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Sample records for acinetobacter calcoaceticus phea-2

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

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    Chin-Soon Chee

    2014-01-01

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

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

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

    2014-01-01

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

  3. Nosocomial infections due to Acinetobacter calcoaceticus.

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    Zaer F

    1989-01-01

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

  4. Nosocomial infections due to Acinetobacter calcoaceticus.

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    Zaer, F; Deodhar, L

    1989-01-01

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

  5. Multi-drug-resistant Acinetobacter calcoaceticus-Acinetobacter baumannii complex infection outbreak in dogs and cats in a veterinary hospital.

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    Kuzi, S; Blum, S E; Kahane, N; Adler, A; Hussein, O; Segev, G; Aroch, I

    2016-11-01

    Members of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex cause severe outbreaks in humans, and are increasingly reported in animals. A retrospective study, describing a severe outbreak in dogs and cats caused by a multidrug resistant member of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex in a veterinary hospital, between July 2010 and November 2012. The study included 19 dogs and 4 cats. Acinetobacter calcoaceticus-Acinetobacter baumannii complex bacteria were isolated from urine (9 animals), respiratory tract (11), tissues (3) and blood (1). The most common infection-associated findings included fever, purulent discharge from endotracheal tubes, hypotension, and neutropaenia. Infections led to pneumonia, urinary tract infection, cellulitis and sepsis. Infection was transmitted in the intensive care unit, where 22 of 23 animals were initially hospitalised. The mortality rate was 70% (16 of 23 animals), and was higher in cases of respiratory infection compared to other infections. Aggressive environmental cleaning and disinfection, with staff education for personal hygiene and antisepsis, sharply decreased the infection incidence. Health care-associated outbreaks with multidrug resistant Acinetobacter calcoaceticus-Acinetobacter baumannii complex in dogs and cats are potentially highly fatal and difficult to eradicate, warranting monitoring, antiseptic techniques and judicious antibiotic use. © 2016 British Small Animal Veterinary Association.

  6. Weigle Reactivation in Acinetobacter Calcoaceticus

    DEFF Research Database (Denmark)

    Berenstein, Dvora

    1982-01-01

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

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

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    Zhao, Zhenyong; Wong, Jonathan W C

    2009-03-01

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

  8. Prophage induction by ultraviolet light in Acinetobacter calcoaceticus

    Energy Technology Data Exchange (ETDEWEB)

    Berenstein, D.

    1986-09-01

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

  9. Prophage Induction by Ultraviolet Light in Acinetobacter calcoaceticus

    DEFF Research Database (Denmark)

    Berenstein, D.

    1986-01-01

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

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

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

    2017-05-01

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

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

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    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.

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

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

    1996-05-01

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

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

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    Weimei Ou

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

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

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

    2013-12-01

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

  15. UV-inducible DNA repair in Acinetobacter calcoaceticus

    International Nuclear Information System (INIS)

    Berenstein, D.

    1987-01-01

    Bacterial mutation frequency after UV irradiation and phage mutation frequency under conditions of W-reactivation were determined in A. calcoaceticus. With the exception of streptomycin resistance, there was no increase in the frequency of the assayed markers above the background level. The increased survival of phage during W-reactivation was not followed by an increase in the frequency of mutation from turbid to clear plaque formers among phage survivors. The findings suggested that the UV-inducible repair pathway in A. calcoaceticus was error free. Post-irradiation incubation of UV-treated culture before phage infection resulted in a further increase of W-reactivation. As chloramphenicol inhibited this response, it was concluded that de novo protein synthesis was involved in the UV-inducible repair pathway in A. calcoaceticus. (Auth.)

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

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    Yang Sun

    Full Text Available The presence of multidrug-resistant bacterial pathogens in the environment poses a serious threat to public health. The opportunistic Acinetobacter spp. are among the most prevalent causes of nosocomial infections. Here, we performed complete genome sequencing of the Acinetobacter calcoaceticus strain XM1570, which was originally cultivated from the sputum of a patient diagnosed with pneumonia in Xiamen in 2010. We identified carbapenem resistance associated gene bla(NDM-1 located on a 47.3-kb plasmid. Three methods--natural reproduction, sodium dodecyl sulfate treatment and nalidixic acid treatment--were used to eliminate the bla(NDM-1-encoding plasmid, which achieved elimination rates of 3.32% (10/301, 83.78% (278/332, and 84.17% (298/354, respectively. Plasmid elimination dramatically increased antibiotic sensitivity, reducing the minimum bacteriostatic concentration of meropenem from 256 µg/ml in the clinical strain to 0.125 µg/ml in the plasmid-eliminated strain. Conjugation transfer assays showed that the bla(NDM-1-containing plasmid could be transferred into Escherichia coli DH5α:pBR322 in vitro as well as in vivo in mice. The bla(NDM-1 genetic environment was in accordance with that of other bla(NDM-1 genes identified from India, Japan, and Hong-Kong. The multilocus sequence type of the isolate was identified as ST-70. Two novel genes encoding intrinsic OXA and ADC were identified and named as OXA-417 and ADC-72. The finding of bla(NDM-1 in species like A. calcoaceticus demonstrates the wide spread of this gene in gram-negative bacteria which is possible by conjugative plasmid transfer. The results of this study may help in the development of a treatment strategy for controlling NDM-1 bacterial infection and transmission.

  17. Genotypic and Phenotypic Correlations of Multidrug-Resistant Acinetobacter baumannii-A. calcoaceticus Complex Strains Isolated from Patients at the National Naval Medical Center

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    Acinetobacter baumannii-calcoaceticus complex (ABC) infections have complicated the care of U.S. combat casualties. In this study, 102 ABC isolates from wounded soldiers treated at National Naval Medical Center (NNMC) were characterized by phenotype and genotype to identify clones in this population...

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

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

    2016-01-01

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

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

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    Vanessa Cristine Kobs

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

  20. OXA-Carbapenemases Present in Clinical Acinetobacter baumannii-calcoaceticus Complex Isolates from Patients in Kurdistan Region, Iraq.

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    Ganjo, Aryann R; Maghdid, Delshad M; Mansoor, Isam Y; Kok, Dik J; Severin, Juliette A; Verbrugh, Henri A; Kreft, Deborah; Fatah, M H; Alnakshabandi, A A; Dlnya, Asad; Hammerum, Anette M; Ng, Kim; Goessens, Wil

    2016-12-01

    In addition to intrinsic resistance in Acinetobacter baumannii, many different types of acquired resistance mechanisms have been reported, including the presence of VIM and IMP metallo β-lactamases and also of bla OXA-23-like and bla OXA-58-like enzymes. In the Kurdistan region of Iraq, the multiresistant A. baumannii-calcoaceticus complex is prevalent. We characterized the different mechanisms of resistance present in clinical isolates collected from different wards and different hospitals from the Kurdistan region. One hundred twenty clinical nonduplicate A. baumannii-calcoaceticus complex isolates were collected from four hospitals between January 2012 and October 2013. The identification of the isolates was confirmed by MALDI-TOF. The susceptibility to different antibiotics was determined by disk diffusion and analyzed in accordance to EUCAST guidelines. By PCR, the presence of bla OXA-51-like , bla OXA-23-like , bla OXA-24-like , and bla OXA-58-like genes was determined as well as the presence of the insertion element ISAba1. Clonal diversity was analyzed by pulsed-field gel electrophoresis (PFGE) using the restriction enzyme ApaI and, in addition, multilocus sequence typing (MLST) was performed on a selected subset of 15 isolates. All 120 A. baumannii isolates harbored bla OXA-51-like genes. One hundred one out of 110 (92%) imipenem (IMP)-resistant A. baumannii-calcoaceticus complex isolates additionally carried the bla OXA-23-like gene and four isolates (3%) were positive for bla OXA-24-like. All 101 bla OXA-23-like -positive isolates had the ISAba1 insertion sequence, 1,600 bp upstream of the bla OXA-23-like gene. The bla OXA-58-like gene was not detected in any of the 110 IMP-resistant strains. Eight different PFGE clusters were identified and distributed over the different hospitals. MLST analysis performed on a subset of 15 representative isolates revealed the presence of the international clone ST2 (Pasteur). Besides ST2 (Pasteur), also many other

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

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    Daniel De Vos

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

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

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

    2016-01-01

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

  3. Molecular epidemiology of Acinetobacter baumannii and Acinetobacter nosocomialis in Germany over a 5-year period (2005-2009).

    Science.gov (United States)

    Schleicher, X; Higgins, P G; Wisplinghoff, H; Körber-Irrgang, B; Kresken, M; Seifert, H

    2013-08-01

    To investigate the species distribution within the Acinetobacter calcoaceticus-Acinetobacter baumannii complex and the molecular epidemiology of A. baumannii and Acinetobacter nosocomialis, 376 Acinetobacter isolates were collected prospectively from hospitalized patients at 15 medical centres in Germany during three surveillance studies conducted over a 5-year period. Species identification was performed by molecular methods. Imipenem minimum inhibitory concentrations (MIC) were determined by broth microdilution. The prevalence of the most common carbapenemase-encoding genes was investigated by oxacillinase (OXA) -multiplex polymerase chain reaction (PCR). The molecular epidemiology was investigated by repetitive sequence-based PCR (rep-PCR; DiversiLab™). Acinetobacter pittii was the most prevalent Acinetobacter species (n = 193), followed by A. baumannii (n = 140), A. calcoaceticus (n = 10) and A. nosocomialis (n = 8). The majority of A. baumannii was represented by sporadic isolates (n = 70, 50%) that showed unique rep-PCR patterns, 25 isolates (18%) clustered with one or two other isolates, and only 45 isolates (32%) belonged to one of the previously described international clonal lineages. The most prevalent clonal lineage was international clone (IC) 2 (n = 34) and IC 1 (n = 6). According to CLSI, 25 A. baumannii isolates were non-susceptible to imipenem (MIC ≥ 8 mg/L), all of which produced an OXA-58-like or OXA-23-like carbapenemase. The rate of imipenem susceptibility among A. baumannii isolates decreased from 96% in 2005 to 76% in 2009. All other Acinetobacter isolates were susceptible to imipenem. The population structure of carbapenem-susceptible A. baumannii in Germany is highly diverse. Imipenem non-susceptibility was strongly associated with the clonal lineages IC 2 and IC 1. These data underscore the high clonality of carbapenem-resistant A. baumannii isolates. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of

  4. Short communication: Multidrug-resistant Acinetobacter baumannii-calcoaceticus complex isolated from infant milk formula and utensils in a nursery in Rio de Janeiro, Brazil.

    Science.gov (United States)

    Araújo, B C; Moraes, M S; Costa, L E O; Nascimento, J S

    2015-04-01

    Infant milk formulas are not sterile products, and pathogenic bacteria can survive and multiply in these products. This study was performed, initially, to detect the presence of Salmonella spp. in reconstituted infant milk formula and on utensils previously sanitized used in their preparation or distribution in a nursery of a public hospital in Rio de Janeiro. None of the samples tested carried Salmonellaspp. However, further identification of colonies growing on the selective media revealed the presence of several other gram-negative bacteria. Seventeen isolates were identified as belonging to Acinetobacter baumannii-calcoaceticus complex. Fourteen isolates presented a multidrug-resistance profile, by disc diffusion assays, and one of them--JE4--was also resistant to imipenem. The detection of Acinetobacter isolates in this work demonstrates inadequate hygiene practices in the preparation or distribution of infant milk formula. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2014-07-01

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

  6. Endemicity of Acinetobacter calcoaceticus-baumannii Complex in an Intensive Care Unit in Malaysia

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    Amreeta Dhanoa

    2015-01-01

    Full Text Available Introduction. Acinetobacter calcoaceticus-baumannii complex (ACB complex is a leading opportunistic pathogen in intensive care units (ICUs. Effective control of spread requires understanding of its epidemiological relatedness. This study aims to determine the genetic relatedness and antibiotic susceptibilities of ACB complex in an ICU in Malaysia. Methodology. Pulsed field gel electrophoresis (PFGE, E-test, and disk diffusion were used for isolates characterization. Results. During the study period (December 2011 to June 2012, 1023 patients were admitted to the ICU and 44 ACB complex (blood, n=21, and blind bronchial aspirates, n=23 were recovered from 38 ICU patients. Six isolates were from non-ICU patients. Of the 44 ICU isolates, 88.6% exhibited multidrug-resistant (MDR patterns. There was high degree of resistance, with minimum inhibitory concentration90 (MIC90 of >32 μg/mL for carbapenems and ≥256 μg/mL for amikacin, ampicillin/sulbactam, and cefoperazone/sulbactam. Isolates from the main PFGE cluster were highly resistant. There was evidence of dissemination in non-ICU wards. Conclusion. High number of clonally related MDR ACB complex was found. While the ICU is a likely reservoir facilitating transmission, importation from other wards may be important contributor. Early identification of strain relatedness and implementation of infection control measures are necessary to prevent further spread.

  7. Screening and characterization of a novel alkaline lipase from Acinetobacter calcoaceticus 1-7 isolated from Bohai Bay in China for detergent formulation

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    Haikuan Wang

    2012-03-01

    Full Text Available A novel alkaline lipase-producing strain 1-7 identified as Acinetobacter calcoaceticus was isolated from soil samples collected from Bohai Bay, China, using an olive oil alkaline plate, which contained olive oil as the sole carbon source. The lipase from strain 1-7 showed the maximum activity at pH 9.0 under 40ºC. One interesting feature of this enzyme is that it exhibits lipase activity over a broad range of temperatures and good stability. It is also stable at a broad range of pHs from 4.0 to 10.0 for 24 h. Its catalytic activity was highly enhanced in the presence of Ca2+, Mg2+ and K+, but partially inhibited by Cu2+, Al3+, Fe3+ , Ba2+and Zn2+. The fact that it displays marked stability and activity in the presence of TritonX-100, Tween-20, Tween-80, SDS, Hydrogen peroxide, Sodium perborate, Sodium hypochlorite, Sodium citrate, Sodium taurocholate, Glycerine and NaCl suggests that this lipase is suitable as an additive in detergent formulations.

  8. Coaggregation between Rhodococcus and Acinetobacter strains isolated from the food industry.

    Science.gov (United States)

    Møretrø, Trond; Sharifzadeh, Shahab; Langsrud, Solveig; Heir, Even; Rickard, Alexander H

    2015-07-01

    In this study, coaggregation interactions between Rhodococcus and Acinetobacter strains isolated from food-processing surfaces were characterized. Rhodococcus sp. strain MF3727 formed intrageneric coaggregates with Rhodococcus sp. strain MF3803 and intergeneric coaggregates with 2 strains of Acinetobacter calcoaceticus (MF3293, MF3627). Stronger coaggregation between A. calcoaceticus MF3727 and Rhodococcus sp. MF3293 was observed after growth in batch culture at 30 °C than at 20 °C, after growth in tryptic soy broth than in liquid R2A medium, and between cells in exponential and early stationary phases than cells in late stationary phase. The coaggregation ability of Rhodococcus sp. MF3727 was maintained even after heat and Proteinase K treatment, suggesting its ability to coaggregate was protein independent whereas the coaggregation determinants of the other strains involved proteinaceous cell-surface-associated polymers. Coaggregation was stable at pH 5-9. The mechanisms of coaggregation among Acinetobacter and Rhodococcus strains bare similarity to those displayed by coaggregating bacteria of oral and freshwater origin, with respect to binding between proteinaceous and nonproteinaceous determinants and the effect of environmental factors on coaggregation. Coaggregation may contribute to biofilm formation on industrial food surfaces, protecting bacteria against cleaning and disinfection.

  9. INDUSTRIAL WASTE BIOCONVERSION INTO SURFACTANTS BY Rhodococcus erythropolis ІMV Ас-5017, Acinetobacter calcoaceticus ІMV В-7241 and Nocardia vaccinii ІMV В-7405

    Directory of Open Access Journals (Sweden)

    T. P. Pirog

    2017-04-01

    Full Text Available The aim of the work is to realize an alternative processing of toxic industrial waste into surfactants by strains Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 for remediation of environment. The studied strains were grown in liquid media containing such sources of carbon as waste (fried sunflower oil, technical glycerol (by-product of biodiesel production, and aromatic compounds. The synthesis of surfactants was evaluated by emulsification index, conditional concentration of surfactants and concentration of extracellular surfactants, which was determined gravimetrically after their extraction from supernatant by the mixture of methanol and chloroform. The concentration of oil in water and soil was analyzed by gravimetric method after extraction with hexane. It was shown that with increasing concentration of the inoculum up to 10−15% and two times increase of nitrogen source content in medium containing 7−8% (v/v of crude glycerol, concentration of surfactants synthesized by R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B 7241 and N. vaccinii IMV B-7405 was 3.4; 5.0 and 5.3 g/l, respectively, that is 1.6−1.7 times higher as compared with values on basal medium with the same content of substrate. The maximum concentration (3.9−4.3 g/l of surfactants synthesized by A. calcoaceticus IMV B-7241 on fried sunflower oil (4% was achieved by using the inoculum grown on refined oil. The ability of R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 to decompose aromatic compounds (phenol, naphthalene, toluene, hexachlorobenzene, benzoic and N-phenylanthranilic acid with simultaneous synthesis of extracellular metabolites with surface-active and emulsifying properties was established. In the presence of surfactants in the form of culture liquid (5−10%, the degree of degradation of complex oil with heavy metal (Cu2+, Cd2+, Pb2+, 0.01−0.5 mmol

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

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    R. H. González

    2009-06-01

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

  11. Enrichment of Acinetobacter spp. from food samples.

    Science.gov (United States)

    Carvalheira, Ana; Ferreira, Vânia; Silva, Joana; Teixeira, Paula

    2016-05-01

    Relatively little is known about the role of foods in the chain of transmission of acinetobacters and the occurrence of different Acinetobacter spp. in foods. Currently, there is no standard procedure to recover acinetobacters from food in order to gain insight into the food-related ecology and epidemiology of acinetobacters. This study aimed to assess whether enrichment in Dijkshoorn enrichment medium followed by plating in CHROMagar™ Acinetobacter medium is a useful method for the isolation of Acinetobacter spp. from foods. Recovery of six Acinetobacter species from food spiked with these organisms was compared for two selective enrichment media (Baumann's enrichment and Dijkshoorn's enrichment). Significantly (p enrichment. Next, the Dijkshoorn's enrichment followed by direct plating on CHROMagar™ Acinetobacter was applied to detect Acinetobacter spp. in different foods. Fourteen different presumptive acinetobacters were recovered and assumed to represent nine different strains on the basis of REP-PCR typing. Eight of these strains were identified by rpoB gene analysis as belonging to the species Acinetobacter johnsonii, Acinetobacter calcoaceticus, Acinetobacter guillouiae and Acinetobacter gandensis. It was not possible to identify the species level of one strain which may suggests that it represents a distinct species. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

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    Anton Y Peleg

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

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

    Science.gov (United States)

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

    2012-01-01

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

  14. [Effects of oil-refining microbes (genus Acinetobacter) on cytogenetical structures of human lymphocytes in cell cultures].

    Science.gov (United States)

    Il'inskikh, N N; Il'inskikh, E N; Il'inskikh, I N

    2012-01-01

    The objective of this study was to assess ability of oil-refining bacteria Acinetobacter calcoaceticus and A. valentis to induce karyopathological abnormalities and chromosomal aberrations in human lymphocyte cultures. It was found that the cultures infected with A. calcoaceticus showed significantly high frequencies of cytogenetical effects and chromosomal aberrant cells as compared to the intact cultures and cultures infected with A. valentis. The most of chromosomal aberrations, mainly chromatid aberrations, were located in 1 and 2 chromosomes. Moreover, the aberrations were detected in some specific chromosome areas. Abnormalities of mitotic cell division and nucleus morphology were determined in lymphocyte cultures infected with A. calcoaceticus. There were found significantly high frequencies of cells with micronuclei, nucleus protrusions, anaphase or metaphase chromosome and chromosomal fragments lagging as well as multipolar and C-mitoses. Thus, the oil-refining bacteria A. calcoaceticus in contrast to A. valentis demonstrated strong genotoxic effects in human lymphocyte cultures in vitro.

  15. PHEA-PLA biocompatible nanoparticles by technique of solvent evaporation from multiple emulsions.

    Science.gov (United States)

    Cavallaro, Gennara; Craparo, Emanuela Fabiola; Sardo, Carla; Lamberti, Gaetano; Barba, Anna Angela; Dalmoro, Annalisa

    2015-11-30

    Nanocarriers of amphiphilic polymeric materials represent versatile delivery systems for poorly water soluble drugs. In this work the technique of solvent evaporation from multiple emulsions was applied to produce nanovectors based on new amphiphilic copolymer, the α,β-poly(N-2-hydroxyethyl)-DL-aspartamide-polylactic acid (PHEA-PLA), purposely synthesized to be used in the controlled release of active molecules poorly soluble in water. To this aim an amphiphilic derivative of PHEA, a hydrophilic polymer, was synthesized by derivatization of the polymeric backbone with hydrophobic grafts of polylactic acid (PLA). The achieved copolymer was thus used to produce nanoparticles loaded with α tocopherol (vitamin E) adopted as lipophilic model molecule. Applying a protocol based on solvent evaporation from multiple emulsions assisted by ultrasonic energy and optimizing the emulsification process (solvent selection/separation stages), PHEA-PLA nanostructured particles with total α tocopherol entrapment efficiency (100%), were obtained. The drug release is expected to take place in lower times with respect to PLA due to the presence of the hydrophilic PHEA, therefore the produced nanoparticles can be used for semi-long term release drug delivery systems. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Czech Academy of Sciences Publication Activity Database

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

    2013-01-01

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

  17. Endemic carbapenem-nonsusceptible Acinetobacter baumannii-calcoaceticus complex in intensive care units of the national referral hospital in Jakarta, Indonesia

    NARCIS (Netherlands)

    Saharman, Y.R. (Yulia Rosa); Karuniawati, A. (Anis); Sedono, R. (Rudyanto); Aditianingsih, D. (Dita); Sudarmono, P. (Pratiwi); W.H.F. Goessens (Wil); Klaassen, C.H.W. (Corné H.W.); H.A. Verbrugh (Henri); J.A. Severin (Juliëtte)

    2018-01-01

    textabstractBackground: Carbapenem-nonsusceptible A. baumannii-calcoaceticus complex have emerged worldwide, but the epidemiology in Indonesian hospitals has not been studied. Methods: A prospective observational study was performed on the intensive care units (ICUs) of the national referral

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Science.gov (United States)

    Fitzpatrick, Margaret A.; Hauser, Alan R.

    2015-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  2. Acinetobacter calcoaceticus CSY-P13 Mitigates Stress of Ferulic and p-Hydroxybenzoic Acids in Cucumber by Affecting Antioxidant Enzyme Activity and Soil Bacterial Community

    Directory of Open Access Journals (Sweden)

    Fenghui Wu

    2018-06-01

    Full Text Available Ferulic acid (FA and p-hydroxybenzoic acid (PHBA are main phenolic compounds accumulated in rhizosphere of continuously cropped cucumber, causing stress in plants. Microbial degradation of a mixture of FA and PHBA is not well understood in soil. We isolated a strain CSY-P13 of Acinetobacter calcoaceticus, inoculated it into soil to protect cucumber from FA and PHBA stress, and explored a mechanism underlying the protection. CSY-P13 effectively degraded a mixture of FA and PHBA in culture solution under conditions of 39.37°C, pH 6.97, and 21.59 g L-1 potassium dihydrogen phosphate, giving rise to 4-vinyl guaiacol, vanillin, vanillic acid, and protocatechuic acid. During FA and PHBA degradation, activities of superoxide dismutase (SOD, catalase, ascorbate peroxidase, and dehydroascorbate reductase in CSY-P13 were induced. Inoculated into cucumber-planted soil containing 220 μg g-1 mixture of FA and PHBA, CSY-P13 degraded FA and PHBA in soil, increased plant height, and decreased malonaldehyde, superoxide radical, and hydrogen peroxide levels in leaves. CSY-P13 also enhanced SOD, guaiacol peroxidase, catalase, glutathione peroxidase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase activities; increased ascorbate and glutathione contents; and elevated transcript levels of copper/zinc SOD, manganese SOD, and catalase in leaves under FA and PHBA. Moreover, CSY-P13 increased phosphatase, catalase, urease, and sucrase activities and changed bacterial richness, diversity, and community composition by high throughput sequencing in cucumber-planted soil supplemented with the mixture of FA and PHBA. So CSY-P13 degrades the mixture of FA and PHBA in soil and mitigates stress from the two phenolic compounds in cucumber by activating antioxidant enzymes, changing soil bacterial community, and inducing soil enzymes.

