incidence of the association of these two carbapenemases in an autochthonous MDR A. baumannii isolated from patients in Libya, indicating that there is a longstanding infection control problem in these hospitals. PMID:27216382

  9. Simultaneous enhancement of phenolic compound degradations by Acinetobacter strain V2 via a step-wise continuous acclimation process.

    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. PMID:26471472

  10. Zingiber officinale (ginger) compounds have tetracycline-resistance modifying effects against clinical extensively drug-resistant Acinetobacter baumannii.

    Wang, Hui-Min; Chen, Chung-Yi; Chen, Hsi-An; Huang, Wan-Chun; Lin, Wei-Ru; Chen, Tun-Chieh; Lin, Chun-Yu; Chien, Hsin-Ju; Lu, Po-Liang; Lin, Chiu-Mei; Chen, Yen-Hsu

    2010-12-01

    Extensively drug-resistant Acinetobacter baumannii (XDRAB) is a growing and serious nosocomial infection worldwide, such that developing new agents against it is critical. The antimicrobial activities of the rhizomes from Zingiber officinale, known as ginger, have not been proven in clinical bacterial isolates with extensive drug-resistance. This study aimed to investigate the effects of four known components of ginger, [6]-dehydrogingerdione, [10]-gingerol, [6]-shogaol and [6]-gingerol, against clinical XDRAB. All these compounds showed antibacterial effects against XDRAB. Combined with tetracycline, they showed good resistance modifying effects to modulate tetracycline resistance. Using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, these four ginger compounds demonstrated antioxidant properties, which were inhibited by MnO₂, an oxidant without antibacterial effects. After the antioxidant property was blocked, their antimicrobial effects were abolished significantly. These results indicate that ginger compounds have antioxidant effects that partially contribute to their antimicrobial activity and are candidates for use in the treatment of infections with XDRAB. PMID:20564496

  11. Colistin and Fusidic Acid, a Novel Potent Synergistic Combination for Treatment of Multidrug-Resistant Acinetobacter baumannii Infections

    Betts, Jonathan W.; Bharathan, Binutha

    2015-01-01

    The spread of multidrug-resistant Acinetobacter baumannii (MDRAB) has led to the renaissance of colistin (COL), often the only agent to which MDRAB remains susceptible. Effective therapy with COL is beset with problems due to unpredictable pharmacokinetics, toxicity, and the rapid selection of resistance. Here, we describe a potent synergistic interaction when COL was combined with fusidic acid (FD) against A. baumannii. Synergy in vitro was assessed against 11 MDRAB isolates using disc diffusion, checkerboard methodology (fractional inhibitory concentration index [FICI] of ≤ 0.5, susceptibility breakpoint index [SBPI] of >2), and time-kill methodology (≥2 log10 CFU/ml reduction). The ability of FD to limit the emergence of COL resistance was assessed in the presence and absence of each drug alone and in combination. Synergy was demonstrated against all strains, with an average FICI and SBPI of 0.064 and 78.85, respectively. In time-kill assays, COL-FD was synergistic and rapidly bactericidal, including against COL-resistant strains. Fusidic acid prevented the emergence of COL resistance, which was readily selected with COL alone. This is the first description of a novel COL-FD regimen for the treatment of MDRAB. The combination was effective at low concentrations, which should be therapeutically achievable while limiting toxicity. Further studies are warranted to determine the mechanism underlying the interaction and the suitability of COL-FD as an unorthodox therapy for the treatment of multidrug-resistant Gram-negative infections. PMID:25987639

  12. Safradan İzole Edilen Campylobacter Sp.

    Yorgancıgil, Birdal; Tezeren, Deniz; Balaban, Neriman; Terzioğlu, Serdar; Öztürk, Süheyla

    2009-01-01

    SüleymanDemirel Üniversitesi TIP FAKÜLTESİ DERGİSİ: 1997 Haziran; 4(3) Safradan İzole Edilen Campylobacter Sp. Birdal YORGANCIGİL Deniz TEZEREN Neriman BALABAN Serdar TERZlOĞLU Süheyla ÖZTÜRK Özet Campylobacter sp. 'in neden olduğu, gastrointestinal traktüs haricindeki lokal veya sistemik infeksiyon vakaları oldukça azdır. Bu çalışmada safradan izole edilen bir Campylobacter sp. olgusu incelenmiştir. Ankara Numune Hastanesi Cerrahi Kliniğinde koles...

  13. Coexistence of Extended Spectrum Beta-Lactamases, AmpC Beta-Lactamases and Metallo-Beta-Lactamases in Acinetobacter baumannii from burns patients: a report from a tertiary care centre of India.