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

    Directory of Open Access Journals (Sweden)

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

    Science.gov (United States)

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

    2013-01-01

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

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2013-03-15

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

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

    Science.gov (United States)

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

    2013-01-01

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

  8. Radiation resistance of clinical Acinetobacter spp.: A need for concern

    International Nuclear Information System (INIS)

    Christensen, E.A.; Gerner-Smidt, P.; Kristensen, H.

    1991-01-01

    As part of an epidemiological investigation of hospital infections caused by Acinetobacter spp. the radiation resistance of 15 clinical isolates and four reference strains was assessed. The radiation resistance (in D-6 values, viz. the dose necessary for reducing the initial number of colony forming units by a factor of 10(6)) was, in general, higher in the isolates of A. radioresistens than in the isolates of the A. calcoaceticus-A. baumannii complex and of A. lwoffi. However, the least resistant isolates of A. radioresistens had a D-6 value equal to or lower than the most resistant isolates of the other groups. The lowest D-6 values found were for two of the reference strains. The highest D-6 value was 35 kGy. Three isolates of A. johnsonii could not survive long enough in a dried preparation to make an assessment of the D-6 values possible. The radiation resistance of the 15 clinical isolates in the present study was higher than the resistance found in a study of similar isolates in 1970

  9. Radiation resistance of clinical Acinetobacter spp. : A need for concern

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, E.A.; Gerner-Smidt, P.; Kristensen, H. (Control Department, Statens Seruminstitut, Copenhagen (Denmark))

    1991-06-01

    As part of an epidemiological investigation of hospital infections caused by Acinetobacter spp. the radiation resistance of 15 clinical isolates and four reference strains was assessed. The radiation resistance (in D-6 values, viz. the dose necessary for reducing the initial number of colony forming units by a factor of 10(6)) was, in general, higher in the isolates of A. radioresistens than in the isolates of the A. calcoaceticus-A. baumannii complex and of A. lwoffi. However, the least resistant isolates of A. radioresistens had a D-6 value equal to or lower than the most resistant isolates of the other groups. The lowest D-6 values found were for two of the reference strains. The highest D-6 value was 35 kGy. Three isolates of A. johnsonii could not survive long enough in a dried preparation to make an assessment of the D-6 values possible. The radiation resistance of the 15 clinical isolates in the present study was higher than the resistance found in a study of similar isolates in 1970.

  10. Clinical strains of acinetobacter classified by DNA-DNA hybridization

    International Nuclear Information System (INIS)

    Tjernberg, I.; Ursing, J.

    1989-01-01

    A collection of Acinetobacter strains consisting of 168 consecutive clinical strains and 30 type and reference strains was studied by DNA-DNA hybridization and a few phenotypic tests. The field strains could be allotted to 13 DNA groups. By means of reference strains ten of these could be identified with groups described by Bouvet and Grimont (1986), while three groups were new; they were given the numbers 13-15. The type strain of A. radioresistens- recently described by Nishimura et al. (1988) - was shown to be a member of DNA group 12, which comprised 31 clinical isolates. Of the 19 strains of A. junii, eight showed hemolytic acitivity on sheep and human blood agar and an additional four strains on human blood agar only. Strains of this species have previously been regarded as non-hemolytic. Reciprocal DNA pairing data for the reference strains of the DNA gropus were treated by UPGMA clustering. The reference strains for A. calcoaceticus, A. baumannii and DNA groups 3 and 13 formed a cluster with about 70% relatedness within the cluster. Other DNA groups joined at levels below 60%. (author)

  11. Clinical strains of acinetobacter classified by DNA-DNA hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Tjernberg, I; Ursing, J [Department of Medical Microbiology, University of Lund, Malmoe General Hospital, Malmoe (Sweden)

    1989-01-01

    A collection of Acinetobacter strains consisting of 168 consecutive clinical strains and 30 type and reference strains was studied by DNA-DNA hybridization and a few phenotypic tests. The field strains could be allotted to 13 DNA groups. By means of reference strains ten of these could be identified with groups described by Bouvet and Grimont (1986), while three groups were new; they were given the numbers 13-15. The type strain of A. radioresistens- recently described by Nishimura et al. (1988) - was shown to be a member of DNA group 12, which comprised 31 clinical isolates. Of the 19 strains of A. junii, eight showed hemolytic acitivity on sheep and human blood agar and an additional four strains on human blood agar only. Strains of this species have previously been regarded as non-hemolytic. Reciprocal DNA pairing data for the reference strains of the DNA gropus were treated by UPGMA clustering. The reference strains for A. calcoaceticus, A. baumannii and DNA groups 3 and 13 formed a cluster with about 70% relatedness within the cluster. Other DNA groups joined at levels below 60%. (author).

  12. Immobilisation of Acinetobacter calcoaceticus using natural carriers

    African Journals Online (AJOL)

    2005-04-02

    Apr 2, 2005 ... and Cloete, 1995) or ceramic (Kariminiaae-Hamedaani et al.,. 2003) carriers. Besides the synthetic carriers, natural zeolite. (NZ) has been shown as a .... ing 9 mℓ of sterile distilled water, crushed with a sterile glass rod and dispersed by mixing (2 700 r/min for 10 min using the test tube shaker Kartell TK3S) ...

  13. Multidrug‑resistant acinetobacter infection and their susceptibility ...

    African Journals Online (AJOL)

    Results: Major infections found in different medical wards, surgical wards and ICU were due to Acinetobacter baumannii (74.02%), A. lowfii (14.2%), A. haemolyticus (7.79%), A. junii (3.8%) among Acinetobacter spices. Acinetobacter showed increased resistant against majority of commercially available drugs imipenem ...

  14. Carbapenem-Resistant Acinetobacter baumannii and Enterobacteriaceae in South and Southeast Asia

    Science.gov (United States)

    Apisarnthanarak, Anucha; Khan, Erum; Ghafur, Abdul

    2016-01-01

    SUMMARY Carbapenem-resistant Gram-negative bacteria, in particular the Acinetobacter baumannii-calcoaceticus complex and Enterobacteriaceae, are escalating global public health threats. We review the epidemiology and prevalence of these carbapenem-resistant Gram-negative bacteria among countries in South and Southeast Asia, where the rates of resistance are some of the highest in the world. These countries house more than a third of the world's population, and several are also major medical tourism destinations. There are significant data gaps, and the almost universal lack of comprehensive surveillance programs that include molecular epidemiologic testing has made it difficult to understand the origins and extent of the problem in depth. A complex combination of factors such as inappropriate prescription of antibiotics, overstretched health systems, and international travel (including the phenomenon of medical tourism) probably led to the rapid rise and spread of these bacteria in hospitals in South and Southeast Asia. In India, Pakistan, and Vietnam, carbapenem-resistant Enterobacteriaceae have also been found in the environment and community, likely as a consequence of poor environmental hygiene and sanitation. Considerable political will and effort, including from countries outside these regions, are vital in order to reduce the prevalence of such bacteria in South and Southeast Asia and prevent their global spread. PMID:27795305

  15. Carbapenem-Resistant Acinetobacter baumannii and Enterobacteriaceae in South and Southeast Asia.

    Science.gov (United States)

    Hsu, Li-Yang; Apisarnthanarak, Anucha; Khan, Erum; Suwantarat, Nuntra; Ghafur, Abdul; Tambyah, Paul Anantharajah

    2017-01-01

    Carbapenem-resistant Gram-negative bacteria, in particular the Acinetobacter baumannii-calcoaceticus complex and Enterobacteriaceae, are escalating global public health threats. We review the epidemiology and prevalence of these carbapenem-resistant Gram-negative bacteria among countries in South and Southeast Asia, where the rates of resistance are some of the highest in the world. These countries house more than a third of the world's population, and several are also major medical tourism destinations. There are significant data gaps, and the almost universal lack of comprehensive surveillance programs that include molecular epidemiologic testing has made it difficult to understand the origins and extent of the problem in depth. A complex combination of factors such as inappropriate prescription of antibiotics, overstretched health systems, and international travel (including the phenomenon of medical tourism) probably led to the rapid rise and spread of these bacteria in hospitals in South and Southeast Asia. In India, Pakistan, and Vietnam, carbapenem-resistant Enterobacteriaceae have also been found in the environment and community, likely as a consequence of poor environmental hygiene and sanitation. Considerable political will and effort, including from countries outside these regions, are vital in order to reduce the prevalence of such bacteria in South and Southeast Asia and prevent their global spread. Copyright © 2016 American Society for Microbiology.

  16. Emergence of New Delhi metallo-beta-lactamase 1 and other carbapenemase-producing Acinetobacter calcoaceticus-baumannii complex among patients in hospitals in Ha Noi, Viet Nam

    NARCIS (Netherlands)

    Tran, D.N.; Tran, H.H.; Matsui, M.; Suzuki, M.; Suzuki, S.; Shibayama, K.; Pham, T.D.; Phuong, T.T. Van; Dang, D.A.; Trinh, H.S.; Loan, C.T.; Nga, L.T.; Doorn, H.R. van; Wertheim, H.F.L.

    2017-01-01

    Acinetobacter baumannii is an important cause of multidrug-resistant hospital acquired infections in the world. Here, we investigate the presence of NDM-1 and other carbapenemases among carbapenem-resistant A. baumannii isolated between August 2010 and December 2014 from three large hospitals in

  17. Delayed identification of Acinetobacter baumannii during an outbreak owing to disrupted blaOXA-51-like by ISAba19.

    Science.gov (United States)

    Ahmadi, Amjad; Salimizand, Himen

    2017-07-01

    Early detection of Acinetobacter baumannii, an emerging pathogen in hospital settings, is of interest. The bla OXA-51-like family had been used as a marker to detect A. baumannii. During an infection outbreak, 14 isolates produced a 1.7-kb PCR band instead of 353 bp for this marker. This work sought the reasons behind the increased marker size. Characterisation of isolates was done by API-20NE, gyrB multiplex PCR and 16S-23S rRNA ITS sequencing. The 1.7-kb band generated and the complete bla OXA-51-like variant were sequenced to find the probable integrated element. Susceptibility testing to various antimicrobials was performed by microdilution. bla OXA-like , metallo-β-lactamases (MBLs), the ISAba1 element and the presence of ISAba1 adjacent to bla OXA-like were sought. rep-PCR, global clonal (GC) lineage determination and multilocus sequence typing (MLST) were performed to analyse the relationship among isolates. Isolates were characterised as Acinetobacter baumannii-calcoaceticus complex by API-20NE. gyrB multiplex PCR and 16S-23S ITS sequencing verified the isolates as A. baumannii. Sequencing of the 1.7-kb band revealed ISAba19 as the disrupting element. The bla OXA-51 variant was bla OXA-66 , which was elongated to 2.2 kb due to ISAba19. The bla OXA-23-like family was found in 67% of isolates. MBL genes were not detected; however, ISAba1-bla OXA-23-like was characterised in carbapenem-resistant isolates (53%; 8/15). Isolates were divided into three clusters by rep-PCR. All strains were ST2 and all but one belonged to GC II. Identification of A. baumannii based only on bla OXA-51-like is not reliable. Besides bla OXA-51-like , multiplex PCR of gyrB and rpoB could provide rapid and cost-effective results. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  18. 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

    Directory of Open Access Journals (Sweden)

    M. S. Ramírez

    2010-06-01

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

  19. Comparative Analysis of 37 Acinetobacter Bacteriophages

    Directory of Open Access Journals (Sweden)

    Dann Turner

    2017-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-25

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

  1. Reservoirs of Non-baumannii Acinetobacter Species

    Science.gov (United States)

    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

  2. Clinical and economic outcomes of Acinetobacter vis a vis non-Acinetobacter infections in an Indian teaching hospital

    Directory of Open Access Journals (Sweden)

    Priyendu Asim

    2016-01-01

    Full Text Available Context: Acinetobacter infections are a major nosocomial infection causing epidemics of infection in the Intensive Care Units (ICU. Aims: This study estimates the clinical and economic outcomes of Acinetobacter infections and compares them with those of non-Acinetobacter bacterial infections. Settings and Design: Prospective cross-sectional observational study carried out for 6 months in the medicine ICU of a tertiary care hospital. Materials and Methods: Patients were divided in two groups, one group with Acinetobacter infections and the other with non-Acinetobacter infections. The data was collected for infection, length of stay (LOS, mortality and cost along with patient demographics from the hospital records for analysis. Statistical Analysis Used: The data was analyzed using Statistical Package for the Social Sciences Version 15.0. The LOS and cost of treatment (COT for the two groups were compared using the nonparametric Mann–Whitney U-test. Results: A total of 220 patients were studied out of which 91 had Acinetobacter infections. The median LOS was 20 days in Group-A and 12 days in Group-B (P < 0.0001. The median COT was INR 125,862 in Group-A and INR 68,228 in the Group-B (P < 0.0001. Mortality in Group-A and Group-B was 32.97 and 32.56 (P = 0.949 respectively. Conclusion: The burden of Acinetobacter infections in ICUs is increasing with the increase in LOS and COT for the patients. The infection control team has to play a major role in reducing the rate of nosocomial infections.

  3. Drug-resistant post-neurosurgical nosocomial Acinetobacter ...

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

    Talaga, Katarzyna; Krzyściak, Paweł; Bulanda, Małgorzata

    2016-01-01

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

  5. 21 CFR 866.3010 - Acinetobacter calcoaceticus serological reagents.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3010... this bacterium from cultured isolates derived from clinical specimens. The identification aids in the...

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

    International Nuclear Information System (INIS)

    Tahseen, U.; Talib, M.T.

    2015-01-01

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

  7. A new double digestion ligation mediated suppression PCR method for simultaneous bacteria DNA-typing and confirmation of species: an Acinetobacter sp. model.

    Directory of Open Access Journals (Sweden)

    Karolina Stojowska

    Full Text Available We have designed a new ddLMS PCR (double digestion Ligation Mediated Suppression PCR method based on restriction site polymorphism upstream from the specific target sequence for the simultaneous identification and differentiation of bacterial strains. The ddLMS PCR combines a simple PCR used for species or genus identification and the LM PCR strategy for strain differentiation. The bacterial identification is confirmed in the form of the PCR product(s, while the length of the PCR product makes it possible to differentiate between bacterial strains. If there is a single copy of the target sequence within genomic DNA, one specific PCR product is created (simplex ddLMS PCR, whereas for multiple copies of the gene the fingerprinting patterns can be obtained (multiplex ddLMS PCR. The described ddLMS PCR method is designed for rapid and specific strain differentiation in medical and microbiological studies. In comparison to other LM PCR it has substantial advantages: enables specific species' DNA-typing without the need for pure bacterial culture selection, is not sensitive to contamination with other cells or genomic DNA, and gives univocal "band-based" results, which are easy to interpret. The utility of ddLMS PCR was shown for Acinetobacter calcoaceticus-baumannii (Acb complex, the genetically closely related and phenotypically similar species and also important nosocomial pathogens, for which currently, there are no recommended methods for screening, typing and identification. In this article two models are proposed: 3' recA-ddLMS PCR-MaeII/RsaI for Acb complex interspecific typing and 5' rrn-ddLMS PCR-HindIII/ApaI for Acinetobacter baumannii intraspecific typing. ddLMS PCR allows not only for DNA-typing but also for confirmation of species in one reaction. Also, practical guidelines for designing a diagnostic test based on ddLMS PCR for genotyping different species of bacteria are provided.

  8. A new double digestion ligation mediated suppression PCR method for simultaneous bacteria DNA-typing and confirmation of species: an Acinetobacter sp. model.

    Science.gov (United States)

    Stojowska, Karolina; Krawczyk, Beata

    2014-01-01

    We have designed a new ddLMS PCR (double digestion Ligation Mediated Suppression PCR) method based on restriction site polymorphism upstream from the specific target sequence for the simultaneous identification and differentiation of bacterial strains. The ddLMS PCR combines a simple PCR used for species or genus identification and the LM PCR strategy for strain differentiation. The bacterial identification is confirmed in the form of the PCR product(s), while the length of the PCR product makes it possible to differentiate between bacterial strains. If there is a single copy of the target sequence within genomic DNA, one specific PCR product is created (simplex ddLMS PCR), whereas for multiple copies of the gene the fingerprinting patterns can be obtained (multiplex ddLMS PCR). The described ddLMS PCR method is designed for rapid and specific strain differentiation in medical and microbiological studies. In comparison to other LM PCR it has substantial advantages: enables specific species' DNA-typing without the need for pure bacterial culture selection, is not sensitive to contamination with other cells or genomic DNA, and gives univocal "band-based" results, which are easy to interpret. The utility of ddLMS PCR was shown for Acinetobacter calcoaceticus-baumannii (Acb) complex, the genetically closely related and phenotypically similar species and also important nosocomial pathogens, for which currently, there are no recommended methods for screening, typing and identification. In this article two models are proposed: 3' recA-ddLMS PCR-MaeII/RsaI for Acb complex interspecific typing and 5' rrn-ddLMS PCR-HindIII/ApaI for Acinetobacter baumannii intraspecific typing. ddLMS PCR allows not only for DNA-typing but also for confirmation of species in one reaction. Also, practical guidelines for designing a diagnostic test based on ddLMS PCR for genotyping different species of bacteria are provided.

  9. Acinetobacter spp. as nosocomial pathogens: Epidemiology and resistance features

    Directory of Open Access Journals (Sweden)

    Saad B. Almasaudi

    2018-03-01

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

  10. Pathogenic Acinetobacter: from the Cell Surface to Infinity and Beyond

    Science.gov (United States)

    Weber, Brent S.; Harding, Christian M.

    2015-01-01

    The genus Acinetobacter encompasses multiple nosocomial opportunistic pathogens that are of increasing worldwide relevance because of their ability to survive exposure to various antimicrobial and sterilization agents. Among these, Acinetobacter baumannii, Acinetobacter nosocomialis, and Acinetobacter pittii are the most frequently isolated in hospitals around the world. Despite the growing incidence of multidrug-resistant Acinetobacter spp., little is known about the factors that contribute to pathogenesis. New strategies for treating and managing infections caused by multidrug-resistant Acinetobacter strains are urgently needed, and this requires a detailed understanding of the pathobiology of these organisms. In recent years, some virulence factors important for Acinetobacter colonization have started to emerge. In this review, we focus on several recently described virulence factors that act at the bacterial surface level, such as the capsule, O-linked protein glycosylation, and adhesins. Furthermore, we describe the current knowledge regarding the type II and type VI secretion systems present in these strains. PMID:26712938

  11. Phenotypic and genetic relationship of Acinetobacter Baumannii isolates.

    Science.gov (United States)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  13. Nanoparticles for Control of Biofilms of Acinetobacter Species

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    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.

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

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    Azizun Nahar

    2012-01-01

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

  15. CARBAPENEM-RESISTANT ACINETOBACTER BAUMANII POSTOPERATIVE MENINGITIS

    OpenAIRE

    Laura Ghibu; Egidia Miftode; Olivia Dorneanu; Carmen Dorobat

    2011-01-01

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

  16. Nanoparticles based on novel amphiphilic polyaspartamide copolymers

    International Nuclear Information System (INIS)

    Craparo, Emanuela Fabiola; Teresi, Girolamo; Ognibene, Maria Chiara; Casaletto, Maria Pia; Bondi, Maria Luisa; Cavallaro, Gennara

    2010-01-01

    In this article, the synthesis of two amphiphilic polyaspartamide copolymers, useful to obtain polymeric nanoparticles without using surfactants or stabilizing agents, is described. These copolymers were obtained starting from α,β-poly-(N-2-hydroxyethyl)-dl-aspartamide (PHEA) by following a novel synthetic strategy. In particular, PHEA and its pegylated derivative (PHEA-PEG 2000 ) were functionalized with poly(lactic acid) (PLA) through 1,1'-carbonyldiimidazole (CDI) activation to obtain PHEA-PLA and PHEA-PEG 2000 -PLA graft copolymers, respectively. These copolymers were properly purified and characterized by 1 H-NMR, FT-IR, and Size Exclusion Chromatography (SEC) analyses, which confirmed that derivatization reactions occurred. Nanoparticles were obtained from PHEA-PLA and PHEA-PEG 2000 -PLA graft copolymers by using the high pressure homogenization-solvent evaporation method, avoiding the use of surfactants or stabilizing agents. Polymeric nanoparticles were characterized by dimensional analysis, before and after freeze-drying process, and Scanning Electron Microscopy (SEM). Zeta potential measurements and X-ray Photoelectron Spectroscopy (XPS) analysis demonstrated the presence of PEG and/or PHEA onto the PHEA-PEG 2000 -PLA and PHEA-PLA nanoparticle surface, respectively.

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

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    Kais Kassim Ghaima

    2018-04-01

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

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

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    İsa Yıldız

    2016-09-01

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

  19. Acinetobacter phage genome is similar to Sphinx 2.36, the circular DNA copurified with TSE infected particles.

    Science.gov (United States)

    Longkumer, Toshisangba; Kamireddy, Swetha; Muthyala, Venkateswar Reddy; Akbarpasha, Shaikh; Pitchika, Gopi Krishna; Kodetham, Gopinath; Ayaluru, Murali; Siddavattam, Dayananda

    2013-01-01

    While analyzing plasmids of Acinetobacter sp. DS002 we have detected a circular DNA molecule pTS236, which upon further investigation is identified as the genome of a phage. The phage genome has shown sequence similarity to the recently discovered Sphinx 2.36 DNA sequence co-purified with the Transmissible Spongiform Encephalopathy (TSE) particles isolated from infected brain samples collected from diverse geographical regions. As in Sphinx 2.36, the phage genome also codes for three proteins. One of them codes for RepA and is shown to be involved in replication of pTS236 through rolling circle (RC) mode. The other two translationally coupled ORFs, orf106 and orf96, code for coat proteins of the phage. Although an orf96 homologue was not previously reported in Sphinx 2.36, a closer examination of DNA sequence of Sphinx 2.36 revealed its presence downstream of orf106 homologue. TEM images and infection assays revealed existence of phage AbDs1 in Acinetobacter sp. DS002.

  20. MICROBIAL SURFACTANTS. I. GLYCOLIPIDS

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    Pirog T. Р.

    2014-02-01

    Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.

  1. [Community-acquired Acinetobacter pneumonia].

    Science.gov (United States)

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

    1993-08-21

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

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

    Science.gov (United States)

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

    2015-07-01

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

  3. Emerging Trend of Acinetobacter Nosocomial Infection in Northeast of Iran

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    Samaneh Saed

    2015-10-01

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

  4. Detection of blaOXA-23-like and blaNDM-1 in Acinetobacter baumannii from the Eastern Region, Saudi Arabia.

    Science.gov (United States)

    El-Mahdy, Taghrid S; Al-Agamy, Mohamed H; Al-Qahtani, Ahmed A; Shibl, Atef M

    2017-01-01

    Acinetobacter baumannii is currently considered as one of the most common successful pathogens in the healthcare system due to its ability to quickly develop resistance. Ten carbapenem-resistant A. calcoaceticus-baumannii complex were isolated from the eastern region, Saudi Arabia in 2014. All isolates were resistant to ciprofloxacin, however, 8 of 10 isolates were tigecycline resistant. Susceptibility test was also carried out for three aminoglycosides, resistance to gentamicin was 80%, amikacin was 90%, and tobramycin was 50%. Colistin susceptibility was seen in all isolates. The 10 isolates harbored bla OXA-23-like and ISAba1 and 9 of them also carried bla ADC . Three isolates of 10 harbored bla NDM-1 coding for NDM metallo-β-lactamase (MBL) with coexistence of bla ADC together with either bla GES or bla TEM or both. Those three isolates exhibited negative Etest MBL screening test. Pulsed-field gel electrophoresis revealed the high clonal variability of the isolates, although two isolates were indistinguishable. The risk of dissemination of carbapenem resistance through presence of ISAba1 upstream of OXA-23-like in all isolates raises the concern about emergence of higher carbapenem prevalence rates in the future in our region. This study also demonstrated the importance of molecular surveillance to provide accurate and reliable data about the resistance rates of A. baumannii. Finally, the high incidence of NDM-1 among our isolates requires a routine surveillance to monitor the future prevalence of this enzyme in the region.

  5. Polyaspartamide-Polylactide Graft Copolymers with Tunable Properties for the Realization of Fluorescent Nanoparticles for Imaging.

    Science.gov (United States)

    Craparo, Emanuela Fabiola; Porsio, Barbara; Mauro, Nicolò; Giammona, Gaetano; Cavallaro, Gennara

    2015-08-01

    Here, the synthesis and the characterization of novel amphiphilic graft copolymers with tunable properties, useful in obtaining polymeric fluorescent nanoparticles for application in imaging, are described. These copolymers are obtained by chemical conjugation of rhodamine B (RhB) moieties, polylactic acid (PLA), and O-(2-aminoethyl)-O'-methyl poly(ethylene glycol) (PEG) on α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). In particular, PHEA is first functionalized with RhB to obtain PHEA-RhB with a derivatization degree in RhB (DDRhB ) equal to 0.55 mol%. By varying the reaction conditions, different amounts of PLA are grafted on PHEA-RhB to obtain PHEA-RhB-PLA with DDPLA equal to 1.9, 4.0, and 6.2 mol%. Then, PEG chains are grafted on PHEA-RhB-PLA derivatives to obtain PHEA-RhB-PLA-PEG graft copolymers. The preparation of polymeric fluorescent nanoparticles with tunable properties and spherical shape is described by using PHEA-RhB-PLA-PEG with DD in PLA and PEG equal to 4.0 and 4.9 mol%, by following easily scaling up processes, such as emulsion-solvent evaporation and high pressure homogenization (HPH)-solvent evaporation techniques. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    African Journals Online (AJOL)

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

  7. Acinetobacter Peritoneal Dialysis Peritonitis: A Changing Landscape over Time

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  9. The role of Acinetobacter in the pathogenesis of multiple sclerosis examined by using Popper sequences.

    Science.gov (United States)

    Ebringer, Alan; Rashid, Taha; Wilson, Clyde

    2012-06-01

    Multiple sclerosis (MS) is an autoimmune neurological disorder. The role of 'Acinetobacter' has been examined using the method of Karl Popper and involves nine "Popper sequences". (1) The frequency of MS increases with latitudes in the Northern Hemisphere, and the reverse is found in the Southern Hemisphere. (2) Sinusitis is found frequently at colder latitudes. (3) Sinusitis occurs frequently in patients with MS. (4) Specific sequences of bovine myelin when injected into experimental animals will produce a neurological disorder resembling MS which is called "experimental allergic encephalomyelitis". (5) Computer analysis of myelin shows molecular mimicry with sequences found in Acinetobacter. (6) Antibodies to Acinetobacter bacteria are found in MS patients. (7) Acinetobacter bacteria are located on human skin and in the nasal sinuses. (8) IgA antibodies are preferentially elevated in the sera of MS patients, thereby suggesting the trigger microbe is acting across a mucosal surface probably located in the nasal sinuses. (9) Only Acinetobacter bacteria and no other microbes evoke statistically significant titres of antibodies in MS patients. These nine Popper sequences suggest that MS is most probably caused by infections with Acinetobacter bacteria in the nasal sinuses, and this could have therapeutic implications. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

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    Edis Ebru

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Shaheda Anwar

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

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    Purti C Tripathi

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Rosić Ivana

    2013-01-01

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

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

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    Yesim Cekin

    2014-03-01

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

  19. Bacterial desorption from food container and food processing surfaces.

    Science.gov (United States)

    McEldowney, S; Fletcher, M

    1988-03-01

    The desorption ofStaphylococcus aureus, Acinetobacter calcoaceticus, and a coryneform from the surfaces of materials used for manufacturing food containers (glass, tin plate, and polypropylene) or postprocess canning factory conveyor belts (stainless steel and nylon) was investigated. The effect of time, pH, temperature, and adsorbed organic layers on desorption was studied.S. aureus did not detach from the substrata at any pH investigated (between pH 5 and 9).A. calcoaceticus and the coryneform in some cases detached, depending upon pH and substratum composition. The degree of bacterial detachment from the substrata was not related to bacterial respiration at experimental pH values. Bacterial desorption was not affected by temperature (4-30°C) nor by an adsorbed layer of peptone and yeast extract on the substrata. The results indicate that bacterial desorption, hence bacterial removal during cleaning or their transfer via liquids flowing over colonized surfaces, is likely to vary with the surface composition and the bacterial species colonizing the surfaces.

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

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    Dann Turner

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

  1. Emergence of New Delhi metallo-beta-lactamase 1 and other carbapenemase-producing Acinetobacter calcoaceticus-baumannii complex among patients in hospitals in Ha Noi, Viet Nam.

    Science.gov (United States)

    Tran, D N; Tran, H H; Matsui, M; Suzuki, M; Suzuki, S; Shibayama, K; Pham, T D; Van Phuong, T T; Dang, D A; Trinh, H S; Loan, C T; Nga, L T V; van Doorn, H R; Wertheim, H F L

    2017-02-01

    Acinetobacter baumannii is an important cause of multidrug-resistant hospital acquired infections in the world. Here, we investigate the presence of NDM-1 and other carbapenemases among carbapenem-resistant A. baumannii isolated between August 2010 and December 2014 from three large hospitals in Hanoi, Vietnam. We identified 23/582 isolates (4 %) (11 from hospital A, five from hospital B, and seven from hospital C) that were NDM-1 positive, and among them 18 carried additional carbapenemase genes, including seven isolates carrying NDM-1, IMP-1, and OXA-58 with high MICs for carbapenems. Genotyping indicated that NDM-1 carrying A. baumannii have expanded clonally in these hospitals. Five new STs (ST1135, ST1136, ST1137, ST1138, and ST1139) were identified. One isolate carried NDM-1 on a plasmid belonging to the N-repA replicon type; no NDM-1-positive plasmids were identified in the other isolates. We have shown the extent of the carbapenem resistance and the local clonal spread of A. baumannii carrying NDM-1 in these hospitals; coexistence of NDM-1 and IMP-1 is reported for the first time from Vietnam here, and this will further seriously limit future therapeutic options.

  2. Acinetobacter infections prevalence and frequency of the antibiotics ...

    African Journals Online (AJOL)

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

  3. Emergence and Spread of Plasmid-Borne tet(B)::ISCR2 in Minocycline-Resistant Acinetobacter baumannii Isolates

    OpenAIRE

    Vilacoba, Elisabet; Almuzara, Marisa; Gulone, Lucía; Traglia, German Matias; Figueroa, Silvia A.; Sly, Gabriela Edith; Fernandez, Analia; Centron, Daniela; Ramirez, Maria Soledad

    2015-01-01

    Resistance to minocycline has emerged in multidrug-resistant Acinetobacter baumannii isolates from Buenos Aires Hospitals. Few reports about the description and dispersion of tet genes were published in this species. We observed the presence of tet(B) in all minocycline resistant isolates. This gene was found associated to the ISCR2 mobile element, which could in part explain its dispersion. Fil: Vilacoba, Elisabet. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Co...

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

    African Journals Online (AJOL)

    ANTHONY

    2012-07-31

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

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

    Science.gov (United States)

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

    2016-01-01

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

  6. Molecular analysis of imipenem-resistant Acinetobacter baumannii isolated from US service members wounded in Iraq, 2003–2008

    Science.gov (United States)

    Clonal spread and global dissemination of imipenem resistant (IR) A. baumannii-A. calcoaceticus complex (ABC) have been reported in recent years. However, the epidemiological features of the IR-ABCs in military treatment facilities (MTFs) have not been systematically studied. In this study, 298 ABC...

  7. The Antibacterial Activity Evaluation of the Nanoparticles of Silver on Acinetobacter Baumannii

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    Seyedeh Nasim Karimipour

    2016-09-01

    Full Text Available Background & Objective: Due to the high drug resistance in Acinetobacter baumannii, in this research, antibacterial properties of nano silver was evaluated for Acinetobacter baumannii. Materials & Methods: The nano silver with approximate diameter of 20 nanometer from Pishtazan Inc. Mashad, Iran and 5 nanometer from the Department of Chemistry in Maragheh University were prepared. Its concentration was determined by spectroscopy method in Tabriz Chemistry University.  Antimicrobial effects were determined by Mean Inhibitory Concentration (MIC and Minimal Bacterial Concentration (MBC by micro-broth-dilution method, disc diffusion and well diffusion methods. Anti-bacterial activity of nano-silver was tested for Acinetobacter baumannii NCTC12516 on 20 clinical strains (collected from Imam Reza Hospital in Tabriz. Results: The results showed the MIC and MBC of 20nm nanoparticles were 1250 ppm and 2500 ppm, respectively. On the other hand, the MIC and MBC of 5 nm nanoparticles were 156 ppm and 312 ppm, respectively. According to these findings, the MIC and MBC identified for clinical Acinetobacter baumannii strains under study along with the NCTC12516 strain did not show a significant difference. Yet the amount of inhibition for the 20nm nanoparticles in the density of 20000 ppm of clinical Acinetobacter baumannii and NCTC12516 strains was 11 millimeter with the disc diffusion method and 9.5 millimeter for the well diffusion method with the same concentration. The amount of inhibition of 5nm nanoparticles in the 250-ppm concentration with both disc diffusion and well diffusion methods was 9.5 millimeter. Conclusions: Acinetobacter baumannii is susceptible to nano-silver. Also the same MIC and MBC in multiple clinical strains suggests that there is not resistance to silver nanoparticles in Acinetobacter baumannii

  8. Acinetobacter: environmental and biotechnological applications ...

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

    Jung, Jaejoon; Park, Woojun

    2015-03-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

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

    Directory of Open Access Journals (Sweden)

    Andrés F. Henao-Martínez

    2012-06-01

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

  12. Molecular characteristics of Multidrug Resistant Acinetobacter baumannii Isolates from US soldiers from Iraq at the National Naval Medical Center

    Science.gov (United States)

    Background: Infections with A. baumannii-calcoaceticus complex (ABC) have complicated the care of combat casualties, and the spread and global dissemination of imipenem resistant (IR) clones of ABC have been reported in recent years. However, the epidemiological features of the IR-ABCs in military t...

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

    Science.gov (United States)

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

    2018-02-01

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

  14. Effect of multipurpose solutions against Acinetobacter carrying QAC genes.

    Science.gov (United States)

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

    2014-03-01

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

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

  18. Biochemical Characterization of Lipases Obtained from Acinetobacter psychrotolerans Strains

    Directory of Open Access Journals (Sweden)

    Şule SEREN

    2017-12-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Porphyrin-containing polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Yan, Guo-Ping; Li, Zhen; Xu, Wei; Zhou, Cheng-Kai; Yang, Lian; Zhang, Qiao; Li, Liang; Liu, Fan; Han, Lin; Ge, Yuan-Xing; Guo, Jun-Fang

    2011-04-04

    Porphyrin-containing polyaspartamide ligands (APTSPP-PHEA-DTPA) were synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin, trisodium salt (APTSPP) into poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA). These ligands were further reacted with gadolinium chloride to produce macromolecule-gadolinium complexes (APTSPP-PHEA-DTPA-Gd). Experimental data of (1)H NMR, IR, UV and elemental analysis evidenced the formation of the polyaspartamide ligands and gadolinium complexes. In vitro and in vivo property tests indicated that APTSPP-PHEA-DTPA-Gd possessed noticeably higher relaxation effectiveness, less toxicity to HeLa cells, and significantly higher enhanced signal intensities (SI) of the VX2 carcinoma in rabbits with lower injection dose requirement than that of Gd-DTPA. Moreover, APTSPP-PHEA-DTPA-Gd was found to greatly enhance the contrast of MR images of the VX2 carcinoma, providing prolonged intravascular duration, and distinguished the VX2 carcinoma and normal tissues in rabbits according to MR image signal enhancements. These porphyrin-containing polyaspartamide gadolinium complexes can be used as the candidates of contrast agents for targeted MRI to tumors. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2012-04-01

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

  2. Biodistribution of newly synthesized PHEA-based polymer-coated SPION in Sprague Dawley rats as magnetic resonance contrast agent

    Directory of Open Access Journals (Sweden)

    Park J

    2013-10-01

    Full Text Available Junsung Park,1,2,* Wonkyung Cho,1,2,* Hee Jun Park,1,2 Kwang-Ho Cha,1,2 Dae-Chul Ha,2,5 Youn-Woong Choi,5 Ha-Young Lee,3 Sun-Hang Cho,5 Sung-Joo Hwang1,4 1Yonsei Institute of Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea; 2College of Pharmacy, Chungnam National University, Daejeon, Republic of Korea; 3Biomaterials Laboratory, Korea Research Institutes of Chemical Technology, Daejeon, Republic of Korea; 4College of Pharmacy, Yonsei University, Incheon, Republic of Korea; 5Korea United Pharm Inc, Seoul, Republic of Korea *These authors contributed equally to this work Objectives: The purpose of this study was to observe the pharmacokinetic behavior of newly synthesized biocompatible polymers based on polyhydroxyethylaspartamide (PHEA to be used to coat an iron oxide core to make superparamagnetic iron oxide nanoparticles (SPION. Materials and methods: The isotopes [14C] and [59Fe] were used to label the polymer backbone (CLS and iron oxide core (FLS, respectively. In addition, unradiolabeled cold superparamagnetic iron oxide nanoparticles (SPION/ULS were synthesized to characterize particle size by dynamic light scattering, morphology by transmission electron microscopy, and in vivo magnetic resonance imaging (MRI. CLS and FLS were used separately to investigate the behavior of both the synthesized polymer and [Fe] in Sprague Dawley (SD rats, respectively. Because radioactivity of the isotopes was different by β for CLS and γ for FLS, synthesis of the samples had to be separately prepared. Results: The mean particle size of the ULS was 66.1 nm, and the biodistribution of CLS concentrations in various organs, in rank order of magnitude, was liver > kidney > small intestine > other. The biodistribution of FLS concentrations was liver > spleen > lung > other. These rank orders show that synthesized SPION mainly accumulates in the liver. The differences in the distribution were caused by the SPION metabolism. Radiolabeled

  3. Molecular characterization of carbapenem-resistant Acinetobacter ...

    African Journals Online (AJOL)

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

  4. Nosocomial imipenem-resistant Acinetobacter baumannii infections ...

    African Journals Online (AJOL)

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

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

    OpenAIRE

    Evita Mayasari; Cherry Siregar

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Peter Klotz

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

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Bersissa Kumsa

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

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

    Science.gov (United States)

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

    2012-01-01

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

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

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    Shaheda Anwar

    2010-07-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

  13. Pre-hospital emergency anaesthesia in awake hypotensive trauma patients: beneficial or detrimental?

    Science.gov (United States)

    Crewdson, K; Rehn, M; Brohi, K; Lockey, D J

    2018-04-01

    The benefits of pre-hospital emergency anaesthesia (PHEA) are controversial. Patients who are hypovolaemic prior to induction of anaesthesia are at risk of severe cardiovascular instability post-induction. This study compared mortality for hypovolaemic trauma patients (without major neurological injury) undergoing PHEA with a patient cohort with similar physiology transported to hospital without PHEA. A retrospective database review was performed to identify patients who were hypotensive on scene [systolic blood pressure (SBP) < 90 mmHg], and GCS 13-15. Patient records were reviewed independently by two pre-hospital clinicians to identify the likelihood of hypovolaemia. Primary outcome measure was mortality defined as death before hospital discharge. Two hundred and thirty-six patients were included; 101 patients underwent PHEA. Fifteen PHEA patients died (14.9%) compared with six non-PHEA patients (4.4%), P = 0.01; unadjusted OR for death was 3.73 (1.30-12.21; P = 0.01). This association remained after adjustment for age, injury mechanism, heart rate and hypovolaemia (adjusted odds ratio 3.07 (1.03-9.14) P = 0.04). Fifty-eight PHEA patients (57.4%) were hypovolaemic prior to induction of anaesthesia, 14 died (24%). Of 43 PHEA patients (42.6%) not meeting hypovolaemia criteria, one died (2%); unadjusted OR for mortality was 13.12 (1.84-578.21). After adjustment for age, injury mechanism and initial heart rate, the odds ratio for mortality remained significant at 9.99 (1.69-58.98); P = 0.01. Our results suggest an association between PHEA and in-hospital mortality in awake hypotensive trauma patients, which is strengthened when hypotension is due to hypovolaemia. If patients are hypovolaemic and awake on scene it might, where possible, be appropriate to delay induction of anaesthesia until hospital arrival. © 2018 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  14. Acinetobacter baumannii in Localised Cutaneous Mycobacteriosis in Falcons

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    Margit Gabriele Muller

    2010-01-01

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

  15. Non-susceptibility trends among Pseudomonas aeruginosa and other non-fermentative Gram-negative bacteria from bacteraemias in the UK and Ireland, 2001-06.

    Science.gov (United States)

    Livermore, David M; Hope, Russell; Brick, Geraldine; Lillie, Mark; Reynolds, Rosy

    2008-11-01

    Pseudomonas and Acinetobacter spp. are important opportunists, notorious for resistance. Pseudomonas spp. are collected in the British Society for Antimicrobial Chemotherapy (BSAC) bacteraemia surveillance, with Acinetobacter spp. and Stenotrophomonas maltophilia well represented in the 'other Gram-negatives' group. Data for collected isolates were reviewed together with LabBase bacteraemia reports to the Health Protection Agency (HPA). Isolates with unusual resistances were subjected to molecular investigation. From 2001 to 2006, the BSAC surveillance collected 1226 Pseudomonas aeruginosa, 240 Acinetobacter spp.-125 of them Acinetobacter calcoaceticus/baumannii (Acb) complex-and 165 S. maltophilia. Among P. aeruginosa, non-susceptibility rates to beta-lactams and gentamicin fluctuated, without trend, below 10%; those to ciprofloxacin ranged from 16% to 22%. One P. aeruginosa isolate from 2001 had VIM-2 metallo-beta-lactamase. For Acb, the BSAC data indicated frequent non-susceptibility, except to imipenem, where only five non-susceptible isolates were collected, all after 2003, four of them belonging to the OXA-23 clone 1 lineage which is prevalent in Southeast England. Reports to the HPA indicated rising imipenem non-susceptibility in Acb (P /=16 mg/L for Acb OXA-23 clone 1. Ceftobiprole had higher MICs than ceftazidime for P. aeruginosa, but 81% of the isolates were inhibited at

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

    Directory of Open Access Journals (Sweden)

    S. Montaña

    2018-01-01

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

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

    Science.gov (United States)

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

    2008-04-01

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

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

    Science.gov (United States)

    Mortensen, Brittany L.; Skaar, Eric P.

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Fahimeh Nourbakhsh

    2017-01-01

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

  20. Multidrug Resistant Acinetobacter Infection and Their Antimicrobial ...

    African Journals Online (AJOL)

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

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

    Science.gov (United States)

    Hasan, M J; Shamsuzzaman, S M

    2017-12-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Science.gov (United States)

    2012-07-07

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

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

    Science.gov (United States)

    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.

  6. Genome Sequence of Jumbo Phage vB_AbaM_ME3 of Acinetobacter baumanni

    OpenAIRE

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Sulfonated amphiphilic block copolymers : synthesis, self-assembly in water, and application as stabilizer in emulsion polymerization

    Science.gov (United States)

    Jiguang Zhang; Matthew R. Dubay; Carl J. Houtman; Steven J. Severtson

    2009-01-01

    Described is the synthesis of diblock copolymers generated via sequential atom transfer radical polymerization (ATRP) of poly(n-butyl acrylate) (PnBA) followed by chain augmentation with either sulfonated poly(2-hydroxyethyl methacrylate) (PHEMA) or poly(2-hydroxyethyl acrylate) (PHEA) blocks. ATRP of PHEMA or PHEA from PnBA macroinitiator was conducted in acetone/...

  9. Antimicrobial resistance and clonality in Acinetobacter baumannii

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    Evita Mayasari

    2014-05-01

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

  11. Genome Sequence of Jumbo Phage vB_AbaM_ME3 of Acinetobacter baumanni.

    Science.gov (United States)

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

    2016-08-25

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

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

    Science.gov (United States)

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

    2014-01-09

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

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    Songzhe eHE

    2015-05-01

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

  15. Biocompatible Polyhydroxyethylaspartamide-based Micelles with Gadolinium for MRI Contrast Agents

    Directory of Open Access Journals (Sweden)

    Kim Hyo Jeong

    2010-01-01

    Full Text Available Abstract Biocompatible poly-[N-(2-hydroxyethyl-d,l-aspartamide]-methoxypoly(ethyleneglycol-hexadecylamine (PHEA-mPEG-C16 conjugated with 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid-gadolinium (DOTA-Gd via ethylenediamine (ED was synthesized as a magnetic resonance imaging (MRI contrast agent. Amphiphilic PHEA-mPEG-C16-ED-DOTA-Gd forms micelle in aqueous solution. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR. Micelle size and shape were examined by dynamic light scattering (DLS and atomic force microscopy (AFM. Micelles with PHEA-mPEG-C16-ED-DOTA-Gd showed higher relaxivities than the commercially available gadolinium contrast agent. Moreover, the signal intensity of a rabbit liver was effectively increased after intravenous injection of PHEA-mPEG-C16-ED-DOTA-Gd.

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

    Science.gov (United States)

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

    2011-08-01

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

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

    Science.gov (United States)

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

    2013-11-15

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

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Modulation of physical and biological properties of a composite PLLA and polyaspartamide derivative obtained via thermally induced phase separation (TIPS) technique

    Energy Technology Data Exchange (ETDEWEB)

    Carfì Pavia, Francesco [Department of Civil, Environmental, Aerospace, Materials Engineering, University of Palermo, 90142 Palermo (Italy); Palumbo, Fabio Salvatore, E-mail: fabiosalvatore.palumbo@unipa.it [Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Sezione di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo (Italy); La Carrubba, Vincenzo [Department of Civil, Environmental, Aerospace, Materials Engineering, University of Palermo, 90142 Palermo (Italy); Istituto Euro Mediterraneo di Scienza e Tecnologia (IEMEST) Via Michele Miraglia, 20 - 90139, Palermo (Italy); Bongiovì, Flavia [Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Sezione di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo (Italy); Brucato, Valerio [Department of Civil, Environmental, Aerospace, Materials Engineering, University of Palermo, 90142 Palermo (Italy); Pitarresi, Giovanna; Giammona, Gaetano [Dipartimento di Scienze e Tecnologie Biologiche Chimiche e Farmaceutiche, Sezione di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo (Italy)

    2016-10-01

    In the present study, blend of poly L-lactic acid (PLLA) with a graft copolymer based on α,β-poly(N-hydroxyethyl)-DL-aspartamide and PLA named PHEA-PLA, has been used to design porous scaffold by using Thermally Induced Phase Separation (TIPS) technique. Starting from a homogeneous ternary solution of polymers, dioxane and deionised water, PLLA/PHEA-PLA porous foams have been produced by varying the polymers concentration and de-mixing temperature in metastable region. Results have shown that scaffolds prepared with a polymer concentration of 4% and de-mixing temperature of 22.5 °C are the best among those assessed, due to their optimal pore size and interconnection. SEM and DSC analysis have been carried out respectively to study scaffold morphology and the influence of PHEA-PLA on PLLA crystallization, while DMF extraction has been carried out in order to quantify PHEA-PLA into the final scaffolds. To evaluate scaffold biodegradability, a hydrolysis study has been performed until 56 days by incubating systems in a media mimicking physiological environment (pH 7.4). Results obtained have highlighted a progressive increase in weight loss with time in PLLA/PHEA-PLA scaffolds, conceivably due to the presence of PHEA-PLA and polymers interpenetration. Viability and adhesion of bovine chondrocytes seeded on the scaffolds have been studied by MTS test and SEM analysis. From results achieved it appears that the presence of PHEA-PLA increases cells affinity, allowing a faster adhesion and proliferation inside the scaffold. - Highlights: • Blended scaffolds of PLLA and PHEA-PLA were successfully obtained with TIPS technique. • Scaffolds with an open porosity and a good interconnection were formed. • PHEA-PLA improved water affinity accelerating rate of hydrolysis of blended scaffold. • Preliminary assay suggests that PHEA-PLA improved chondrocytes uptake and viability.

  20. Modulation of physical and biological properties of a composite PLLA and polyaspartamide derivative obtained via thermally induced phase separation (TIPS) technique

    International Nuclear Information System (INIS)

    Carfì Pavia, Francesco; Palumbo, Fabio Salvatore; La Carrubba, Vincenzo; Bongiovì, Flavia; Brucato, Valerio; Pitarresi, Giovanna; Giammona, Gaetano

    2016-01-01

    In the present study, blend of poly L-lactic acid (PLLA) with a graft copolymer based on α,β-poly(N-hydroxyethyl)-DL-aspartamide and PLA named PHEA-PLA, has been used to design porous scaffold by using Thermally Induced Phase Separation (TIPS) technique. Starting from a homogeneous ternary solution of polymers, dioxane and deionised water, PLLA/PHEA-PLA porous foams have been produced by varying the polymers concentration and de-mixing temperature in metastable region. Results have shown that scaffolds prepared with a polymer concentration of 4% and de-mixing temperature of 22.5 °C are the best among those assessed, due to their optimal pore size and interconnection. SEM and DSC analysis have been carried out respectively to study scaffold morphology and the influence of PHEA-PLA on PLLA crystallization, while DMF extraction has been carried out in order to quantify PHEA-PLA into the final scaffolds. To evaluate scaffold biodegradability, a hydrolysis study has been performed until 56 days by incubating systems in a media mimicking physiological environment (pH 7.4). Results obtained have highlighted a progressive increase in weight loss with time in PLLA/PHEA-PLA scaffolds, conceivably due to the presence of PHEA-PLA and polymers interpenetration. Viability and adhesion of bovine chondrocytes seeded on the scaffolds have been studied by MTS test and SEM analysis. From results achieved it appears that the presence of PHEA-PLA increases cells affinity, allowing a faster adhesion and proliferation inside the scaffold. - Highlights: • Blended scaffolds of PLLA and PHEA-PLA were successfully obtained with TIPS technique. • Scaffolds with an open porosity and a good interconnection were formed. • PHEA-PLA improved water affinity accelerating rate of hydrolysis of blended scaffold. • Preliminary assay suggests that PHEA-PLA improved chondrocytes uptake and viability.