    Gupta, V; Garg, R; Garg, S; Chander, J; Attri, A K

    2013-12-31

    Multidrug-resistant Acinetobacter baumanii is a major pathogen encountered in pyogenic infections, especially from burns patients in hospital settings. Often there is also coexistence of multiple beta-lactamase enzymes responsible for beta-lactam resistance in a single isolate, which further complicates treatment options. We conducted a study on burn wound pus samples obtained from the burns unit of our hospital. Phenotypic tests were used to determine the Extended Spectrum Beta-Lactamase, AmpC Beta-Lactamase and Metallo-Beta-Lactamase producing status of the isolates. Almost half of the samples from the burn wounds yielded Acinetobacter baumanii as the predominant pathogen (54.05%). Coexistence of the three resistance mechanisms was seen in 25 of the 100 (25%) isolates of Acinetobacter baumanii. This study emphasizes the need for the detection of isolates that produce these enzymes to avoid therapeutic failures and nosocomial outbreaks. PMID:24799848

  14. Uji Efektifitas Jamur Antagonis Trichoderma sp. Dan Gliocladium sp. Untuk Mengendalikan Penyakit Layu Fusarium

    Nasution, Rima Yunisa

    2015-01-01

    Rima Yunisa Nasution. 2014. Effectiveness test on antagonist fungi Trichoderma sp. and Gliocladium Sp. to control fusarium disease (Fusarium oxysporum F.sp capsici) for chilli crop (Capsicum Annuum L.) at screen house. Supervised by Lahmuddin Lubis and Hassanuddin. The goal of the research is to examine antagonist fungi Trichoderma and Gliocladium virens towards F. Oxysporum that lead the fusarium disease for chilli crop at screen house. The research was conducted at Plant Dise...

  15. Tubulinosema sp. Microsporidian Myositis in Immunosuppressed Patient

    Choudhary, Maria M.; Metcalfe, Maureen G.; Arrambide, Kathryn; Bern, Caryn; Visvesvara, Govinda S.; Pieniazek, Norman J.; Bandea, Rebecca D.; Deleon-Carnes, Marlene; Adem, Patricia; Choudhary, Moaz M.; Zaki, Sherif R.; Saeed, Musab U.

    2011-01-01

    The Phylum Microsporidia comprises >1,200 species, only 15 of which are known to infect humans, including the genera Trachipleistophora, Pleistophora, and Brachiola. We report an infection by Tubulinosema sp. in an immunosuppressed patient.

  16. SP-100 power system development status

    The SP-100 ground engineering system development project objectives, approach and status are described. The SP-100 GES development project is phase II of a three-phase program funded and directed by three United States Federal Agencies (NASA, DOD and DOE) to develop space reactor power systems for space applications in the 10 to 1000 KWe power range. The first phase of the program lasted three years, and this was completed at the end of FY 1985. SP-100 Phase I analytically and experimentally reviewed all near-term space reactor power system candidates and selected one system that best met the project mission requirements for future civilian and military space applications. The SP-100 Phase II started in fiscal year 1986 to develop the Phase I selected space reactor power system to be technically ready for space applications in the mid-to late 1990s. (author)

  17. Silencing the SpMPK1, SpMPK2, and SpMPK3 Genes in Tomato Reduces Abscisic Acid—Mediated Drought Tolerance

    Yan Liang

    2013-11-01

    Full Text Available Drought is a major threat to agriculture production worldwide. Mitogen-activated protein kinases (MAPKs play a pivotal role in sensing and converting stress signals into appropriate responses so that plants can adapt and survive. To examine the function of MAPKs in the drought tolerance of tomato plants, we silenced the SpMPK1, SpMPK2, and SpMPK3 genes in wild-type plants using the virus-induced gene silencing (VIGS method. The results indicate that silencing the individual genes or co-silencing SpMPK1, SpMPK2, and SpMPK3 reduced the drought tolerance of tomato plants by varying degrees. Co-silencing SpMPK1 and SpMPK2 impaired abscisic acid (ABA-induced and hydrogen peroxide (H2O2-induced stomatal closure and enhanced ABA-induced H2O2 production. Similar results were observed when silencing SpMPK3 alone, but not when SpMPK1 and SpMPK2 were individually silenced. These data suggest that the functions of SpMPK1 and SpMPK2 are redundant, and they overlap with that of SpMPK3 in drought stress signaling pathways. In addition, we found that SpMPK3 may regulate H2O2 levels by mediating the expression of CAT1. Hence, SpMPK1, SpMPK2, and SpMPK3 may play crucial roles in enhancing tomato plants’ drought tolerance by influencing stomatal activity and H2O2 production via the ABA-H2O2 pathway.