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

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    Khadijah Ahmadi

    2014-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Renata Souto

    2014-06-01

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

  3. Extrahuman Epidemiology of Acinetobacter baumannii in Lebanon

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2018-05-12

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

  5. Copper Resistance of the Emerging Pathogen Acinetobacter baumannii

    Science.gov (United States)

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

    2016-01-01

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

  6. Copper Resistance of the Emerging Pathogen Acinetobacter baumannii.

    Science.gov (United States)

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

    2016-10-15

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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Characterization and degradation potential of diesel-degrading bacterial strains for application in bioremediation.

    Science.gov (United States)

    Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Van Hamme, Jonathan; Weyens, Nele; Monterroso, Carmen; Vangronsveld, Jaco

    2017-10-03

    Bioremediation of polluted soils is a promising technique with low environmental impact, which uses soil organisms to degrade soil contaminants. In this study, 19 bacterial strains isolated from a diesel-contaminated soil were screened for their diesel-degrading potential, biosurfactant (BS) production, and biofilm formation abilities, all desirable characteristics when selecting strains for re-inoculation into hydrocarbon-contaminated soils. Diesel-degradation rates were determined in vitro in minimal medium with diesel as the sole carbon source. The capacity to degrade diesel range organics (DROs) of strains SPG23 (Arthobacter sp.) and PF1 (Acinetobacter oleivorans) reached 17-26% of total DROs after 10 days, and 90% for strain GK2 (Acinetobacter calcoaceticus). The amount and rate of alkane degradation decreased significantly with increasing carbon number for strains SPG23 and PF1. Strain GK2, which produced BSs and biofilms, exhibited a greater extent, and faster rate of alkane degradation compared to SPG23 and PF1. Based on the outcomes of degradation experiments, in addition to BS production, biofilm formation capacities, and previous genome characterizations, strain GK2 is a promising candidate for microbial-assisted phytoremediation of diesel-contaminated soils. These results are of particular interest to select suitable strains for bioremediation, not only presenting high diesel-degradation rates, but also other characteristics which could improve rhizosphere colonization.

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

    Science.gov (United States)

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

    2014-01-01

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

  10. KatG and KatE Confer Acinetobacter Resistance to Hydrogen Peroxide but Sensitize Bacteria to Killing by Phagocytic Respiratory Burst

    Science.gov (United States)

    Sun, Daqing; Crowell, Sara A.; Harding, Christian M.; De Silva, P. Malaka; Harrison, Alistair; Fernando, Dinesh M.; Mason, Kevin M.; Santana, Estevan; Loewen, Peter C.; Kumar, Ayush; Liu, Yusen

    2016-01-01

    Aims Catalase catalyzes the degradation of H2O2. Acinetobacter species have four predicted catalase genes, katA, katE, katG, and katX. The aims of the present study seek to determine which catalase(s) plays a predominant role in determining the resistance to H2O2, and to assess the role of catalase in Acinetobacter virulence. Main Methods Mutants of A. baumannii and A. nosocomialis with deficiencies in katA, katE, katG, and katX were tested for sensitivity to H2O2, either by halo assays or by liquid culture assays. Respiratory burst of neutrophils, in response to A. nosocomialis, was assessed by chemiluminescence to examine the effects of catalase on the production of reactive oxygen species (ROS)1 in neutrophils. Bacterial virulence was assessed using a Galleria mellonella larva infection model. Key findings The capacities of A. baumannii and A. nosocomialis to degrade H2O2 are largely dependent on katE. The resistance of both A. baumannii and A. nosocomialis to H2O2 is primarily determined by the katG gene, although katE also plays a minor role in H2O2 resistance. Bacteria lacking both the katG and katE genes exhibit the highest sensitivity to H2O2. While A. nosocomialis bacteria with katE and/or katG were able to decrease ROS production by neutrophils, these cells also induced a more robust respiratory burst in neutrophils than did cells deficient in both katE and katG. We also found that A. nosocomialis deficient in both katE and katG was more virulent than the wildtype A. nosocomialis strain. Significance Our findings suggest that inhibition of Acinetobacter catalase may help to overcome the resistance of Acinetobacter species to microbicidal H2O2 and facilitate bacterial disinfection. PMID:26860891

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

    Science.gov (United States)

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

    2012-09-01

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

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

    OpenAIRE

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2006-12-15

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

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

    Science.gov (United States)

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

    2017-07-01

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

  17. Pneumonia adquirida na comunidade numa criança saudável por Acinetobacter

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    G. Moreira Silva

    2012-03-01

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

  18. Acinetobacter species in the hospital environment : tracing and epidemiology.

    NARCIS (Netherlands)

    L. Dijkshoorn-de Bruin (Lenie)

    1990-01-01

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

  19. Endophthalmitis caused by Acinetobacter baumanni: a case series.

    Science.gov (United States)

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

    2013-03-01

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

  20. Biodegradation of Medium Chain Hydrocarbons by Acinetobacter venetianus 2AW Immobilized to Hair-Based Adsorbent Mats (Postprint)

    Science.gov (United States)

    2010-09-01

    open- water oil spills or treatment of large contaminated volumes such as ballast water or holding ponds. The practi- cal application of the mat is...SS, Al-Hasan RH, Salamah S, Al-Dabbous A. Biore- mediation of oily sea water by bacteria immobilized in biofilms coating macroalgae . Int Biodeter...adsorbent, for in situ degradation of hydrocarbons, has practical application in the bioremediation of oil in water emulsions. acinetobacter

  1. Bloodstream infection caused by extensively drug-resistant Acinetobacter baumannii in cancer patients: high mortality associated with delayed treatment rather than with the degree of neutropenia.

    Science.gov (United States)

    Freire, M P; de Oliveira Garcia, D; Garcia, C P; Campagnari Bueno, M F; Camargo, C H; Kono Magri, A S G; Francisco, G R; Reghini, R; Vieira, M F; Ibrahim, K Y; Rossi, F; Hajjar, L; Levin, A S; Hoff, P M; Pierrotti, L C; Abdala, E

    2016-04-01

    This study aimed to describe severe infections with extensively drug-resistant Acinetobacter baumannii-calcoaceticus complex (XDR-ABC), as well as to investigate risk factors for mortality, in cancer patients. It was a retrospective study including all patients diagnosed with XDR-ABC bacteraemia during hospitalization in the intensive care unit of a cancer hospital between July 2009 and July 2013. Surveillance cultures were collected weekly during the study period, and clonality was analysed using pulsed field gel electrophoresis (PFGE). We analysed underlying diseases, oncology therapy, neutrophil counts, infection site and management of infection, in terms of their correlation with 30-day mortality. During the study period, 92 patients with XDR-ABC bacteraemia were identified, of whom 35 (38.0%) were patients with haematological malignancy. We identified XDR-ABC strains with four different profile patterns, 91.3% of patients harbouring the predominant PFGE type. Of the 92 patients with XDR-ABC bacteraemia, 66 (71.7%) had central line-associated bloodstream infections; infection occurred during neutropenia in 22 (23.9%); and 58 (63.0%) died before receiving the appropriate therapy. All patients were treated with polymyxin, which was used in combination therapy in 30 of them (32.4%). The 30-day mortality rate was 83.7%. Multivariate analysis revealed that septic shock at diagnosis of XDR-ABC infection was a risk factor for 30-day mortality; protective factors were receiving appropriate therapy and invasive device removal within the first 48 h. Among cancer patients, ineffective management of such infection increases the risk of death, more so than do features such as neutropenia and infection at the tumour site. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2014-10-13

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

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

    African Journals Online (AJOL)

    S. Natoubi

    2016-11-18

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

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

    Science.gov (United States)

    Kim, Dae Hun; Ko, Kwan Soo

    2015-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Wadhwani SA

    2017-09-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  7. Ability of phages to infect Acinetobacter calcoaceticus-Acinetobacter baumannii complex species through acquisition of different pectate lyase depolymerase domains

    NARCIS (Netherlands)

    Oliveira, Hugo; Costa, Ana R.; Konstantinides, Nico; Ferreira, Alice; Akturk, Ergun; Sillankorva, Sanna; Nemec, Alexandr; Shneider, Mikhail; Dötsch, Andreas; Azeredo, Joana

    2017-01-01

    Bacteriophages are ubiquitous in nature and represent a vast repository of genetic diversity, which is driven by the endless coevolution cycle with a diversified group of bacterial hosts. Studying phage-host interactions is important to gain novel insights into their dynamic adaptation. In this

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Li, Xiuyuan; Tang, Yanyan; Lu, Xinxin

    2018-04-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Monjuri Kataki

    2017-02-01

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

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

    OpenAIRE

    Yesim Cekin

    2014-01-01

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

  13. 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

    Directory of Open Access Journals (Sweden)

    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.

  14. Characterization of Acinetobacter baumannii strain PS3 in degradation of food emulsifiers

    Science.gov (United States)

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

    2018-04-01

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

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

    Science.gov (United States)

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

    2016-03-08

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

  16. An Increase of Abundance and Transcriptional Activity for Acinetobacter junii Post Wastewater Treatment

    Directory of Open Access Journals (Sweden)

    Muhammad Raihan Jumat

    2018-04-01

    Full Text Available A membrane bioreactor (MBR-based wastewater treatment plant (WWTP in Saudi Arabia is assessed over a five-month period in 2015 and once in 2017 for bacterial diversity and transcriptional activity using metagenomics, metatranscriptomics and real time quantitative polymerase chain reaction (RT-qPCR. Acinetobacter spp. are shown to be enriched in the chlorinated effluent. Members of the Acinetobacter genus are the most abundant in the effluent and chlorinated effluent. At the species level, Acinetobacter junii have higher relative abundances post MBR and chlorination. RNA-seq analysis show that, in A. junii, 288 genes and 378 genes are significantly upregulated in the effluent and chlorinated effluent, respectively, with 98 genes being upregulated in both. RT-qPCR of samples in 2015 and 2017 confirm the upregulation observed in RNA-seq. Analysis of the 98 genes show that majority of the upregulated genes are involved in cellular repair and metabolism followed by resistance, virulence, and signaling. Additionally, two different subpopulations of A. junii are observed in the effluent and chlorinated effluent. The upregulation of cellular repair and metabolism genes, and the formation of different subpopulations of A. junii in both effluents provide insights into the mechanisms employed by A. junii to persist in the conditions of a WWTP.

  17. An Increase of Abundance and Transcriptional Activity for Acinetobacter junii Post Wastewater Treatment

    KAUST Repository

    Jumat, Muhammad; Haroon, Muhammad; Aljassim, Nada I.; Cheng, Hong; Hong, Pei-Ying

    2018-01-01

    A membrane bioreactor (MBR)-based wastewater treatment plant (WWTP) in Saudi Arabia is assessed over a five-month period in 2015 and once in 2017 for bacterial diversity and transcriptional activity using metagenomics, metatranscriptomics and real time quantitative polymerase chain reaction (RT-qPCR). Acinetobacter spp. are shown to be enriched in the chlorinated effluent. Members of the Acinetobacter genus are the most abundant in the effluent and chlorinated effluent. At the species level, Acinetobacter junii have higher relative abundances post MBR and chlorination. RNA-seq analysis show that, in A. junii, 288 genes and 378 genes are significantly upregulated in the effluent and chlorinated effluent, respectively, with 98 genes being upregulated in both. RT-qPCR of samples in 2015 and 2017 confirm the upregulation observed in RNA-seq. Analysis of the 98 genes show that majority of the upregulated genes are involved in cellular repair and metabolism followed by resistance, virulence, and signaling. Additionally, two different subpopulations of A. junii are observed in the effluent and chlorinated effluent. The upregulation of cellular repair and metabolism genes, and the formation of different subpopulations of A. junii in both effluents provide insights into the mechanisms employed by A. junii to persist in the conditions of a WWTP.

  18. An Increase of Abundance and Transcriptional Activity for Acinetobacter junii Post Wastewater Treatment

    KAUST Repository

    Jumat, Muhammad

    2018-04-11

    A membrane bioreactor (MBR)-based wastewater treatment plant (WWTP) in Saudi Arabia is assessed over a five-month period in 2015 and once in 2017 for bacterial diversity and transcriptional activity using metagenomics, metatranscriptomics and real time quantitative polymerase chain reaction (RT-qPCR). Acinetobacter spp. are shown to be enriched in the chlorinated effluent. Members of the Acinetobacter genus are the most abundant in the effluent and chlorinated effluent. At the species level, Acinetobacter junii have higher relative abundances post MBR and chlorination. RNA-seq analysis show that, in A. junii, 288 genes and 378 genes are significantly upregulated in the effluent and chlorinated effluent, respectively, with 98 genes being upregulated in both. RT-qPCR of samples in 2015 and 2017 confirm the upregulation observed in RNA-seq. Analysis of the 98 genes show that majority of the upregulated genes are involved in cellular repair and metabolism followed by resistance, virulence, and signaling. Additionally, two different subpopulations of A. junii are observed in the effluent and chlorinated effluent. The upregulation of cellular repair and metabolism genes, and the formation of different subpopulations of A. junii in both effluents provide insights into the mechanisms employed by A. junii to persist in the conditions of a WWTP.

  19. Isolation, molecular and biochemical characterization of oil degrading bacteria from contaminated soil at an oil refinery

    International Nuclear Information System (INIS)

    AL-Deeb, T.M.; Malkawi, H.I.

    2009-01-01

    Biodegradation using microorganisms is considered to be cost-effective and environmentally friendly treatment of oil-contaminated sites. Oil-biodegrading bacterial strains were isolated, identified and characterized from oil contaminated soil samples at oil refinery in Zarqa (Jordan). Thirty four bacterial isolates were grown on mineral salt media supplemented with crude oil, but 16 showed positive biodegradation of diesel. All the 34 bacterial isolates were characterized at the molecular and bio-chemical levels, and showed positive polymerase chain reaction (PCR) amplification product size of 1500 bp when 16s rDNA bacterial universal primers were used. Eighteen bacterial isolates showed positive PCR amplification product size of 150 bp specific for the genus Pseudomonas and 3 bacterial isolates showed positive amplification product size of 1500 bp specific for the genus Acinetobacter. Biochemical and physiological characterization performed on the 34 bacterial isolates revealed the presence of oil biodegrading bacterial genera and species of Pseudomonas Acidovorans, P. aeruginosa, P. vesicularis, Acinetobacter calcoaceticus, Ac. lowffii, Micro-ococcus luteus, M. varians, M. lylae, M. roseus, Alcaligenes denitrificians, Bacillus megaterium, Comamonas sp., Moralxella sp., Bordetella sp., P. putida, P. stutzeri and P. mallei. (au)

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

    Science.gov (United States)

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

    2018-03-01

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

  1. Insight on specificity of uracil permeases of the NAT/NCS2 family from analysis of the transporter encoded in the pyrimidine utilization operon of Escherichia coli.

    Science.gov (United States)

    Botou, Maria; Lazou, Panayiota; Papakostas, Konstantinos; Lambrinidis, George; Evangelidis, Thomas; Mikros, Emmanuel; Frillingos, Stathis

    2018-04-01

    The uracil permease UraA of Escherichia coli is a structurally known prototype for the ubiquitous Nucleobase-Ascorbate Transporter (NAT) or Nucleobase-Cation Symporter-2 (NCS2) family and represents a well-defined subgroup of bacterial homologs that remain functionally unstudied. Here, we analyze four of these homologs, including RutG of E. coli which shares 35% identity with UraA and is encoded in the catabolic rut (pyrimidine utilization) operon. Using amplified expression in E. coli K-12, we show that RutG is a high-affinity permease for uracil, thymine and, at low efficiency, xanthine and recognizes also 5-fluorouracil and oxypurinol. In contrast, UraA and the homologs from Acinetobacter calcoaceticus and Aeromonas veronii are permeases specific for uracil and 5-fluorouracil. Molecular docking indicates that thymine is hindered from binding to UraA by a highly conserved Phe residue which is absent in RutG. Site-directed replacement of this Phe with Ala in the three uracil-specific homologs allows high-affinity recognition and/or transport of thymine, emulating the RutG profile. Furthermore, all RutG orthologs from enterobacteria retain an Ala at this position, implying that they can use both uracil and thymine and, possibly, xanthine as substrates and provide the bacterial cell with a range of catabolizable nucleobases. © 2018 John Wiley & Sons Ltd.

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

    OpenAIRE

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

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Keramettin Yanik

    2015-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Anthony J Brzoska

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

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

    Science.gov (United States)

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

    2016-11-01

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

  6. Simultaneous enhancement of phenolic compound degradations by Acinetobacter strain V2 via a step-wise continuous acclimation process.

    Science.gov (United States)

    Lin, Johnson; Sharma, Vikas; Milase, Ridwaan; Mbhense, Ntuthuko

    2016-06-01

    Phenol degradation enhancement of Acinetobacter strain V2 by a step-wise continuous acclimation process was investigated. At the end of 8 months, three stable adapted strains, designated as R, G, and Y, were developed with the sub-lethal concentration of phenol at 800, 1100, and 1400 mg/L, respectively, from 400 mg/L of V2 parent strain. All strains degraded phenol at their sub-lethal level within 24 h, their growth rate increased as the acclimation process continued and retained their degradation properties even after storing at -80 °C for more than 3 years. All adapted strains appeared coccoid with an ungranulated surface under electron microscope compared to typical rod-shaped parental strain V2 . The adapted Y strain also possessed superior degradation ability against aniline, benzoate, and toluene. This study demonstrated the use of long term acclimation process to develop efficient and better pollutant degrading bacterial strains with potentials in industrial and environmental bioremediation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

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

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

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    Pablo Vitoriano Cirino

    2008-08-01

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

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

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    Yiqi Fu

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

  10. Purification, biochemical characterization, and implications of an alkali-tolerant catalase from the spacecraft-associated and oxidation-resistant Acinetobacter gyllenbergii 2P01AA.

    Science.gov (United States)

    Muster, N; Derecho, I; Dallal, F; Alvarez, R; McCoy, K B; Mogul, R

    2015-04-01

    Herein, we report on the purification, characterization, and sequencing of catalase from Acinetobacter gyllenbergii 2P01AA, an extremely oxidation-resistant bacterium that was isolated from the Mars Phoenix spacecraft assembly facility. The Acinetobacter are dominant members of the microbial communities that inhabit spacecraft assembly facilities and consequently may serve as forward contaminants that could impact the integrity of future life-detection missions. Catalase was purified by using a 3-step chromatographic procedure, where mass spectrometry provided respective subunit and intact masses of 57.8 and 234.6 kDa, which were consistent with a small-subunit tetrameric catalase. Kinetics revealed an extreme pH stability with no loss in activity between pH 5 and 11.5 and provided respective kcat/Km and kcat values of ∼10(7) s(-1) M(-1) and 10(6) s(-1), which are among the highest reported for bacterial catalases. The amino acid sequence was deduced by in-depth peptide mapping, and structural homology suggested that the catalases from differing strains of A. gyllenbergii differ only at residues near the subunit interfaces, which may impact catalytic stability. Together, the kinetic, alkali-tolerant, and halotolerant properties of the catalase from A. gyllenbergii 2P01AA are significant, as they are consistent with molecular adaptations toward the alkaline, low-humidity, and potentially oxidizing conditions of spacecraft assembly facilities. Therefore, these results support the hypothesis that the selective pressures of the assembly facilities impact the microbial communities at the molecular level, which may have broad implications for future life-detection missions.

  11. Colistin-Resistant Acinetobacter baumannii Clinical Strains with Deficient Biofilm Formation

    Science.gov (United States)

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

    2015-01-01

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

  12. Spread of carbapenem-resistant Acinetobacter baumannii global clone 2 in Asia and AbaR-type resistance islands.

    Science.gov (United States)

    Kim, Dae Hun; Choi, Ji-Young; Kim, Hae Won; Kim, So Hyun; Chung, Doo Ryeon; Peck, Kyong Ran; Thamlikitkul, Visanu; So, Thomas Man-Kit; Yasin, Rohani M D; Hsueh, Po-Ren; Carlos, Celia C; Hsu, Li Yang; Buntaran, Latre; Lalitha, M K; Song, Jae-Hoon; Ko, Kwan Soo

    2013-11-01

    In this surveillance study, we identified the genotypes, carbapenem resistance determinants, and structural variations of AbaR-type resistance islands among carbapenem-resistant Acinetobacter baumannii (CRAB) isolates from nine Asian locales. Clonal complex 92 (CC92), corresponding to global clone 2 (GC2), was the most prevalent in most Asian locales (83/108 isolates; 76.9%). CC108, or GC1, was a predominant clone in India. OXA-23 oxacillinase was detected in CRAB isolates from most Asian locales except Taiwan. blaOXA-24 was found in CRAB isolates from Taiwan. AbaR4-type resistance islands, which were divided into six subtypes, were identified in most CRAB isolates investigated. Five isolates from India, Malaysia, Singapore, and Hong Kong contained AbaR3-type resistance islands. Of these, three isolates harbored both AbaR3- and AbaR4-type resistance islands simultaneously. In this study, GC2 was revealed as a prevalent clone in most Asian locales, with the AbaR4-type resistance island predominant, with diverse variants. The significance of this study lies in identifying the spread of global clones of carbapenem-resistant A. baumannii in Asia.

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

    Science.gov (United States)

    Perez, Leandro Reus Rodrigues

    2015-02-01

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

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

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    Bandana Baniya

    2017-11-01

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

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

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    Lul Raka

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

  16. Osmotic Compounds Enhance Antibiotic Efficacy against Acinetobacter baumannii Biofilm Communities.

    Science.gov (United States)

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

    2017-10-01

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

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

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    Luján Roca DA

    2013-01-01

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

  18. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2016-12-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

  1. Genetic Regulation of Virulence and Antibiotic Resistance in Acinetobacter baumannii

    Science.gov (United States)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-12-01

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

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

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    Neda Farahani

    2013-03-01

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

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

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    Simit H Kumar

    2012-01-01

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

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

    Science.gov (United States)

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

    2010-09-01

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

  7. Insertions in the OCL1 locus of Acinetobacter baumannii lead to shortened lipooligosaccharides

    Science.gov (United States)

    Kenyon, Johanna J.; Holt, Kathryn E.; Pickard, Derek; Dougan, Gordon; Hall, Ruth M.

    2014-01-01

    Genomes of 82 Acinetobacter baumannii global clones 1 (GC1) and 2 (GC2) isolates were sequenced and different forms of the locus predicted to direct synthesis of the outer core (OC) of the lipooligosaccharide were identified. OCL1 was in all GC2 genomes, whereas GC1 isolates carried OCL1, OCL3 or a new locus, OCL5. Three mutants in which an insertion sequence (ISAba1 or ISAba23) interrupted OCL1 were identified. Isolates with OCL1 intact produced only lipooligosaccharide, while the mutants produced lipooligosaccharide of reduced molecular weight. Thus, the assignment of the OC locus as that responsible for the synthesis of the OC is correct. PMID:24861001

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

    NARCIS (Netherlands)

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

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

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

    NARCIS (Netherlands)

    Breij, Anastasia (Anna)

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Johanna J Kenyon

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

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

    Directory of Open Access Journals (Sweden)

    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

  12. Identification of Opportunistic Pathogenic Bacteria in Drinking Water Samples of Different Rural Health Centers and Their Clinical Impacts on Humans

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    Pavan Kumar Pindi

    2013-01-01

    Full Text Available International drinking water quality monitoring programs have been established in order to prevent or to reduce the risk of contracting water-related infections. A survey was performed on groundwater-derived drinking water from 13 different hospitals in the Mahabubnagar District. A total of 55 bacterial strains were isolated which belonged to both gram-positive and gram-negative bacteria. All the taxa were identified based on the 16S rRNA gene sequence analysis based on which they are phylogenetically close to 27 different taxa. Many of the strains are closely related to their phylogenetic neighbors and exhibit from 98.4 to 100% sequence similarity at the 16S rRNA gene sequence level. The most common group was similar to Acinetobacter junii (21.8% and Acinetobacter calcoaceticus (10.9% which were shared by 7 and 5 water samples, respectively. Out of 55 isolates, only 3 isolates belonged to coliform group which are Citrobacter freundii and Pantoea anthophila. More than half (52.7%, 29 strains of the phylogenetic neighbors which belonged to 12 groups were reported to be pathogenic and isolated from clinical specimens. Out of 27 representative taxa are affiliated have eight representative genera in drinking water except for those affiliated with the genera Exiguobacterium, Delftia, Kocuria, and Lysinibacillus.

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

    NARCIS (Netherlands)

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

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  15. Oral flora of Python regius kept as pets.

    Science.gov (United States)

    Dipineto, L; Russo, T P; Calabria, M; De Rosa, L; Capasso, M; Menna, L F; Borrelli, L; Fioretti, A

    2014-05-01

    This study was aimed at evaluating the oral bacterial flora of 60 Python regius kept as pets by culture and biochemical methods. All isolates were also submitted to antimicrobial susceptibility testing using the disc diffusion method. The oral cavity of snakes sampled harboured a wide range of Gram-negative bacteria mainly constituted by Pseudomonas spp., Morganella morganii, Acinetobacter calcoaceticus, Aeromonas hydrophila, but also by Salmonella spp. Staphylococcus spp. was the commonest Gram-positive isolates, and various anaerobic Clostridium species were also found. The most effective antimicrobial agents were enrofloxacin and ciprofloxacin, followed by doxycycline and gentamicin. The oral cavity of snakes sampled harboured a wide range of bacteria. Our results suggest that people who come in contact with snakes could be at risk of infection and should follow proper hygiene practices when handling these reptiles. © 2014 The Society for Applied Microbiology.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Faegheh Teymori

    2017-07-01

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

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

    Science.gov (United States)

    2015-07-20

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

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

    KAUST Repository

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

    2017-01-01

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

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

    KAUST Repository

    Lafi, Feras Fawzi

    2017-03-03

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

  1. High prevalence of extensively drug-resistant and metallo beta-lactamase-producing clinical Acinetobacter baumannii in Iran.

    Science.gov (United States)

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

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    Hai Kuan Wang

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickx, L

    2002-07-01

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

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

    Science.gov (United States)

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

    2014-01-01

    The aim of this study was to evaluate the effect of proteolytic (Serratia liquefaciens, match %: 99.39) or lipolytic (Acinetobacter genomospecies 10, match %: 99.90) psychrotrophic bacteria (bacterial counts, analysis of free fatty acids (FFA) and analysis of free amino acids) on the microbial and chemical properties (yogurt composition), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of yogurt during storage. Yogurts were prepared with raw milk preinoculated with each psychrotrophic bacteria. The total solid, fat, and protein content were not affected by preinoculation, but the pH of yogurt preinoculated with psychrotrophic bacteria was higher than in control. There was a dramatic increase in short chain free fatty acids among FFA in yogurt with Acinetobacter genomospecies 10. For 14 d of cold storage condition, SCFFA was 25.3 mg/kg to 34.4 mg/kg (1.36 times increased), MCFFA was 20.4 mg/kg to 25.7 mg/kg (1.26 times increased), and LCFFA was 240.2 mg/kg to 322.8 mg/kg (1.34 times increased). Serratia liquefaciens (match %: 99.39) in yogurt caused a greater accumulation of free amino acids (FAA), especially bitter peptides such as leucine, valine, arginine, and tyrosine, but SDS-PAGE showed that the inoculation of Serratia liquefaciens did not affect the degree of casein degradation during storage. Taken together, the excessive peptides and FFA in yogurt generated from psychrotrophic bacteria could develop off-flavors that degrade the quality of commercial yogurt products. PMID:26761293

  5. ISAba1 Regulated OXA-23 Carbapenem Resistance in Acinetobacter baumannii Strains in Durban, South Africa.

    Science.gov (United States)

    Agoba, Esther Eyram; Govinden, Usha; Peer, Abdool Kader Cassim; Osei Sekyere, John; Essack, Sabiha Yusuf

    2018-03-20

    This study investigated the molecular mechanisms of resistance to carbapenems and cephalosporins in 24 consecutive, multidrug-resistant Acinetobacter baumannii (MDRAB) isolates collected between January and April 2015 by a private sector laboratory in Durban, South Africa. All isolates were resistant to all carbapenems tested. bla OXA-23 and bla OXA-51 genes were found in 23 isolates, while bla OXA-24 , bla OXA-48 , and bla OXA-58 were absent in all isolates. The most prevalent extended-spectrum β-lactamase was TEM-116 (92%). bla ADC was present in 83.3% of isolates, of which two were new variants with three and five amino acid differences compared to Acinetobacter-derived cephalosporinase (ADC)-1, the first at positions 64E → K, 341N → T, and 342R → G and the second at positions 24G → D, 167S → P, 283R → F, 341N → T, and 342R → G, respectively. All isolates were negative for bla PER , bla CMY , bla GES , bla KPC , bla CTX-M , and bla SHV . Metallo-β-lactamase IMP and VIM were absent in all isolates, and NDM-1 was present in 1 isolate. ISAba1 was located upstream bla OXA-23 in all isolates and upstream bla ADC (30, 78, 79, 87 and the ADC variants) in 54.2% of the ADC-carrying isolates. None of the isolates had ISAba1 inserted upstream bla OXA-51 gene. Four isolates were clonally related and showed two clusters (A and B), while 20 isolates remained unclustered. There was no direct relationship between the clusters and the hospitals they were isolated from. This study reports the first NDM-1-producing carbapenem resistant Acinetobacter baumannii isolate in South Africa and highlights the presence of OXA-23, the known ADCs (ADC-30, ADC-78, ADC-79, and ADC-87), and two new ADC variants associated with ISAba1 from the private health sector in Durban, South Africa. The complexity and diversity of MDRAB severely limit treatment options.

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

    Science.gov (United States)

    2017-06-01

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

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

    Science.gov (United States)

    Subramaniyan, Jayanthi Siva; Sundaram, Jeya Meenakshi

    2018-01-01

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

  8. Successfull Treatment of Ventriculitis Caused by Extensively Drug Resistant (XDR Acinetobacter Baumannii with Intraventriculer Colistin Administration: Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Gokhan Karaahmetoglu

    2014-08-01

    Full Text Available Acinetobacter baumanni is an important nosocomial infection pathogen has emerged worldwide and can causes life-threatening hospital acquired infections, particularly in intensive care units (ICU. After post neurosurgical operations or procedures, this pathogen consists with central nervous system (CNS infections, also. Resistance mechanism of these pathogens against broad-spectrum antimicrobials is the challenging problem and limited penetration of antibiotics to achieve therapeutic concentrations in cerebrospinal fluid (CSF has been still controversial issue. Here we report two cases who had ventriculitis after external ventricular drainage (EVD placement procedures. Both of CSF of two cases yielded XDR (Extensively drug resistant Acinetobacter baumanni. Traditional intravenous treatment did not eradicate pathogen exactly, at first. Adjunctive colistimetat sodium every 12 h (10 mg/kg/day by the route of intraventriculer (IVT was admitted and CSF sterilization was achieved thereafter. The option of IVT colistin administration must be considered with IV antibiotherapy to provide satisfactory treatment of those complicated CNS infections. [Dis Mol Med 2014; 2(4.000: 65-69

  9. Effect of Chlorine Exposure on the Survival and Antibiotic Gene Expression of Multidrug Resistant Acinetobacter baumannii in Water

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    Deepti Prasad Karumathil

    2014-02-01

    Full Text Available Acinetobacter baumannii is a multidrug resistant pathogen capable of causing a wide spectrum of clinical conditions in humans. Acinetobacter spp. is ubiquitously found in different water sources. Chlorine being the most commonly used disinfectant in water, the study investigated the effect of chlorine on the survival of A. baumannii in water and transcription of genes conferring antibiotic resistance. Eight clinical isolates of A. baumannii, including a fatal meningitis isolate (ATCC 17978 (~108 CFU/mL were separately exposed to free chlorine concentrations (0.2, 1, 2, 3 and 4 ppm with a contact time of 30, 60, 90 and 120 second. The surviving pathogen counts at each specified contact time were determined using broth dilution assay. In addition, real-time quantitative PCR (RT-qPCR analysis of the antibiotic resistance genes (efflux pump genes and those encoding resistance to specific antibiotics of three selected A. baumannii strains following exposure to chlorine was performed. Results revealed that all eight A. baumannii isolates survived the tested chlorine levels during all exposure times (p > 0.05. Additionally, there was an up-regulation of all or some of the antibiotic resistance genes in A. baumannii, indicating a chlorine-associated induction of antibiotic resistance in the pathogen.

  10. Ceftriaxone and ciprofloxacin restriction in an intensive care unit: less incidence of Acinetobacter spp. and improved susceptibility of Pseudomonas aeruginosa Restricción del uso de ceftriaxona y ciprofloxacino en una unidad de cuidados intensivos: menor incidencia de Acinetobacter spp. y mayor sensibilidad de Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Julio César Medina Presentado

    2011-12-01

    Full Text Available OBJETIVO: To determine whether restricting the use of ceftriaxone and ciprofloxacin couldsignificantly reduce colonization and infection with resistant Gram-negative bacilli (r-GNB. METHODS: A two-phase prospective study (before/after design was conducted in an intensive care unit in two time periods (2004-2006. During phase 1, there was no antibiotic restriction. During phase 2, use of ceftriaxone or ciprofloxacin was restricted. RESULTS: Atotal of 200 patients were prospectively evaluated. In phase 2, the use of ceftriaxone was reduced by 93.6% (P = 0.0001 and that of ciprofloxacin by 65.1% (P = 0.041, accompanied by a 113.8% increase in use of ampicillin-sulbactam (P = 0.002.During phase 1, 48 GNB were isolated [37 r-GNB (77.1% and 11 non-r-GNB (22.9%], compared with a total of 64 during phase 2 [27 r-GNB (42.2% and 37 non-r-GNB (57.8%](P = 0.0002. Acinetobacter spp. was isolated 13 times during phase 1 and 3 times in phase 2 (P = 0.0018. The susceptibility of Pseudomonas aeruginosa to ciprofloxacin increased from 40.0% in phase 1 to 100.0% in phase 2 (P = 0.0108. CONCLUSIONS: Restriction of ceftriaxone and ciprofloxacin reduced colonization by Acinetobacter spp. and improved the susceptibility profile of P. aeruginosa.OBJETIVO: Determinar si la restricción del uso de ceftriaxona y ciprofloxacino reduce significativamente la colonización y la infección por bacilos gramnegativos resistentes. MÉTODOS: Se efectuó un estudio prospectivo de dos fases (diseño antes/después de la intervención en una unidad de cuidados intensivos en dos períodos sucesivos entre los años 2004 y 2006. Durante la fase 1, no hubo ninguna restricción de antibióticos. Durante la fase 2, se restringió el uso de ceftriaxona y ciprofloxacino. RESULTADOS: Se evaluó prospectivamente a 200 pacientes en total. En la fase 2, el uso de ceftriaxona se redujo en 93,6% (P = 0,0001 y el de ciprofloxacino en 65,1% (P = 0,041, lo que se acompañó de un aumento de 113,8% en

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

    Science.gov (United States)

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

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    2008-01-01

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

  13. Molecular epidemiology of multidrug-resistant Acinetobacter baumannii isolates in a university hospital in Nepal reveals the emergence of a novel epidemic clonal lineage.

    Science.gov (United States)

    Shrestha, Shovita; Tada, Tatsuya; Miyoshi-Akiyama, Tohru; Ohara, Hiroshi; Shimada, Kayo; Satou, Kazuhito; Teruya, Kuniko; Nakano, Kazuma; Shiroma, Akino; Sherchand, Jeevan Bdr; Rijal, Basista Psd; Hirano, Takashi; Kirikae, Teruo; Pokhrel, Bharat Mani

    2015-11-01

    The emergence of multidrug-resistant (MDR) Acinetobacter baumannii has become a serious medical problem worldwide. To clarify the genetic and epidemiological properties of MDR A. baumannii strains isolated from a medical setting in Nepal, 246 Acinetobacter spp. isolates obtained from different patients were screened for MDR A. baumannii by antimicrobial disk susceptibility testing. Whole genomes of the MDR A. baumannii isolates were sequenced by MiSeq™ (Illumina), and the complete genome of one isolate (IOMTU433) was sequenced by PacBio RS II. Phylogenetic trees were constructed from single nucleotide polymorphism concatemers. Multilocus sequence types were deduced and drug resistance genes were identified. Of the 246 Acinetobacter spp. isolates, 122 (49.6%) were MDR A. baumannii, with the majority being resistant to aminoglycosides, carbapenems and fluoroquinolones but not to colistin and tigecycline. These isolates harboured the 16S rRNA methylase gene armA as well as bla(NDM-1), bla(OXA-23) or bla(OXA-58). MDR A. baumannii isolates belonging to clonal complex 1 (CC1) and CC2 as well as a novel clonal complex (CC149) have spread throughout a medical setting in Nepal. The MDR isolates harboured genes encoding carbapenemases (OXA and NDM-1) and a 16S rRNA methylase (ArmA). Copyright © 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Prashant K. Parandekar

    2012-01-01

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

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

    Science.gov (United States)

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

    2015-07-01

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

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

    Science.gov (United States)

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

    2017-01-01

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

  17. High prevalence of the PER-1 gene among carbapenem-resistant Acinetobacter baumannii in Riyadh, Saudi Arabia.

    Science.gov (United States)

    Aly, M M; Abu Alsoud, N M; Elrobh, M S; Al Johani, S M; Balkhy, H H

    2016-11-01

    The prevalence of carbapenem-resistant Acinetobacter baumannii in Saudi Arabia and their resistance genetic mechanisms are yet to be identified. We studied the prevalence and genetic diversity of extended-spectrum beta-lactamase genes, particularly the PER-1 gene, among carbapenem-resistant A. baumannii strains from patients at a tertiary care hospital in Riyadh, Saudi Arabia between 2006 and 2014. Fresh subcultured samples were tested for antimicrobial susceptibility minimum inhibitory concentration (MIC). Total genomic DNA was extracted from each isolate and further used for polymerase chain reaction (PCR) genotyping, sequence-based typing (SBT) of PER-1 and OXA-51-like gene, and multilocus sequence typing (MLST) of positive isolates. Randomly selected clinical isolates (n = 100) were subjected to MLST. A total of 503 isolates were characterized as multidrug-resistant (MDR) using the MIC. Isolates were further PCR tested for bla -TEM and bla -PER-1 resistance genes (n = 503). The genotyping results showed that 68/503 (14 %) isolates were positive to bla TEM. The genotyping results of PER-1-like genes showed that 384/503 (76.3 %) were positive among MDR Acinetobacter isolates. Based on SBT, the majority of these isolates were clustered into three main groups including isolates harboring PER-1: AB11 (bla -PER-1 ), isolate AB16 (bla -PER-1 ), and, finally, the plasmid pAB154 (bla -PER-7 ). Remarkably, many isolates were concealing the PER-1 gene and harboring the TEM resistance genes as well. MLST results for selected isolates (n = 100) identified four main sequence types (STs: 2, 19, 20, and 25) and four novel isolates (ST 486-489). We report 76.3 % prevalence of the PER-1 resistance gene among Acinetobacter clinical isolates from Riyadh, Saudi Arabia. Further work is needed to explore the clinical risks and patient outcome with such resistance related to healthcare-associated infections and investigate the genetic and molecular mechanisms that confer the MDR

  18. Stopping AI-2 chatter by means of an indigenous bacterium ( Acinetobacter sp. DKY-1): A new anti-biofouling strategy in an MBR for wastewater treatment.

    Science.gov (United States)

    Lee, Kibaek; Kim, Yea-Won; Lee, Seonki; Lee, Sang Hyun; Nahm, Chang Hyun; Kwon, Hyeokpil; Park, Pyung-Kyu; Choo, Kwang-Ho; Koyuncu, Ismail; Drews, Anja; Lee, Chung-Hak; Lee, Jung-Kee

    2018-05-01

    Bacterial quorum quenching (QQ) by means of degrading signaling molecules has been applied to anti-biofouling strategy in a membrane bioreactor (MBR) for wastewater treatment. However, the target signaling molecules have been limited to N-acyl homoserine lactones participating in intra-species quorum sensing. Here, an approach to disrupt autoinducer-2 (AI-2) signaling molecules participating in inter-species quorum sensing, was pursued as a next-generation anti-biofouling strategy in an MBR for wastewater treatment. We isolated an indigenous QQ bacterium ( Acinetobacter sp. DKY-1) that can attenuate the expression of quorum sensing (QS) response through inactivation of autoinducer-2 signaling molecule, 4,5-dihydroxy-2,3-pentanedione (DPD) among four kinds of autoinducer-2 QS bacteria. DKY-1 released AI-2 QQ compound(s), which was verified to be hydrophilic with a molecular weight biofouling. This new approach, combining molecular biology with wastewater engineering, could enlarge the range of QQ-MBR for anti-biofouling and energy savings in the field of wastewater treatment.

  19. Star Polymers Reduce Islet Amyloid Polypeptide Toxicity via Accelerated Amyloid Aggregation.

    Science.gov (United States)

    Pilkington, Emily H; Lai, May; Ge, Xinwei; Stanley, William J; Wang, Bo; Wang, Miaoyi; Kakinen, Aleksandr; Sani, Marc-Antonie; Whittaker, Michael R; Gurzov, Esteban N; Ding, Feng; Quinn, John F; Davis, Thomas P; Ke, Pu Chun

    2017-12-11

    Protein aggregation into amyloid fibrils is a ubiquitous phenomenon across the spectrum of neurodegenerative disorders and type 2 diabetes. A common strategy against amyloidogenesis is to minimize the populations of toxic oligomers and protofibrils by inhibiting protein aggregation with small molecules or nanoparticles. However, melanin synthesis in nature is realized by accelerated protein fibrillation to circumvent accumulation of toxic intermediates. Accordingly, we designed and demonstrated the use of star-shaped poly(2-hydroxyethyl acrylate) (PHEA) nanostructures for promoting aggregation while ameliorating the toxicity of human islet amyloid polypeptide (IAPP), the peptide involved in glycemic control and the pathology of type 2 diabetes. The binding of PHEA elevated the β-sheet content in IAPP aggregates while rendering a new morphology of "stelliform" amyloids originating from the polymers. Atomistic molecular dynamics simulations revealed that the PHEA arms served as rodlike scaffolds for IAPP binding and subsequently accelerated IAPP aggregation by increased local peptide concentration. The tertiary structure of the star nanoparticles was found to be essential for driving the specific interactions required to impel the accelerated IAPP aggregation. This study sheds new light on the structure-toxicity relationship of IAPP and points to the potential of exploiting star polymers as a new class of therapeutic agents against amyloidogenesis.

  20. Molecular Epidemiology of Carbapenem Non-Susceptible Acinetobacter baumannii in France

    Science.gov (United States)

    Jeannot, Katy; Diancourt, Laure; Vaux, Sophie; Thouverez, Michelle; Ribeiro, Amandina; Coignard, Bruno; Courvalin, Patrice; Brisse, Sylvain

    2014-01-01

    Carbapenem-resistant Acinetobacter baumannii have emerged globally. The objective of this study was to investigate the epidemiology, clonal diversity and resistance mechanisms of imipenem non-susceptible A. baumannii isolates in France. Between December 2010 and August 2011, 132 notifications were collected, including 37 outbreaks corresponding to 242 cases (2 to 55 per cluster). Multilocus sequence typing, pulsed-field gel electrophoresis (PFGE) and characterisation of carbapenemase-encoding genes were performed on 110 non-repetitive isolates. Gene bla OXA-23 was the most frequently detected (82%), followed by bla OXA-24 (11%) and bla OXA-58 (7%). Eleven sequence types (ST) were distinguished, among which sequence types ST1, ST2 (64%), ST20, ST25, ST85 and ST107. Isolates from epidemiological clusters had the same ST and resistance genes, indicating probable transmission within centres. In contrast, PFGE types of isolates differed among centres, arguing against transmission among centers. This study provides the first epidemiological snapshot of the population of A. baumannii with reduced susceptibility to carbapenems from France, and further underlines the predominance of international clones. PMID:25517732

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2016-05-01

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

  3. Electron transfer pathways in microbial oxygen biocathodes

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    Freguia, Stefano, E-mail: stefano@kais.kyoto-u.ac.j [Bio-analytical and Physical Chemistry Laboratory, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8205 (Japan); Tsujimura, Seiya, E-mail: seiya@kais.kyoto-u.ac.j [Bio-analytical and Physical Chemistry Laboratory, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8205 (Japan); Kano, Kenji, E-mail: kkano@kais.kyoto-u.ac.j [Bio-analytical and Physical Chemistry Laboratory, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8205 (Japan)

    2010-01-01

    The ability of some bacteria to enhance the rate of cathodic oxygen reduction to water has been recently discovered, opening the way to an entirely renewable and environmentally friendly concept of biocathode. In this study we reveal that several mechanisms may induce catalytic effects by bacteria. These comprise mechanisms that are putatively beneficial to the bacteria as well as mechanisms which are merely side effects, including quinone autoxidation and direct O{sub 2} reduction by heme compounds. Here we showed that 1 muM of ACNQ is able to generate a significant catalytic wave for oxygen reduction, with onset at approximately 0 V vs. SHE. Similarly, adsorption of hemin on a carbon surface catalyses O{sub 2} reduction to H{sub 2}O{sub 2} with an onset of +0.2 V vs. SHE. To evaluate the catalytic pathways of live cells on cathodic oxygen reduction, two species of electrochemically active bacteria were selected as pure cultures, namely Acinetobacter calcoaceticus and Shewanella putrefaciens. The former appears to exploit a self-excreted redox compound with redox characteristics matching those of pyrroloquinoline quinone (PQQ) for extracellular electron transfer. The latter appears to utilise outer membrane-bound redox compounds. Interaction of quinones and cytochromes with the membrane-bound electron transfer chain is yet to be proven.

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

    NARCIS (Netherlands)

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

    2006-01-01

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

  5. [Inventory building of phages against extensively drug-resistant Acinetobacter baumannii isolated from wounds of patients with severe burn and related characteristic analysis].

    Science.gov (United States)

    Yang, Z C; Deng, L Y; Gong, Y L; Yin, S P; Jiang, B; Huang, G T; Peng, Y Z; Hu, F Q

    2016-09-20

    To build inventory of phages against extensively drug-resistant Acinetobacter Baumannii isolated from wounds of inpatients of burn ICU and analyze related characteristics. In 2014 and 2015, 131 strains of extensively drug-resistant Acinetobacter Baumannii were isolated from wounds of inpatients of burn ICU from one hospital in Chongqing. In 2015, 98 strains of extensively drug-resistant Acinetobacter Baumannii were isolated from wounds of inpatients of burn ICU from 6 hospitals in Guangdong province. Above-mentioned 229 strains were collected for conducting experiments as follows: (1) Multilocus sequence typing (MLST) of strains isolated from Chongqing and Guangdong province was analyzed. (2) Sewage co-culture method was applied for isolation of phages with above-mentioned strains and sewage from Chongqing and Guangdong province. Numbers of isolated phages and times of successful isolation and unsuccessful isolation were recorded. (3) The most prevalent subtypes of strains from Chongqing and Guangdong province in 2015 were collected, and their phages respectively underwent cross infection with all strains from Chongqing and those from Guangdong province. The lysis ability of phage was observed when phage underwent cross infection with the same subtype of strain or not the same, and the lytic ratio was calculated. (4) Fluid of phage in one type was randomly selected and equally divided into 3 parts, and its titer was determined by double dilution method. Then each part of phage fluid was subdivided into 3 small parts, which were cultured with LB fluid medium and respectively stored under the condition of -20 ℃, 4 ℃, and room temperature. After being stored for 1 month and 2 months, the titer of phage was determined for evaluating stability of phage. Data were processed with Fisher's exact test, chi-square test, and one-way analysis of variance. (1) The major type of strains from Chongqing in 2014 was ST368 (45%, 31/69), and major types of strains from Chongqing

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Chitosan as an effective inhibitor of multidrug resistant Acinetobacter baumannii.

    Science.gov (United States)

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

    2017-12-15

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

  9. COST-EFFECTIVE PRODUCTION OF THE BIO-PLASTIC POLY-β-HYDROXYBUTYRATE USING ACINETOBACTER BAUMANNII ISOLATE P39

    Directory of Open Access Journals (Sweden)

    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.

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  11. Tamoxifen-loaded polymeric micelles: preparation, physico-chemical characterization and in vitro evaluation studies.