  18. Presencia de integrones y su relación con la resistencia a cefalosporinas de tercera generación en cepas de Acinetobacter baumannii de origen nosocomial Presence of integrons and their relationships with the resistance to third generation cephalosporins among nosocomial isolates of Acinetobacter baumannii

    César Ramírez G; Carolina Pino I; Gerardo González R; Helia Bello T; Mariana Domínguez Y; Sergio Mella M; Raúl Zemelman Z; Young, Hilary K.; Sebastian GB Amyes

    2000-01-01

    Background: Acinetobacter baumannii is an important etiological agent causing nosocomial infections. High level of resistance for different kind of antimicrobials has been observed, including ß-lactam antibiotics. This feature, chromosomal or plasmid encoded, has been associated to integrons harbouring antibiotic resistance gene cassettes. Aims: To investigate the presence of integrons among clinical isolates resistant to third generation cephalosporins (3GC). Material and methods: One hundre...

  19. Heptaketides with antiviral activity from three endolichenic fungal strains Nigrospora sp., Alternaria sp. and Phialophora sp.

    He, Jun-Wei; Chen, Guo-Dong; Gao, Hao; Yang, Fan; Li, Xiao-Xia; Peng, Tao; Guo, Liang-Dong; Yao, Xin-Sheng

    2012-09-01

    Two new heptaketides, (+)-(2S,3S,4aS)-altenuene (1a) and (-)-(2S,3S,4aR)-isoaltenuene (2a), together with six known compounds, (-)-(2R,3R,4aR)-altenuene (1b), (+)-(2R,3R,4aS)-isoaltenuene (2b), 5'-methoxy-6-methyl-biphenyl-3,4,3'-triol (3), alternariol (4), alternariol-9-methyl ether (5), and 4-hydroxyalternariol-9-methyl ether (6) were isolated from the EtOAc extract of an endolichenic fungal strain Nigrospora sphaerica (No.83-1-1-2). Compounds 1a and 1b were separated from enantiomers 1 by chiral HPLC, and so were 2a and 2b from enantiomers 2. Interestingly, 1-6 were also obtained from other two endolichenic fungal strains Alternaria alternata (No.58-8-4-1) and Phialophora sp. (No.96-1-8-1). The structures of 1-6 were elucidated by means of MS, HR-MS, NMR, and X-ray diffraction. Furthermore, the absolute configurations of 1a-2b were determined by CD experiments and CD calculation. Of these compounds, 4 and 5 showed antiviral activity against herpes simplex virus (HSV) in vitro, with IC(50) values of 13.5 and 21.3 μM, and with selective index (SI) values of 26.5 and 17.1, respectively. PMID:22613072

  20. Evaluation of the antibacterial effect of Echium amoenum Fisch. et Mey. against multidrug resistant Acinetobacter baumannii strains isolated from burn wound infection

    Mandana Sabour

    2015-02-01

    Full Text Available Introduction and aims: Acinetobacter baumannii in recent decay has become an increasing concern in hospitals for its ability to acquire antibiotic resistance determinants rapidly and becoming resistant to almost all of the antibiotic classes. Borage (Echium amoenum  Fisch. et Mey, is a wild annual plant of Boraginaceae family, grows in northern mountains of Iran and has largely been used by Iranian folk as a mood enhancer, anti anxiolytic, anti inflammatory, a laxative, an emollients and also it has been used  for treatment of infectious diseases. So, in this study the methanolic extract of dried flowers of Echium amoenom were tested against the isolates of Acinetobacter baumannii from wound of burn patients.Materials and methods: 30 drug resistant Acinetobacter baumannii strains which were isolated from burn wounds at the Motahari hospital of Tehran were selected. Antibacterial activity of the methanolic extract was evaluated by the disc diffusion method based on CLSI protocol 2012Results: The mean diameter of the inhibition zone for different extracts  were; 9.967±6.139 mm at the concentration of 4000 ppm, at the concentration of 400 ppm 13.37±5.45 mm, 13.53±5.49 mm at the concentration of 200 ppm, 14.77±5.17mm  at the concentration of 100 ppm and 14.13±5.7806mm  at the concentration of 50 ppm.Conclusion: clinical strains of the A. baumannii were almost highly resistant to imipenem which is the common choice of antibiotic therapy in the hospitals. Due to the calculated p value ≤ 0.05 in this study, it can say that borage extract can be as good as or even better than the imipenem which is used in the hospitals now.