    Science.gov (United States)

    Cavallaro, Gennara; Maniscalco, Laura; Licciardi, Mariano; Giammona, Gaetano

    2004-11-20

    Several samples of polymeric micelles, formed by amphiphilic derivatives of PHEA, obtained by grafting into polymeric backbone of PEGs and/or hexadecylamine groups (PHEA-PEG-C(16) and PHEA-C(16)) and containing different amount of Tamoxifen, were prepared. All Tamoxifen-loaded polymeric micelles showed to increase drug water solubility. TEM studies provided evidence of the formation of supramolecular core/shell architectures containing drug, in the nanoscopic range and with spherical shape. Samples with different amount of encapsulated Tamoxifen were subjected to in vitro cytotoxic studies in order to evaluate the effect of Tamoxifen micellization on cell growth inhibition. All samples of Tamoxifen-loaded polymeric micelles showed a significantly higher antiproliferative activity in comparison with free drug, probably attributable to fluidification of cellular membranes, caused by amphiphilic copolymers, that allows a higher penetration of the drug into tumoral cells. To gain preliminary information about the potential use of prepared micelles as Tamoxifen drug delivery systems, studies evaluating drug release ability of micelle systems in media mimicking biological fluids (buffer solutions at pH 7.4 and 5.5) and in human plasma were carried out. These studies, performed evaluating the amount of Tamoxifen that remains in solution as a function of time, showed that at pH 7.4, as well as in plasma, PHEA-C(16) polymeric micelles were able to release lower drug amounts than PHEA-PEG(5000)-C(16) ones, while at pH 5.5, the behavior difference between two kind of micelles was less pronounced.

  12. Comparative analysis of Acinetobacters: three genomes for three lifestyles.

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    David Vallenet

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

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

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    Karp Matti

    2011-05-01

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

  14. Altered Levels of Aroma and Volatiles by Metabolic Engineering of Shikimate Pathway Genes in Tomato Fruits

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    Vered Tzin

    2015-06-01

    Full Text Available The tomato (Solanum lycopersicum fruit is an excellent source of antioxidants, dietary fibers, minerals and vitamins and therefore has been referred to as a “functional food”. Ripe tomato fruits produce a large number of specialized metabolites including volatile organic compounds. These volatiles serve as key components of the tomato fruit flavor, participate in plant pathogen and herbivore defense, and are used to attract seed dispersers. A major class of specialized metabolites is derived from the shikimate pathway followed by aromatic amino acid biosynthesis of phenylalanine, tyrosine and tryptophan. We attempted to modify tomato fruit flavor by overexpressing key regulatory genes in the shikimate pathway. Bacterial genes encoding feedback-insensitive variants of 3-Deoxy-D-Arabino-Heptulosonate 7-Phosphate Synthase (DAHPS; AroG209-9 and bi-functional Chorismate Mutase/Prephenate Dehydratase (CM/PDT; PheA12 were expressed under the control of a fruit-specific promoter. We crossed these transgenes to generate tomato plants expressing both the AroG209 and PheA12 genes. Overexpression of the AroG209-9 gene had a dramatic effect on the overall metabolic profile of the fruit, including enhanced levels of multiple volatile and non-volatile metabolites. In contrast, the PheA12 overexpression line exhibited minor metabolic effects compared to the wild type fruit. Co-expression of both the AroG209-9 and PheA12 genes in tomato resulted overall in a similar metabolic effect to that of expressing only the AroG209-9 gene. However, the aroma ranking attributes of the tomato fruits from PheA12//AroG209-9 were unique and different from those of the lines expressing a single gene, suggesting a contribution of the PheA12 gene to the overall metabolic profile. We suggest that expression of bacterial genes encoding feedback-insensitive enzymes of the shikimate pathway in tomato fruits provides a useful metabolic engineering tool for the modification of

  15. Structural studies on New Delhi Metallo-β-lactamase (NDM-2) suggest old β-lactam, penicillin to be better antibiotic for NDM-2-harbouring Acinetobacter baumanni.

    Science.gov (United States)

    Tiwari, Vishvanath; Moganty, Rajeswari R

    2013-01-01

    Acinetobacter baumannii, a Gram-negative pathogen causes nosocomial infections including pneumonia, urinary tract and respiratory infections. Carbapenem group of β-lactam antibiotics are routinely used to treat A. baumannii including multidrug-resistant clinical strains. The emergence of New Delhi Metallo-β-lactamase (NDM-2), a new type of β-lactamase and one of the major resistant determinants in A. baumannii, opened up challenges in the treatment of resistant strains. Thus, understanding the structure-function relationship of NDM-2 with different analogues of β-lactams becomes crucial. We carried out in silico studies on the interaction of various β-lactams with NDM-2 and with OXA-24, a carbapenem hydrolyzing non-NDM type β-lactamase. The binding affinity of the β-lactams to NDM-2 was found to be in the order: ceftazidime ≈ imipenem ≈ doripenem > oxacillin > aztreonam > penicillin; however, the order of their affinity to OXA-24 was quite different: ceftazidime > aztreonam > penicillin > oxacillin > doripenem > imipenem. Further, NDM-2 in comparison to OXA-24 showed stronger interaction (less X-score) with most of the β-lactams except penicillin. This suggests higher lethality posed by clinical strains expressing NDM-2 than those without NDM-2. Weak interaction between NDM-2 and penicillin clearly points out that penicillin is perhaps better option in treating A. baumannii harbouring NDM-2. Present findings provide new insights in drug resistance at the molecular level of NDM-2 and can help in designing structure-based drugs.

  16. Clonal spread of blaOXA-72-carrying Acinetobacter baumannii sequence type 512 in Taiwan.

    Science.gov (United States)

    Kuo, Han-Yueh; Hsu, Po-Jui; Chen, Jiann-Yuan; Liao, Po-Cheng; Lu, Chia-Wei; Chen, Chang-Hua; Liou, Ming-Li

    2016-07-01

    This is the first report to show an insidious outbreak of armA- and blaOXA-72-carrying Acinetobacter baumannii sequence type 512 (ST512) at a study hospital in northern Taiwan. Multilocus sequence typing revealed that this was a ST512 clone. All of the isolates with ST512 carried a novel 12,056-bp repGR2 in combination with a repGR12-type plasmid. This plasmid, designated pAB-ML, had one copy of the blaOXA-72 gene that was flanked by XerC/XerD-like sites and conferred resistance to carbapenems. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  17. Bacteria Present in Comadia redtenbacheri Larvae (Lepidoptera: Cossidae).

    Science.gov (United States)

    Hernández-Flores, L; Llanderal-Cázares, C; Guzmán-Franco, A W; Aranda-Ocampo, S

    2015-09-01

    The external and internal culturable bacterial community present in the larvae of Comadia redtenbacheri Hammerschmidt, an edible insect, was studied. Characterization of the isolates determined the existence of 18 morphotypes and phylogenetic analysis of the 16S rRNA gene revealed the existence of Paenibacillus sp., Bacillus safensis, Pseudomonas sp., Bacillus pseudomycoides, Corynebacterium variabile, Enterococcus sp., Gordonia sp., Acinetobacter calcoaceticus, Arthrobacter sp., Micrococcus sp., and Bacillus cereus. Greater diversity of bacteria was found in those larvae obtained from vendors than in those directly taken from Agave plants in nature. Many of the larvae obtained from vendors presented signs of potential disease, and after the analysis, results showed a greater bacterial community compared with the larvae with a healthy appearance. This indicates that bacterial flora can vary in accordance with how the larvae are handled during extraction, collection, and transport. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2017-10-01

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

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

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    Elkin V Lemos

    2011-10-01

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

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

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    Venous Akhavan

    2016-09-01

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

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

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    Vishvanath Tiwari

    2017-08-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  3. Structure determination of LpxD from the lipopolysaccharide-synthesis pathway of Acinetobacter baumannii

    International Nuclear Information System (INIS)

    Badger, John; Chie-Leon, Barbara; Logan, Cheyenne; Sridhar, Vandana; Sankaran, Banumathi; Zwart, Peter H.; Nienaber, Vicki

    2012-01-01

    Crystal structures of the protein LpxD from A. baumannii were solved in apo forms that are suitable for structure-based antibacterial drug discovery. Acinetobacter baumannii is a Gram-negative bacterium that is resistant to many currently available antibiotics. The protein LpxD is a component of the biosynthetic pathway for lipopolysaccharides in the outer membrane of this bacterium and is a potential target for new antibacterial agents. This paper describes the structure determination of apo forms of LpxD in space groups P2 1 and P4 3 22. These crystals contained six and three copies of the protein molecule in the asymmetric unit and diffracted to 2.8 and 2.7 Å resolution, respectively. A comparison of the multiple protein copies in the asymmetric units of these crystals reveals a common protein conformation and a conformation in which the relative orientation between the two major domains in the protein is altered

  4. Analysis of potential risks from the bacterial communities associated with air-contact surfaces from tilapia (Oreochromis niloticus) fish farming.

    Science.gov (United States)

    Grande Burgos, Maria Jose; Romero, Jose Luis; Pérez Pulido, Rubén; Cobo Molinos, Antonio; Gálvez, Antonio; Lucas, Rosario

    2018-01-01

    Tilapia farming is a promising growing sector in aquaculture. Yet, there are limited studies on microbiological risks associated to tilapia farms. The aim of the present study was to analyse the bacterial communities from solid surfaces in contact with air in a tilapia farm in order to evaluate the presence of bacteria potentially toxinogenic or pathogenic to humans or animals. Samples from a local tilapia farm (tank wall, aerator, water outlets, sink and floor) were analyzed by high throughput sequencing technology. Sequences were assigned to operational taxonomic units (OTUs). Proteobacteria was the main phylum represented in most samples (except for one). Cyanobacteria were a relevant phylum in the inner wall from the fattening tank and the wet floor by the pre-fattening tank. Bacteroidetes were the second phylum in relative abundance for samples from the larval rearing tank and the pre-fattening tank and one sample from the fattening tank. Fusobacteria showed highest relative abundances in samples from the larval rearing tank and pre-fattening tank. Other phyla (Verrucomicrobia, Actinobacteria, Firmicutes, Planktomycetes, Acidobacteria, Chloroflexi, Chlorobi, Gemmatiomonadetes or Fibrobacters) had lower relative abundances. A large fraction of the reads (ranging from 43.67% to 72.25%) were assigned to uncultured bacteria. Genus Acinetobacter (mainly A. calcoaceticus/baumanni) was the predominant OTU in the aerator of the fattening tank and also in the nearby sink on the floor. The genera Cetobacterium and Bacteroides showed highest relative abundances in the samples from the larval rearing tank and the pre-fattening tank. Genera including fish pathogens (Fusobacterium, Aeromonas) were only detected at low relative abundances. Potential human pathogens other than Acinetobacter were either not detected or had very low relative abundances (Acinetobacter and potential cyanotoxin-producing cyanobacteria. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Molecular characterization of β-lactamase genes in clinical isolates of carbapenem-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Raible, Kevin M; Sen, Bhaswati; Law, Nancy; Bias, Tiffany E; Emery, Christopher L; Ehrlich, Garth D; Joshi, Suresh G

    2017-11-16

    Acinetobacter baumannii is a nosocomial pathogen which is establishing as a major cause of morbidity and mortality within the healthcare community. The success of this pathogen is largely due to its ability to rapidly gain resistance to antimicrobial therapies and its capability to persist in an abiotic environment through the production of a biofilm. Our tertiary-care hospital has showed high incidence of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates. In this study we explore both genotypic and phenotypic properties of 26 CRAB isolates: 16 isolates were collected from January 2010 to March 2011, and 10 were collected between February and May 2015. We determined that all 26 CRAB isolates possessed multiple β-lactamase genes, including genes from Groups A, C, and D. Specifically, 42% of the isolates possesses the potentially plasmid-borne genes of OXA-23-like or OXA-40-like β-lactamase. The presence of mobile gene element integron cassettes and/or integrases in 88% of the isolates suggests a possible mechanism of dissemination of antibiotic resistance genes. Additionally, the location of insertion sequence (IS) ISAba1 in promotor region of of the OXA-51-like, ADC-7, and ampC genes was confirmed. Multilocus sequence typing (MLST) demonstrated that all 26 CRAB isolates were either sequence type (ST)-229 or ST-2. Interestingly, ST-2 went from being the minority CRAB strain in the 2010-2011 isolates to the predominant strain in the 2015 isolates (from 32 to 90%). We show that the ST-2 strains have an enhanced ability to produce biofilms in comparison to the ST-229 strains, and this fact has potentially led to more successful colonization of the clinical environment over time. This study provides a longitudinal genetic and phenotypic survey of two CRAB sequence types, and suggests how their differing phenotypes may interact with the selective pressures of a hospital setting effecting strain dominance over a 5-year period.

  6. Induction of Diverse Bioactive Secondary Metabolites from the Mangrove Endophytic Fungus Trichoderma sp. (Strain 307 by Co-Cultivation with Acinetobacter johnsonii (Strain B2

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    Liuhong Zhang

    2017-02-01

    Full Text Available Two new sesquiterpenes, microsphaeropsisin B (1 and C (2, and two new de-O-methyllasiodiplodins, (3R, 7R-7-hydroxy-de-O-methyllasiodiplodin (4 and (3R-5-oxo-de-O-methyllasiodiplodin (5, together with one new natural product (6 and twelve known compounds (3, 7–17, were isolated from the co-cultivation of mangrove endophytic fungus Trichoderma sp. 307 and aquatic pathogenic bacterium Acinetobacter johnsonii B2. Their structures, including absolute configurations, were elucidated by extensive analysis of spectroscopic data, electronic circular dichroism, Mo2(AcO4-induced circular dichroism, and comparison with reported data. All of the isolated compounds were tested for their α-glucosidase inhibitory activity and cytotoxicity. New compounds 4 and 5 exhibited potent α-glucosidase inhibitory activity with IC50 values of 25.8 and 54.6 µM, respectively, which were more potent than the positive control (acarbose, IC50 = 703.8 µM. The good results of the tested bioactivity allowed us to explore α-glucosidase inhibitors in lasiodiplodins.

  7. Infecções hospitalares em 46 pacientes submetidos a artroplastia total do quadril Hospital infections in 46 patients submitted to total hip replacement

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    Ana Lúcia Lei Munhoz Lima

    2001-03-01

    Full Text Available Foram estudados 46 pacientes submetidos a artroplastia total do quadril em um Instituto de Ortopedia de São Paulo, Brasil, no período de 1993 a 1995, com o objetivo de obter a real frequência das infecções hospitalares da ferida operatória superficial e profunda que ocorrem nessa cirurgia. O estudo baseou-se no acompanhamento pré-operatório, trans-operatório e pós-operatório com seguimento mínimo de três meses de todos os pacientes, no sentido de caracterizar os agentes etiológicos das infecções e os fatores de risco que contribuem para o seu desenvolvimento. Foi observada uma freqüência total de 15.1% de infecções hospitalares, sendo 6.5% de infecção superficial da ferida operatória, 6.5% de infecção profunda e 2.1% de infecção do trato urinário. Os agentes etiológicos encontrados foram Pseudomonas aeruginosa (2 casos, Staphylococcus coagulase negativo (2 casos, Morganella morgani (1 caso e associação de Acinetobacter calcoaceticus (2 casos. O fator de risco com significância estatística observado nesta casuística foi o tempo cirúrgico aumentado. Concluiu-se que a frequência de infecção da ferida cirúrgica superficial e profunda nas artroplastias totais de quadril foi maior, nesta casuística, do que a relatada na literatura internacional, com elevada participação de bacilos Gram-negativos como agentes etiológicos e tendo como principal fator de risco o tempo cirúrgico aumentado.We studied 46 patients submitted to total hip replacement at an Orthopaedics Institute in the city of São Paulo, Brazil, from 1993 to 1995, in order to determine the real frequency of hospital infections of the superficial and deep surgical wounds occurring in this operation. The study consisted of preoperative, transoperative and postoperative monitoring and a minimum follow-up period of three months for all patients in order to characterise the etiologic agents of the infections and risk factors contributing to the

  8. Epidemiology of Multiresistant Acinetobacter Infections in Bulgaria

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  9. Pneumonia caused by extensive drug-resistant Acinetobacter baumannii among hospitalized patients: genetic relationships, risk factors and mortality.

    Science.gov (United States)

    Li, Yu Jun; Pan, Chu Zhi; Fang, Chang Quan; Zhao, Zhu Xiang; Chen, Hui Ling; Guo, Peng Hao; Zhao, Zi Wen

    2017-05-30

    The clonal spread of multiple drug-resistant Acinetobacter baumannii is an emerging problem in China. We analysed the molecular epidemiology of Acinetobacter baumanni isolates at three teaching hospitals and investigated the risk factors, clinical features, and outcomes of hospital-acquired pneumonia caused by extensive drug-resistant Acinetobacter baumannii (XDRAB) infection in Guangzhou, China. Fifty-two A. baumannii isolates were collected. Multilocus sequence typing (MLST) was used to assess the genetic relationships among the isolates. The bla OXA-51-like gene was amplified using polymerase chain reaction (PCR) and sequencing. The resistance phenotypes were determined using the disc diffusion method. A retrospective case-control study was performed to determine factors associated with XDRAB pneumonia. Most of the 52 A. baumannii isolates (N = 37, 71.2%) were collected from intensive care units (ICUs). The respiratory system was the most common bodily site from which A. baumannii was recovered (N = 45, 86.5%). Disc diffusion classified the isolates into 17 multidrug-resistant (MDR) and 35 extensively drug-resistant (XDR) strains. MLST grouped the A. baumannii isolates into 5 existing sequence types (STs) and 7 new STs. ST195 and ST208 accounted for 69.2% (36/52) of the isolates. The clonal relationship analysis showed that ST195 and ST208 belonged to clonal complex (CC) 92. According to the sequence-based typing (SBT) of the bla OXA-51-like gene, 51 A. baumannii isolates carried OXA-66 and the rest carried OXA-199. There were no significant differences with respect to the resistance phenotype between the CC92 and non-CC92 strains (P = 0.767). The multivariate analysis showed that the APACHE II score, chronic obstructive pulmonary disease (COPD) and cardiac disease were independent risk factors for XDRAB pneumonia (P < 0.05). The mortality rate of XDRAB pneumonia was high (up to 42.8%), but pneumonia caused by XDRAB was not associated with in

  10. Emission of extensively-drug-resistant Acinetobacter baumannii from hospital settings to the natural environment.

    Science.gov (United States)

    Seruga Music, M; Hrenovic, J; Goic-Barisic, I; Hunjak, B; Skoric, D; Ivankovic, T

    2017-08-01

    Acinetobacter baumannii is a leading emerging pathogen that is frequently recovered from patients during hospital outbreaks. The role of environmental A. baumannii reservoirs is therefore of great concern worldwide. To investigate the connection between A. baumannii causing hospital outbreaks and environmental isolates from hospital wastewater, urban sewage and river water as the final natural recipient of wastewaters. Clinical isolates from patients with hospital-acquired pneumonia and environmental isolates from water were collected during a two-month monitoring period. Recovery of A. baumannii was performed using CHROMagar Acinetobacter plates, incubated at 42°C for 48 h. Identification was performed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and analyses of rpoB gene. The antibiotic resistance profiles were interpreted according to criteria given for clinical isolates of A. baumannii. The sequence types (ST) were retrieved by multi-locus sequence typing. Fourteen of 19 isolates recovered from patients, hospital wastewaters, urban sewage and river water belonged to ST-195. The remaining five isolates recovered from patients and river water were assigned to ST-1421. All isolates showed very strong relatedness and clustered into CC92, which corresponds to IC2. All isolates were non-susceptible to at least one agent in all but two or fewer antimicrobial categories, and thus were classified as 'extensively-drug-resistant' (XDR). Heteroresistance to colistin was found in two isolates from hospital wastewater. Close relatedness of clinical and environmental isolates suggests the emission of XDR A. baumannii via the untreated hospital wastewater in the natural environment. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  11. Carbapenem Breakpoints for Acinetobacter baumannii Group: Supporting Clinical Outcome Data from Patients with Bacteremia.

    Science.gov (United States)

    Lee, Yi-Tzu; Chiang, Mei-Chun; Kuo, Shu-Chen; Wang, Yung-Chih; Lee, I-Hsin; Chen, Te-Li; Yang, Ya-Sung

    2016-01-01

    The carbapenem breakpoints set by different organizations for Acinetobacter are discordant, but supporting clinical data are lacking. This study aimed to provide the first clinical outcome data to support the carbapenem breakpoints for Acinetobacter baumannii (Ab) group in patients with bacteremia. This study included 117 adults who received carbapenems for treatment of Ab group bacteremia in Taipei Veterans General Hospital over an 8-year period. We analyzed 30-day mortality rates among patient groups acquiring isolates with different carbapenem minimal inhibitory concentrations (MICs). The carbapenem MIC breakpoint derived from classification and regression tree (CART) analysis to delineate the risk of 30-day mortality was between MICs of ≤ 4 mg/L and ≥ 8 mg/L. Mortality rate was higher in patients acquiring isolates with carbapenem MIC ≥ 8 mg/L than ≤ 4 mg/L, by bivariate (54.9% [28/51] vs 25.8% [17/66]; P = 0.003) and survival analysis (P = 0.001 by log-rank test). Multivariate analysis using logistic regression and Cox regression models including severity of illness indices demonstrated that treating patients with Ab group bacteremia caused by isolates with a carbapenem MIC ≥ 8 mg/L with carbapenem was an independent predictor of 30-day mortality (odds ratio, 5.125; 95% confidence interval [CI], 1.946-13.498; P = 0.001, and hazard ratio, 2.630; 95% CI, 1.431-4.834; P = 0.002, respectively). The clinical outcome data confirmed that isolates with MIC ≤ 4 mg/L were susceptible to carbapenem, and those with MIC ≥ 8 mg/L were resistant in patients with Ab group bacteremia.

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

    Science.gov (United States)

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

    2016-11-01

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

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

    OpenAIRE

    Rodríguez Calviño, Fabiola

    2012-01-01

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

  14. Transcriptome profiling in imipenem-selected Acinetobacter baumannii.

    Science.gov (United States)

    Chang, Kai-Chih; Kuo, Han-Yueh; Tang, Chuan Yi; Chang, Cheng-Wei; Lu, Chia-Wei; Liu, Chih-Chin; Lin, Huei-Ru; Chen, Kuan-Hsueh; Liou, Ming-Li

    2014-09-26

    Carbapenem-resistance in Acinetobacter baumannii has gradually become a global challenge. To identify the genes involved in carbapenem resistance in A. baumannii, the transcriptomic responses of the completely sequenced strain ATCC 17978 selected with 0.5 mg/L (IPM-2 m) and 2 mg/L (IPM-8 m) imipenem were investigated using RNA-sequencing to identify differences in the gene expression patterns. A total of 88 and 68 genes were differentially expressed in response to IPM-2 m and IPM-8 m selection, respectively. Among the expressed genes, 50 genes were highly expressed in IPM-2 m, 30 genes were highly expressed in IPM-8 m, and 38 genes were expressed common in both strains. Six groups of genes were simultaneously expressed in IPM-2 m and IPM-8 m mutants. The three gene groups involved in DNA recombination were up-regulated, including recombinase, transposase and DNA repair, and beta-lactamase OXA-95 and homologous recombination. The remaining gene groups involved in biofilm formation were down-regulated, including quorum sensing, secretion systems, and the csu operon. The antibiotic resistance determinants, including RND efflux transporters and multidrug resistance pumps, were over-expressed in response to IPM-2 m selection, followed by a decrease in response to IPM-8 m selection. Among the genes over-expressed in both strains, blaOXA-95, previously clustered with the blaOXA-51-like family, showed 14-fold (IPM-2 m) to 330-fold (IPM-8 m) over-expression. The expression of blaOXA-95 in IPM-2 m and IPM-8 m cells was positively correlated with the rate of imipenem hydrolysis, as demonstrated through Liquid Chromatography-Mass Spectrometry/Mass Spectrometry, suggesting that blaOXA-95 plays a critical role in conferring carbapenem resistance. In addition, A. baumannii shows an inverse relationship between carbapenem resistance and biofilm production. Gene recombination and blaOXA-95 play critical roles in carbapenem resistance in A. baumannii. Taken together, the results of

  15. Expression, purification, crystallization and preliminary crystallographic analysis of the phosphoglycerate kinase from Acinetobacter baumannii

    International Nuclear Information System (INIS)

    Baretta, Kayla; Garen, Craig; Yin, Jiang; James, Michael N. G.

    2012-01-01

    Approximately five decades have passed with only one or two new antibiotics making it into clinical use. Phosphoglycerate kinase from A. baumanii has been selected as a potential target for antibiotic development; this paper presents the initial structural biological results from this research. Acinetobacter baumannii is a common multidrug-resistant clinical pathogen that is often found in hospitals. The A. baumannii phosphoglycerate kinase (AbPGK) is involved in the key energy-producing pathway of glycolysis and presents a potential target for antibiotic development. AbPGK has been expressed and purified; it was crystallized using lithium sulfate as the precipitant. The AbPGK crystals belonged to space group P222 1 . They diffracted to a resolution of 2.5 Å using synchrotron radiation at the Canadian Light Source

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

    OpenAIRE

    Sardini, Rima Novia

    2015-01-01

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

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

    Science.gov (United States)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  19. Purification, crystallization and preliminary X-ray crystallographic analysis of diaminopimelate epimerase from Acinetobacter baumannii

    International Nuclear Information System (INIS)

    Park, Jeong Soon; Lee, Woo Cheol; Song, Jung Hyun; Kim, Seung Il; Lee, Je Chul; Cheong, Chaejoon; Kim, Hye-Yeon

    2012-01-01

    The crystallization and preliminary X-ray crystallographic analysis of diaminopimelate epimerase from A. baumannii are reported. The meso isomer of diaminopimelate (meso-DAP) is a biosynthetic precursor of l-lysine in bacteria and plants, and is a key component of the peptidoglycan layer in the cell walls of Gram-negative and some Gram-positive bacteria. Diaminopimelate epimerase (DapF) is a pyridoxal-5′-phosphate-independent racemase which catalyses the interconversion of (6S,2S)-2,6-diaminopimelic acid (ll-DAP) and meso-DAP. In this study, DapF from Acinetobacter baumannii was overexpressed in Escherichia coli strain SoluBL21, purified and crystallized using a vapour-diffusion method. A native crystal diffracted to a resolution of 1.9 Å and belonged to space group P3 1 or P3 2 , with unit-cell parameters a = b = 74.91, c = 113.35 Å, α = β = 90, γ = 120°. There were two molecules in the asymmetric unit

  20. Bioinformatic analysis of phage AB3, a phiKMV-like virus infecting Acinetobacter baumannii.

    Science.gov (United States)

    Zhang, J; Liu, X; Li, X-J

    2015-01-16

    The phages of Acinetobacter baumannii has drawn increasing attention because of the multi-drug resistance of A. baumanni. The aim of this study was to sequence Acinetobacter baumannii phage AB3 and conduct bioinformatic analysis to lay a foundation for genome remodeling and phage therapy. We isolated and sequenced A. baumannii phage AB3 and attempted to annotate and analyze its genome. The results showed that the genome is a double-stranded DNA with a total length of 31,185 base pairs (bp) and 97 open reading frames greater than 100 bp. The genome includes 28 predicted genes, of which 24 are homologous to phage AB1. The entire coding sequence is located on the negative strand, representing 90.8% of the total length. The G+C mol% was 39.18%, without areas of high G+C content over 200 bp in length. No GC island, tRNA gene, or repeated sequence was identified. Gene lengths were 120-3099 bp, with an average of 1011 bp. Six genes were found to be greater than 2000 bp in length. Genomic alignment and phylogenetic analysis of the RNA polymerase gene showed that similar to phage AB1, phage AB3 is a phiKMV-like virus in the T7 phage family.

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

    Science.gov (United States)

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

    2015-01-01

    SUMMARY Actinetobacter baumannii is an important nosocomial pathogen that can cause a wide range of serious conditions including pneumonia, meningitis, necrotizing fasciitis and sepsis. It is also a major cause of wound infections in military personnel injured during the conflicts in Afghanistan and Iraq, leading to its popular nickname of ‘Iraqibacter’. Contributing to its success in clinical settings is resistance to environmental stresses such as desiccation and disinfectants. Moreover, in recent years there has been a dramatic increase in the number of A. baumannii strains with resistance to multiple antibiotic classes. Acinetobacter baumannii is an inhabitant of oral biofilms, which can act as a reservoir for pneumonia and chronic obstructive pulmonary disease. Subgingival colonization by A. baumannii increases the risk of refractory periodontitis. Pathogenesis of the organism involves adherence, biofilm formation and iron acquisition. In addition, A. baumannii can induce apoptotic cell death in epithelial cells and kill hyphal forms of Candida albicans. Virulence factors that have been identified include pili, the outer membrane protein OmpA, phospholipases and extracellular polysaccharide. Acinetobacter baumannii can sense blue light through a blue-light sensing using flavin (BLUF) domain protein, BlsA. The resulting conformational change in BlsA leads to changes in gene expression, including virulence genes. PMID:25052812

  2. Whole-genome pyrosequencing of an epidemic multidrug-resistant Acinetobacter baumannii strain belonging to the European clone II group

    DEFF Research Database (Denmark)

    Iacono, M.; Villa, L.; Fortini, D.

    2008-01-01

    The whole-genome sequence of an epidemic, multidrug-resistant Acinetobacter baumannii strain (strain ACICU) belonging to the European clone II group and carrying the plasmid-mediated bla(OXA-58) carbapenem resistance gene was determined. The A. baumannii ACICU genome was compared with the genomes...

  3. A Case of Acinetobacter Septic Pulmonary Embolism in an Infant

    Directory of Open Access Journals (Sweden)

    Poonam Wade

    2016-01-01

    Full Text Available Case Characteristics. An 11-month-old girl presented with fever and breathlessness for 5 days. Patient had respiratory distress with bilateral coarse crepitations. Chest radiograph revealed diffuse infiltrations in the right lung with thick walled cavities in mid and lower zone. Computed tomography showed multiple cystic spaces and emboli. Blood culture grew Acinetobacter species. Intervention. Patient was treated with Meropenem and Vancomycin. Outcome. Complete clinical and radiological recovery was seen in child. Message. Blood cultures and CT of the chest are invaluable in the evaluation of a patient with suspected septic pulmonary embolism. With early diagnosis and appropriate antimicrobial therapy, complete recovery can be expected in patients with septic pulmonary embolism.

  4. OXA beta-lactamase-mediated carbapenem resistance in Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    S M Amudhan

    2011-01-01

    Full Text Available Objectives: Acinetobacter baumannii is a significant pathogen in health care settings. In recent years, an increase in carbapenem resistance among A. baumannii due to Ambler class B metallo-beta-lactamases or class D OXA carbapenamases has been reported. In this study we detected the presence of OXA carbapenamases and coproduction of metallo-beta-lactamases (blaVIM and blaIMP by phenotypic and genotypic methods in carbapenem resistant clinical isolates of Acinetobacter baumannii. Materials and Methods: A total of 116 consecutive, non-duplicate carbapenem resistant A. baumannii isolated from various clinical specimens were included in the study. The modified Hodge test and inhibitor potentiated disk diffusion tests were done for the screening of carbapenamase and metallo-beta-lactamase production, respectively. Polymerase chain reaction (PCR was performed for the detection of OXA (blaOXA 23 like, blaOXA 24 like, blaOXA-51 like and blaOXA-58 like genes and metallo-beta-lactamases (blaVIM and blaIMP genes. Gene sequencing was performed for representative isolates. Results: Among 116 A. baumannii, OXA genes were detected in 106 isolates. BlaOXA 51 like (n = 99 and blaOXA -23 like (n = 95 were the most common and they coexisted in 89 isolates. blaOXA-24 like gene was detected in two isolates of which one also carried blaOXA-51 like and blaOXA-58 like genes. The modified Hodge test was positive in 113 isolates. The metallo-beta-lactamase screening test was positive in 92 isolates. blavim was detected in 54 isolates of which 1 also carried the blaIMP gene. Conclusions: blaOXA-23 like and bla OXA 51 like genes are the most common types of OXA carbapenamases while the blaVIM type is the most common type of metallo-beta-lactamase contributing to carbapenem resistance in clinical isolates of A. baumannii. The coproduction of OXA and metallo-beta-lactamases is not an uncommon phenomenon in A. baumannii.

  5. Database for the ampC alleles in Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Nabil Karah

    Full Text Available Acinetobacter baumannii is a troublesome opportunistic pathogen with a high capacity for clonal dissemination. We announce the establishment of a database for the ampC locus in A. baumannii, in which novel ampC alleles are differentiated based on the occurrence of ≥ 1 nucleotide change, regardless of whether it is silent or missense. The database is openly accessible at the pubmlst platform for A. baumannii (http://pubmlst.org/abaumannii/. Forty-eight distinctive alleles of the ampC locus have so far been identified and deposited in the database. Isolates from clonal complex 1 (CC1, according to the Pasteur multilocus sequence typing scheme, had a variety of the ampC locus alleles, including alleles 1, 3, 4, 5, 6, 7, 8, 13, 14, 17, and 18. On the other hand, isolates from CC2 had the ampC alleles 2, 3, 19, 20, 21, 22, 23, 24, 26, 27, 28, and 46. Allele 3 was characteristic for sequence types ST3 or ST32. The ampC alleles 10, 16, and 25 were characteristic for CC10, ST16, and CC25, respectively. Our study points out that novel gene databases, in which alleles are numbered based on differences in their nucleotide identities, should replace traditional records that use amino acid substitutions to define new alleles.

  6. The tetracycline resistance determinant Tet 39 and the sulphonamide resistance gene sulII are common among resistant Acinetobacter spp. isolated from integrated fish farms in Thailand

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Petersen, Andreas

    2007-01-01

    Objectives: To determine the genetic basis for tetracycline and sulphonamide resistance and the prevalence of class I and II integrons in oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Methods: A total of 222 isolates were screened for tetracycline resistance...... and Southern blots with sulII and tet(39) probes were performed on selected isolates. Results: The recently identified tetracycline resistance gene tet(39) was demonstrated in 75% (166/222) of oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Isolates that were also...

  7. Enzymic Dehalogenation of 4-Chlorobenzoyl Coenzyme A in Acinetobacter sp. Strain 4-CB1

    OpenAIRE

    Copley, Shelley D.; Crooks, Gwen P.

    1992-01-01

    4-Chlorobenzoate degradation in cell extracts of Acinetobacter sp. strain 4-CB1 occurs by initial synthesis of 4-chlorobenzoyl coenzyme A (4-chlorobenzoyl CoA) from 4-chlorobenzoate, CoA, and ATP. 4-Chlorobenzoyl CoA is dehalogenated to 4-hydroxybenzoyl CoA. Following the dehalogenation reaction, 4-hydroxybenzoyl CoA is hydrolyzed to 4-hydroxybenzoate and CoA. Possible roles for the CoA moiety in the dehalogenation reaction are discussed.

  8. Enzymic Dehalogenation of 4-Chlorobenzoyl Coenzyme A in Acinetobacter sp. Strain 4-CB1

    Science.gov (United States)

    Copley, Shelley D.; Crooks, Gwen P.

    1992-01-01

    4-Chlorobenzoate degradation in cell extracts of Acinetobacter sp. strain 4-CB1 occurs by initial synthesis of 4-chlorobenzoyl coenzyme A (4-chlorobenzoyl CoA) from 4-chlorobenzoate, CoA, and ATP. 4-Chlorobenzoyl CoA is dehalogenated to 4-hydroxybenzoyl CoA. Following the dehalogenation reaction, 4-hydroxybenzoyl CoA is hydrolyzed to 4-hydroxybenzoate and CoA. Possible roles for the CoA moiety in the dehalogenation reaction are discussed. PMID:16348702

  9. Clinical and molecular epidemiology of Acinetobacter baumannii bloodstream infections in an endemic setting.

    Science.gov (United States)

    Marchaim, Dror; Levit, Dana; Zigron, Roy; Gordon, Michal; Lazarovitch, Tsillia; Carrico, Joao A; Chalifa-Caspi, Vered; Moran-Gilad, Jacob

    2017-03-01

    The transmission dynamics of Acinetobacter baumannii in endemic settings, and the relation between microbial properties and patients' clinical outcomes, are yet obscure and hampered by insufficient metadata. Of 20 consecutive patients with A. baumannii bloodstream infection that were thoroughly analyzed at a single center, at least one transmission opportunity was evident for 85% of patients. This implies that patient-to-patient transmission is the major mode of A. baumannii acquisitions in health facilities. Moreover, all patients who died immediately (baumannii ST457 lineage compared with other strains.

  10. Novel 3D porous semi-IPN hydrogel scaffolds of silk sericin and poly(N-hydroxyethyl acrylamide for dermal reconstruction

    Directory of Open Access Journals (Sweden)

    S. Ross

    2017-09-01

    Full Text Available In this work, a novel semi-interpenetrating polymer network (semi-IPN hydrogel scaffold based on silk sericin (SS and poly(N-hydroxyethyl acrylamide (PHEA was successfully fabricated via conventional free-radical polymerization. The porous structure of the scaffolds was introduced using a lyophilization technique and the effect of cross-linker (XL on morphology, gelation time and physical properties of hydrogel scaffold was first studied. The results show that using low cross-linker content (0.125, 0.25 and 0.5 wt% XL produced flexible scaffolds and appropriate gelation times for fabricating the scaffold. Therefore, the polymerization system with a constant percentage of XL at 0.5 wt% was chosen to study further the effect of SS on the physical properties and cell culture of the scaffolds. It was observed that the hydrogel scaffold of PHEA without SS (PHEA/SS-0 had no cell proliferation, whereas hydrogel scaffolds with SS enhanced cell viability when compared to the positive control. The sample of PHEA/SS at 1.25 wt% of SS and 0.5 wt% of cross-linker was the most suitable for HFF-1 cells to migrate and cell proliferation due to possessing a connective porous structure, along with silk sericin. The results proved that this novel porous semi-IPN hydrogel has the potential to be used as dermal reconstruction scaffold.

  11. LEVANTAMENTO EPIDEMIOLÓGICO DE INFECÇÃO POR ACINETOBACTER SPP EM AMOSTRAS DE HEMOCULTURAS DE UM LABORATÓRIO DE SÃO JOSÉ DOS CAMPOS

    Directory of Open Access Journals (Sweden)

    Vânia Waleska Sousa da Cunha

    2015-01-01

    Full Text Available A presença de infecções na corrente sanguínea representa uma grave complicação na situação de pacientes críticos, podendo aumentar os riscos de morbidade e mortalidade, sendo a hemocultura um importante recurso no diagnóstico do agente microbiano. Entre as bactérias causadoras de bacteriemia, encontramos, frequentemente, a Acinetobacter spp, sendo um patógeno de grande importância clínica devido ao aumento de sua frequência como causa de infecções hospitalares e, também, por, normalmente, apresentar multirresistência aos agentes antimicrobianos de prática clínica. O presente estudo teve como finalidade o levantamento epidemiológico de infecções em hemoculturas causadas pelo gênero Acinetobacter spp em pacientes internados, em hospitais de São José dos Campos-SP, demonstrando sua prevalência no munícipio. Os dados analisados foram fornecidos pelo sistema de um laboratório de análises microbiológicas e utilizados para o levantamento de infecções por Acinetobacter spp em hemoculturas, no período de agosto de 2012 a agosto de 2013. Foram avaliados 5.759 exames de hemocultura, com 1.019 resultados positivos, sendo que Acinetobacter baumannii foi identificada em 31 amostras, correspondendo ao sexto patógeno mais isolado (3,04% das hemoculturas positivas. A. baumannii se tornou um patógeno de grande preocupação hospitalar, devido à sua crescente colonização nas Unidades de Tratamento Intensivo e sua multirresistência aos antimicrobianos.

  12. Assessment of intra-species diversity among strains of Acinetobacter baumannii isolated from sites contaminated with petroleum hydrocarbons

    International Nuclear Information System (INIS)

    Manab Sarma, P.; Bhattacharya, D.; Krishnan, S.; Lal, B.

    2004-01-01

    Intra-species diversity among Acinetobacter baumannii strains isolated from crude oil-contaminated soils from different geographic regions in India was assessed, including their capability to degrade different fractions of total petroleum hydrocarbons. A total of 96 strains were isolated from five different sites. Of the 96 isolates, 25 strains were identified as Acinetobacter baumannii; all of these strains were biochemically profiled and grouped into eight phenovars on the basis of multivariate analysis of their substrate utilization profiles. All strains were able to degrade the total petroleum hydrocarbon fractions of crude oil. Intraspecies relatedness among the 25 strains was determined using tRNA intergenic spacer length polymorphism. Specific variants among the strains with different degradation capacities for different fractions of crude oil were detected. Environmental influences that cause intra-species diversity, such as functional resilience, within the selected strains of A. baumannii were also noted. It is suggested that such diversities may make it possible to select contaminant-specific strains for efficient biotechnological strategies in environmental remediation. 19 refs., 4 tabs., 3 figs

  13. Assessment of intra-species diversity among strains of Acinetobacter baumannii isolated from sites contaminated with petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Manab Sarma, P.; Bhattacharya, D.; Krishnan, S. [TERI School of Advanced Studies, Center of Bioresources and Biotechnology, New Delhi (India); Lal, B. [TERI School of Advanced Studies, Microbial Biotechnology Division, New Delhi (India)

    2004-06-01

    Intra-species diversity among Acinetobacter baumannii strains isolated from crude oil-contaminated soils from different geographic regions in India was assessed, including their capability to degrade different fractions of total petroleum hydrocarbons. A total of 96 strains were isolated from five different sites. Of the 96 isolates, 25 strains were identified as Acinetobacter baumannii; all of these strains were biochemically profiled and grouped into eight phenovars on the basis of multivariate analysis of their substrate utilization profiles. All strains were able to degrade the total petroleum hydrocarbon fractions of crude oil. Intraspecies relatedness among the 25 strains was determined using tRNA intergenic spacer length polymorphism. Specific variants among the strains with different degradation capacities for different fractions of crude oil were detected. Environmental influences that cause intra-species diversity, such as functional resilience, within the selected strains of A. baumannii were also noted. It is suggested that such diversities may make it possible to select contaminant-specific strains for efficient biotechnological strategies in environmental remediation. 19 refs., 4 tabs., 3 figs.

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

    Science.gov (United States)

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

    2012-06-01

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

  15. Stereochemical insignificance discovered in Acinetobacter baumannii quorum sensing.

    Directory of Open Access Journals (Sweden)

    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.

  16. Structural and physiochemical characterization of rhamnolipids produced by Acinetobacter calcoaceticus, Enterobacter asburiae and Pseudomonas aeruginosa in single strain and mixed cultures

    Czech Academy of Sciences Publication Activity Database

    Hošková, M.; Ježdík, R.; Schreiberová, O.; Chudoba, J.; Šír, M.; Čejková, A.; Masák, J.; Jirků, V.; Řezanka, Tomáš

    2015-01-01

    Roč. 193, JAN 2015 (2015), s. 45-51 ISSN 0168-1656 R&D Projects: GA ČR GA14-00227S; GA ČR(CZ) GAP503/11/0215 Institutional support: RVO:61388971 Keywords : Biosurfactants * Bioreactor cultivation * ESI MS/MS Subject RIV: EE - Microbiology, Virology Impact factor: 2.667, year: 2015

  17. 5,7-Di-N-acetyl-8-epiacinetaminic acid: A new non-2-ulosonic acid found in the K73 capsule produced by an Acinetobacter baumannii isolate from Singapore.

    Science.gov (United States)

    Kenyon, Johanna J; Notaro, Anna; Hsu, Li Yang; De Castro, Cristina; Hall, Ruth M

    2017-09-12

    Nonulosonic acids are found in the surface polysaccharides of many bacterial species and are often implicated in pathogenesis. Here, the structure of a novel 5,7-diacetamido-3,5,7,9-tetradeoxynon-2-ulosonic acid recovered from the capsular polysaccharide of a multiply antibiotic resistant Acinetobacter baumannii isolate was determined. The isolate carries a sugar synthesis module that differs by only a single gene from the module for the synthesis of 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-altro-non-2-ulosonic acid or 5,7-di-N-acetylacinetaminic acid, recently discovered in the capsule of another A. baumannii isolate. The new monosaccharide is the C8-epimer of acinetaminic acid (8eAci; 5,7-diacetamido-3,5,7,9-tetradeoxy-D-glycero-L-altro-non-2-ulosonic acid) and the C7-epimer of legionaminic acid. This monosaccharide had not previously been detected in a biological sample but had been synthesized chemically.

  18. Evaluation of the ability of Acinetobacter baumannii to form biofilms on six different biomedical relevant surfaces.

    Science.gov (United States)

    Greene, C; Wu, J; Rickard, A H; Xi, C

    2016-10-01

    The human opportunistic pathogen, Acinetobacter baumannii, has the propensity to form biofilms and frequently cause medical device-related infections in hospitals. However, the physio-chemical properties of medical surfaces, in addition to bacterial surface properties, will affect colonization and biofilm development. The objective of this study was to compare the ability of A. baumannii to form biofilms on six different materials common to the hospital environment: glass, porcelain, stainless steel, rubber, polycarbonate plastic and polypropylene plastic. Biofilms were developed on material coupons in a CDC biofilm reactor. Biofilms were visualized and quantified using fluorescent staining and imaged using confocal laser scanning microscopy (CLSM) and by direct viable cell counts. Image analysis of CLSM stacks indicated that the mean biomass values for biofilms grown on glass, rubber, porcelain, polypropylene, stainless steel and polycarbonate were 0·04, 0·26, 0·62, 1·00, 2·08 and 2·70 μm(3) /μm(2) respectively. Polycarbonate developed statistically more biofilm mass than glass, rubber, porcelain and polypropylene. Viable cell counts data were in agreement with the CLSM-derived data. In conclusion, polycarbonate was the most accommodating surface for A. baumannii ATCC 17978 to form biofilms while glass was least favourable. Alternatives to polycarbonate for use in medical and dental devices may need to be considered. In the hospital environment, Acinetobacter baumannii is one of the most persistent and difficult to control opportunistic pathogens. The persistence of A. baumannii is due, in part, to its ability to colonize surfaces and form biofilms. This study demonstrates that A. baumannii can form biofilms on a variety of different surfaces and develops substantial biofilms on polycarbonate - a thermoplastic material that is often used in the construction of medical devices. The findings highlight the need to further study the in

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

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Guardabassi, L.

    2005-01-01

    A novel tetracycline resistance determinant named Tet 39 was found in unrelated Acinetobacter strains isolated from freshwater trout farms (n=4) and sewage (n=6) in Denmark, and from a clinical specimen in the Netherlands (n=1). The determinant was located on transferable plasmids and consisted o...

  20. Isolation and characterization of diesel degrading bacteria, Sphingomonas sp. and Acinetobacter junii from petroleum contaminated soil

    Science.gov (United States)

    Zhang, Qiuzhuo; Wang, Duanchao; Li, Mengmeng; Xiang, Wei-Ning; Achal, Varenyam

    2014-03-01

    Two indigenous bacteria of petroleum contaminated soil were characterized to utilize diesel fuel as the sole carbon and energy sources in this work. 16S rRNA gene sequence analysis identified these bacteria as Sphingomonas sp. and Acinetobacter junii. The ability to degrade diesel fuel has been demonstrated for the first time by these isolates. The results of IR analyses showed that Sphingomonas sp. VA1 and A. junii VA2 degraded up to 82.6% and 75.8% of applied diesel over 15 days, respectively. In addition, Sphingomonas sp. VA1 possessed the higher cellular hydrophobicities of 94% for diesel compared to 81% by A. junii VA2. The isolates Sphingomonas sp. VA1 and A. junii VA2 exhibited 24% and 18%, respectively emulsification activity. This study reports two new diesel degrading bacterial species, which can be effectively used for bioremediation of petroleum contaminated sites.

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

    Science.gov (United States)

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

    2017-10-01

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

  2. Bacterial community analysis in chlorpyrifos enrichment cultures via DGGE and use of bacterial consortium for CP biodegradation.

    Science.gov (United States)

    Akbar, Shamsa; Sultan, Sikander; Kertesz, Michael

    2014-10-01

    The organophosphate pesticide chlorpyrifos (CP) has been used extensively since the 1960s for insect control. However, its toxic effects on mammals and persistence in environment necessitate its removal from contaminated sites, biodegradation studies of CP-degrading microbes are therefore of immense importance. Samples from a Pakistani agricultural soil with an extensive history of CP application were used to prepare enrichment cultures using CP as sole carbon source for bacterial community analysis and isolation of CP metabolizing bacteria. Bacterial community analysis (denaturing gradient gel electrophoresis) revealed that the dominant genera enriched under these conditions were Pseudomonas, Acinetobacter and Stenotrophomonas, along with lower numbers of Sphingomonas, Agrobacterium and Burkholderia. Furthermore, it revealed that members of Bacteroidetes, Firmicutes, α- and γ-Proteobacteria and Actinobacteria were present at initial steps of enrichment whereas β-Proteobacteria appeared in later steps and only Proteobacteria were selected by enrichment culturing. However, when CP-degrading strains were isolated from this enrichment culture, the most active organisms were strains of Acinetobacter calcoaceticus, Pseudomonas mendocina and Pseudomonas aeruginosa. These strains degraded 6-7.4 mg L(-1) day(-1) of CP when cultivated in mineral medium, while the consortium of all four strains degraded 9.2 mg L(-1) day(-1) of CP (100 mg L(-1)). Addition of glucose as an additional C source increased the degradation capacity by 8-14 %. After inoculation of contaminated soil with CP (200 mg kg(-1)) disappearance rates were 3.83-4.30 mg kg(-1) day(-1) for individual strains and 4.76 mg kg(-1) day(-1) for the consortium. These results indicate that these organisms are involved in the degradation of CP in soil and represent valuable candidates for in situ bioremediation of contaminated soils and waters.

  3. Cyanuric acid biodegradation by a mixed bacterial culture of Agrobacterium tumefaciens and Acinetobacter sp. in a packed bed biofilm reactor.

    Science.gov (United States)

    Galíndez-Nájera, S P; Llamas-Martínez, M A; Ruiz-Ordaz, N; Juárez-Ramírez, C; Mondragón-Parada, M E; Ahuatzi-Chacón, D; Galíndez-Mayer, J

    2009-02-01

    Cyanuric acid (1,3,5-triazine-2,4,6-triol [OOOT]) is a common biodegradation byproduct of triazinic herbicides, frequently accumulated in soils or water when supplementary carbon sources are absent. A binary bacterial culture able to degrade OOOT was selected through a continuous selection process accomplished in a chemostat fed with a mineral salt (MS) medium containing cyanuric acid as the sole carbon and nitrogen source. By sequence comparison of their 16S rDNA amplicons, bacterial strains were identified as Agrobacterium tumefaciens, and Acinetobacter sp. When the binary culture immobilized in a packed bed reactor (PBR) was fed with MS medium containing OOOT (50 mg L(-1)), its removal efficiencies were about 95%; when it was fed with OOOT plus glucose (120 mg L(-1)) as a supplementary carbon source, its removal efficiencies were closer to 100%. From sessile cells, attached to PBR porous support, or free cells present in the outflowing medium, DNA was extracted and used for Random Amplification of Polymorphic DNA analysis. Electrophoretic patterns obtained were compared to those of pure bacterial strains, a clear predominance of A. tumefaciens in PBR was observed. Although in continuous suspended cell culture, a stable binary community could be maintained, the attachment capability of A. tumefaciens represented a selective advantage over Acinetobacter sp. in the biofilm reactor, favoring its predominance in the porous stone support.

  4. Assessment of the microbiological safety of dried spices and herbs commercialized in Spain.

    Science.gov (United States)

    Sospedra, Isabel; Soriano, Jose M; Mañes, Jordi

    2010-12-01

    Spices and herbs are natural products or their blends that must be free of extraneous matter content. Conventional production of these products implicates a number of hygienic problems so spices and herbs may be exposed to a wide range of microbial contamination during pre- and post-harvest and they can present high microbial counts. In this study, we have analyzed the microbial quality of 53 samples of spices and dry herbs collected from Spanish markets detecting a contamination of samples of spices with mesophilic aerobic counts (10%) and Enterobacteriaceae (20%). The analysis from herbs showed that the percentage of contamination was 26% in both microbiological values. Pathogenic microorganisms like Staphylococcus aureus, Yersinia intermedia, Shigella spp., Enterobacter spp., Acinetobacter calcoaceticus and Hafni alvei were also isolated from spices and herbs. These unsatisfactory results showed a poor microbiological quality. Spices and dry herbs are used as ingredients in a variety of products prepared in different ways, this fact suggests the need to provide a control system to improve the quality of herbs and spices.

  5. Exploration of hydrocarbon degrading bacteria on soils contaminated by crude oil from South Sumatera

    Directory of Open Access Journals (Sweden)

    A. Napoleon

    2014-07-01

    Full Text Available The goal of this research was to explore hydrocarbon degrading bacteria on crude oil contaminated soil with potential to degrade hydrocarbon in oil pollutant. The research started by early August 2013 till January 2014. Soil sampling for this research was taken on several places with contaminated soil location such as Benakat, Rimau, and Pengabuan all of it located in South Sumatera. Conclusion from this research Isolates obtained from three (3 sites of contaminated soil and treated using SBS medium were Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pnumoniae, Streptococcus beta hemolisa, Proteus mirabilis, Staphylococcus epidermis and Acinotobacter calcoaceticus. Isolates that survived on 300 ppm of hydrocarbon concentration were Bacillus cereus, Pseudomonas aeruginosa and Acinetobacter cakciaceticus Selected isolates posses the ability to degrade hydrocarbon by breaking hydrocarbon substance as the energy source to support isolates existence up to 1,67 TPH level. Based on results accomplish by this research, we urge for further research involving the capacity of isolates to degrade wide variety of hydrocarbon substance and more to develop the potential of these bacteria for bioremediation.

  6. Antibiotic Resistance Determinant-Focused Acinetobacter baumannii Vaccine Designed Using Reverse Vaccinology.

    Science.gov (United States)

    Ni, Zhaohui; Chen, Yan; Ong, Edison; He, Yongqun

    2017-02-21

    As one of the most influential and troublesome human pathogens, Acinetobacter baumannii ( A. baumannii ) has emerged with many multidrug-resistant strains. After collecting 33 complete A. baumannii genomes and 84 representative antibiotic resistance determinants, we used the Vaxign reverse vaccinology approach to predict classical type vaccine candidates against A. baumannii infections and new type vaccine candidates against antibiotic resistance. Our genome analysis identified 35 outer membrane or extracellular adhesins that are conserved among all 33 genomes, have no human protein homology, and have less than 2 transmembrane helices. These 35 antigens include 11 TonB dependent receptors, 8 porins, 7 efflux pump proteins, and 2 fimbrial proteins (FilF and CAM87009.1). CAM86003.1 was predicted to be an adhesin outer membrane protein absent from 3 antibiotic-sensitive strains and conserved in 21 antibiotic-resistant strains. Feasible anti-resistance vaccine candidates also include one extracellular protein (QnrA), 3 RND type outer membrane efflux pump proteins, and 3 CTX-M type β-lactamases. Among 39 β-lactamases, A. baumannii CTX-M-2, -5, and -43 enzymes are predicted as adhesins and better vaccine candidates than other β-lactamases to induce preventive immunity and enhance antibiotic treatments. This report represents the first reverse vaccinology study to systematically predict vaccine antigen candidates against antibiotic resistance for a microbial pathogen.

  7. Identification of antibiotic resistance genes in the multidrug-resistant Acinetobacter baumannii strain, MDR-SHH02, using whole-genome sequencing.

    Science.gov (United States)

    Wang, Hualiang; Wang, Jinghua; Yu, Peijuan; Ge, Ping; Jiang, Yanqun; Xu, Rong; Chen, Rong; Liu, Xuejie

    2017-02-01

    This study aimed to investigate antibiotic resistance genes in the multidrug-resistant (MDR) Acinetobacter baumannii (A. baumanii) strain, MDR-SHH02, using whole‑genome sequencing (WGS). The antibiotic resistance of MDR-SHH02 isolated from a patient with breast cancer to 19 types of antibiotics was determined using the Kirby‑Bauer method. WGS of MDR-SHH02 was then performed. Following quality control and transcriptome assembly, functional annotation of genes was conducted, and the phylogenetic tree of MDR-SHH02, along with another 5 A. baumanii species and 2 Acinetobacter species, was constructed using PHYLIP 3.695 and FigTree v1.4.2. Furthermore, pathogenicity islands (PAIs) were predicted by the pathogenicity island database. Potential antibiotic resistance genes in MDR-SHH02 were predicted based on the information in the Antibiotic Resistance Genes Database (ARDB). MDR-SHH02 was found to be resistant to all of the tested antibiotics. The total draft genome length of MDR-SHH02 was 4,003,808 bp. There were 74.25% of coding sequences to be annotated into 21 of the Clusters of Orthologous Groups (COGs) of protein terms, such as 'transcription' and 'amino acid transport and metabolism'. Furthermore, there were 45 PAIs homologous to the sequence MDRSHH02000806. Additionally, a total of 12 gene sequences in MDR-SHH02 were highly similar to the sequences of antibiotic resistance genes in ARDB, including genes encoding aminoglycoside‑modifying enzymes [e.g., aac(3)-Ia, ant(2'')‑Ia, aph33ib and aph(3')-Ia], β-lactamase genes (bl2b_tem and bl2b_tem1), sulfonamide-resistant dihydropteroate synthase genes (sul1 and sul2), catb3 and tetb. These results suggest that numerous genes mediate resistance to various antibiotics in MDR-SHH02, and provide a clinical guidance for the personalized therapy of A. baumannii-infected patients.

  8. Soft rot decay capabilities and interactions of fungi and bacteria from fumigated utility poles

    International Nuclear Information System (INIS)

    Wang, C.J.K.; Worrall, J.J.

    1992-11-01

    The objectives were to (1) identify microfungi and bacterial associates isolated from fumigated southern pine poles from EPRI project RP 1471-72, (2) study the soft-rot capabilities of predominant fungi, and (3) study interactions among microorganisms in relation to wood decay. Methods for identification followed standard techniques using morphological and physiological criteria. Soft-rot by microfungi alone and with bacteria was determined as weight loss and anatomical examination of wood blocks using light microscopy and limited electron microscopy. Acinetobacter calcoaceticus was the predominant bacterium. Twenty-one species of microfungi were identified including four new species. A book entitled IDENTIFICATION MANUAL FOR FUNGI FROM UTILITY POLES IN THE EASTERN UNITED STATES was published. An improved soft-rot test was devised. Fifty-one of 84 species (60%) of microfungi from poles tested were soft-rot positive; that is much greater than previously reported. Three types of anatomical damage of wood of pine or birch caused by soft-rot fungi were described. Interaction tests showed that, in some cases, there was a strong synergism between bacteria and fungi in causing weight loss, but results were inconsistent. Although soft rot is often most apparent under conditions of very high moisture, intermediate moisture levels appear to be optimal, as with basidiomycete decayers

  9. Implication of human handling on packaged sausage rolls during sale

    Directory of Open Access Journals (Sweden)

    Coolborn AKHARAIYI FRED

    2016-08-01

    Full Text Available In other to identify the implication of human handling of packaged sausage rolls after production, a microbiological safety evaluation was carried out on sausage rolls sold on street and in shops. Among the sausage rolls, gala purchased from street vendors has the highest bacterial load of 2.82 × 104 CFU/g and 4.3 × 106 spore/g of fungal load, followed by meaty with bacterial load of 1.71 × 104 CFU/g and fungal load of 1.6 × 105 spore/g and was least in rite sausage roll with 1.46 × 104 CFU/g and 1 × 105 spore/g bacterial and fungal loads respectively. Seventeen bacteria species were isolated from both street vended and shop sold sausage rolls, the isolates identified including: Bacillus cereus, Acinetobacter calcoaceticus, Alcaligenes faecalis, Citrobacter freundii, Klebsiella ozaenae, Staphylococcus epidermidis, Enterobacter aerogenes, Staphylococcus aureus, Aeromonas hydrophila, Plesiomonas shigelloides, Moraxella catarhalis, Bacillus substilis, Escherichia coli, Salmonella typhi, Aeromonas anaerogenes, Aerococcus viridans and Azomonas agilis. Five fungi species were isolated from street vended sausage rolls only. The fungal species are Penicillium notatum, Aspergillus parasiticus, Aspergillus flavus, Penicillium italicum and Gliocephalis spp. From this study, street vended samples have higher microbial contamination than shop sold sausage rolls due to improper handling during sales.

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

    Science.gov (United States)

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

    2015-02-10

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

  11. Huellas digitales de cepas de Acinetobacter baumannii procedentes de pacientes hospitalizados en la Caja Petrolera de Salud de Obrajes, mediante el método de Pulsed Field Gel Electrophoresis (PFGE, La Paz, Bolivia. Marzo 2015

    Directory of Open Access Journals (Sweden)

    García-Rada Giovanni

    2017-08-01

    Full Text Available Acinetobacter baumannii, worldwide is considered an opportunistic microorganism, present in several cases of hospital-acquired infections. In the Caja Petrolera de Salud of Obrajes Hospital was made the isolation of four Acinetobacter baumannii strains. Identification was confirmed by biochemical tests. Then, the PFGE molecular technique was applied for the identification of genomic fingerprints using Apa I restriction en-zyme.

  12. Pan Drug-Resistant Environmental Isolate of Acinetobacter baumannii from Croatia.

    Science.gov (United States)

    Goic-Barisic, Ivana; Seruga Music, Martina; Kovacic, Ana; Tonkic, Marija; Hrenovic, Jasna

    2017-06-01

    Acinetobacter baumannii is an emerging nosocomial pathogen with also emerging resistance to different antibiotics. Multidrug and pan drug-resistant clinical isolates were reported worldwide. Here we report the first evidence of pan drug-resistant environmental isolate of A. baumannii. The isolate was recovered from the effluent of secondary treated municipal wastewater of the City of Zagreb, Croatia. The isolate was resistant to penicillins/β-lactamase inhibitors, carbapenems, fluoroquinolones, aminoglycosides, folate pathway inhibitors, and polymyxins, except intermediately susceptible to minocycline and tigecycline. Intrinsic chromosomally located bla OXA-51-like gene and acquired plasmid-located bla OXA-23-like gene were related to clinical isolates. Pan drug-resistant A. baumannii can occur in natural environments outside of the hospital. Secondary treated municipal wastewater represents a potential epidemiological reservoir of pan drug-resistant A. baumannii and carbapenem resistance gene.

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

    International Nuclear Information System (INIS)

    Allen, C. Leigh; Gulick, Andrew M.

    2014-01-01

    The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented. Microorganisms produce a variety of natural products via secondary metabolic biosynthetic pathways. Two of these types of synthetic systems, the nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), use large modular enzymes containing multiple catalytic domains in a single protein. These multidomain enzymes use an integrated carrier protein domain to transport the growing, covalently bound natural product to the neighboring catalytic domains for each step in the synthesis. Interestingly, some PKS and NRPS clusters contain free-standing domains that interact intermolecularly with other proteins. Being expressed outside the architecture of a multi-domain protein, these so-called type II proteins present challenges to understand the precise role they play. Additional structures of individual and multi-domain components of the NRPS enzymes will therefore provide a better understanding of the features that govern the domain interactions in these interesting enzyme systems. The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented here. Comparison with the closest structural homologs of other carrier proteins identifies the requirements for a conserved glycine residue and additional important sequence and structural requirements within the regions that interact with partner proteins

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

    Energy Technology Data Exchange (ETDEWEB)

    Allen, C. Leigh; Gulick, Andrew M., E-mail: gulick@hwi.buffalo.edu [University at Buffalo, Buffalo, NY 14203 (United States)

    2014-06-01

    The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented. Microorganisms produce a variety of natural products via secondary metabolic biosynthetic pathways. Two of these types of synthetic systems, the nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), use large modular enzymes containing multiple catalytic domains in a single protein. These multidomain enzymes use an integrated carrier protein domain to transport the growing, covalently bound natural product to the neighboring catalytic domains for each step in the synthesis. Interestingly, some PKS and NRPS clusters contain free-standing domains that interact intermolecularly with other proteins. Being expressed outside the architecture of a multi-domain protein, these so-called type II proteins present challenges to understand the precise role they play. Additional structures of individual and multi-domain components of the NRPS enzymes will therefore provide a better understanding of the features that govern the domain interactions in these interesting enzyme systems. The high-resolution crystal structure of a free-standing carrier protein from Acinetobacter baumannii that belongs to a larger NRPS-containing operon, encoded by the ABBFA-003406–ABBFA-003399 genes of A. baumannii strain AB307-0294, that has been implicated in A. baumannii motility, quorum sensing and biofilm formation, is presented here. Comparison with the closest structural homologs of other carrier proteins identifies the requirements for a conserved glycine residue and additional important sequence and structural requirements within the regions that interact with partner proteins.

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Infecção cutânea rara por Acinetobacter baumannii em imunocompetente: relato de um caso

    OpenAIRE

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

    2008-01-01

    O Acinetobacter baumanni é patógeno oportunista antigamente considerado de baixa virulência. Atualmente está envolvido em processos infecciosos que acometem pacientes imunocomprometidos,grandes queimados e pacientes em unidades de terapia intensiva que fazem uso de ventilação mecânica. Esse relato de caso chama atenção para infecção cutânea rara por essa bactéria em paciente imunocompetente.

  18. Post-surgical meningitis due to multiresistant Acinetobacter baumannii. Effective treatment with intravenous and/or intraventricular colistin and therapeutic dilemmas.

    Science.gov (United States)

    Paramythiotou, E; Karakitsos, D; Aggelopoulou, H; Sioutos, P; Samonis, G; Karabinis, A

    2007-02-01

    Post-surgical meningitis and/or ventriculitis caused by Gram-negative bacteria may be difficult to treat due to the emergence of multiresistant strains. Two patients with multiresistant Acinetobacter baumannii central nervous system infection, successfully treated with either intravenous and/or intraventricular colistin are presented. Unresolved issues such as dose and duration of intraventricular colistin are discussed.

  19. Draft Genome Sequences of Six Multidrug-Resistant Clinical Strains of Acinetobacter baumannii, Isolated at Two Major Hospitals in Kuwait.

    Science.gov (United States)

    Nasser, Kother; Mustafa, Abu Salim; Khan, Mohd Wasif; Purohit, Prashant; Al-Obaid, Inaam; Dhar, Rita; Al-Fouzan, Wadha

    2018-04-19

    Acinetobacter baumannii is an important opportunistic pathogen in global health care settings. Its dissemination and multidrug resistance pose an issue with treatment and outbreak control. Here, we present draft genome assemblies of six multidrug-resistant clinical strains of A. baumannii isolated from patients admitted to one of two major hospitals in Kuwait. Copyright © 2018 Nasser et al.

  20. Simultaneous identification of multiple β-lactamases in Acinetobacter baumannii in relation to carbapenem and ceftazidime resistance, using liquid chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Trip, H.; Mende, K.; Majchrzykiewicz-Koehorst, J.A.; Sedee, N.J.A.; Hulst, A.G.; Jansen, H.J.; Murray, C.K.; Paauw, A.

    2015-01-01

    Shotgun proteomics using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied to detect β-lactamases in clinical Acinetobacter baumannii isolates. The correlation of the detection of β-lactamase proteins (rather than PCR detection of the corresponding genes) with the resistance

  1. 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.

    Directory of Open Access Journals (Sweden)

    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.

  2. Identification of Acinetobacter baumannii of Human and Animal Origins by a Gene-Specific PCR.

    Science.gov (United States)

    Hamouda, Ahmed

    2017-09-01

    Acinetobacter baumannii is a notorious nosocomial pathogen known for its ability to cause severe infections, especially in intensive care units. The identification of a conserved gene encoding a hypothetical protein in A. baumannii isolates but not in other Acinetobacter species during a comparative genomic analysis was reported. For the purpose of this study, we call this gene, A.b_hyp gene. The aim of this study was to report the results of screening for the presence of the A.b_hyp gene in a worldwide collection of well-characterized A. baumannii collected from clinical and animal specimens. A total of 83 clinical, animal, and type strains were used. These comprised 73 A. baumannii isolates of clinical (n = 60) and animal origin (n = 13), and ten type strains, including a positive control strain, A. baumannii ATCC 19606. All isolates were examined by PCR amplification of the A.b_hyp gene. The A.b_hyp gene was detected in 72 isolates (99%) of A. baumannii but one clinical isolate failed to produce an amplicon. The control strain, A. baumannii ATCC 19606, was also positive for this gene. No bands were detected in non-A. baumannii species and therefore the isolates are thought to be negative for the gene. No bands were detected in non-A. baumannii isolates and therefore they are thought to be negative for the gene. The PCR A.b_ hyp method provides evidence that detection of this gene can be used as a reliable, easy, and low-cost biomarker for A. baumannii identification.

  3. Evaluation of bacterial growth inhibition by mercaptopropionic acid in metallo-β-lactamase detection on multidrug-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Mayer, Letícia Eichstaedt; Hörner, Rosmari; Tizotti, Maisa Kräulich; Martini, Rosiéli; Roehrs, Magda Cristina Souza Marques; Kempfer, Cláudia Barbisan

    2012-01-01

    Metallo-β-lactamase (MBL) has been reported all over the world. The inhibitory effect of mercaptopropionic acid (MPA) on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC) for multidrug-resistant Acinetobacter baumanni strains. MPA significantly inhibited growth of the strains. The use of MPA can affect the results in phenotypic methods of MBL detection.

  4. Structure determination of LpxA from the lipopolysaccharide-synthesis pathway of Acinetobacter baumannii

    International Nuclear Information System (INIS)

    Badger, John; Chie-Leon, Barbara; Logan, Cheyenne; Sridhar, Vandana; Sankaran, Banumathi; Zwart, Peter H.; Nienaber, Vicki

    2012-01-01

    Crystal structures of the LpxA protein from A. baumannii were solved in apo forms that were suitable for structure-based antibacterial drug discovery. Acinetobacter baumannii is a Gram-negative pathogenic bacterium which is resistant to most currently available antibiotics and that poses a significant health threat to hospital patients. LpxA is a key enzyme in the biosynthetic pathway of the lipopolysaccharides that are components of the bacterial outer membrane. It is a potential target for antibacterial agents that might be used to fight A. baumannii infections. This paper describes the structure determination of the apo form of LpxA in space groups P2 1 2 1 2 1 and P6 3 . These crystal forms contained three and one protein molecules in the asymmetric unit and diffracted to 1.8 and 1.4 Å resolution, respectively. A comparison of the conformations of the independent protein monomers within and between the two crystal asymmetric units revealed very little structural variation across this set of structures. In the P6 3 crystal form the enzymatic site is exposed and is available for the introduction of small molecules of the type used in fragment-based drug discovery and structure-based lead optimization

  5. Characterization of newly isolated lytic bacteriophages active against Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Maia Merabishvili

    Full Text Available Based on genotyping and host range, two newly isolated lytic bacteriophages, myovirus vB_AbaM_Acibel004 and podovirus vB_AbaP_Acibel007, active against Acinetobacter baumannii clinical strains, were selected from a new phage library for further characterization. The complete genomes of the two phages were analyzed. Both phages are characterized by broad host range and essential features of potential therapeutic phages, such as short latent period (27 and 21 min, respectively, high burst size (125 and 145, respectively, stability of activity in liquid culture and low frequency of occurrence of phage-resistant mutant bacterial cells. Genomic analysis showed that while Acibel004 represents a novel bacteriophage with resemblance to some unclassified Pseudomonas aeruginosa phages, Acibel007 belongs to the well-characterized genus of the Phikmvlikevirus. The newly isolated phages can serve as potential candidates for phage cocktails to control A. baumannii infections.

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

    Science.gov (United States)

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

    2013-04-01

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

  7. Characterization and Testing the Efficiency of Acinetobacter baumannii Phage vB-GEC_Ab-M-G7 as an Antibacterial Agent

    Directory of Open Access Journals (Sweden)

    Ia Kusradze

    2016-10-01

    Full Text Available Acinetobacter baumannii is a gram-negative, non-motile bacterium that, due to its multidrug resistance, has become a major nosocomial pathogen .The increasing number of multidrug resistant (MDR strains has renewed interest in phage therapy. The aim of our study was to assess the effectiveness of phage administration in Acinetobacter baumannii wound infections in an animal model to demonstrate phage therapy as non-toxic, safe and alternative antibacterial remedy. Using classical methods for the study of bacteriophage properties, we characterized phage vB-GEC_Ab-M-G7 as a dsDNA myovirus with a 90kb genome size. Important characteristics of vB-GEC_Ab-M-G7include a short latent period and large burst size, wide host range, resistance to chloroform and thermal and pH stability. In a rat wound model, phage application effectively decreased the number of bacteria isolated from the wounds of successfully treated animals. This study highlights the effectiveness of the phage therapy and provides further insight into treating infections caused by MDR strains using phage administration.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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...

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

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    Xinhua Fu

    2014-01-01

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

  11. Risk factors associated with multi-drug-resistant Acinetobacter baumannii nosocomial infections at a tertiary care hospital in Makkah, Saudi Arabia - a matched case–control study

    Science.gov (United States)

    Al-Gethamy, Manal M; Faidah, Hani S; Adetunji, Hamed Ademola; Ashgar, Sami S; Mohanned, Tayeb K; Mohammed, Al-Haj; Khurram, Muhammad; Hassali, Mohamed A

    2017-01-01

    Objective To determine risk factors for multi-drug-resistant Acinetobacter baumannii (MDR-AB) nosocomial infections in intensive care units in a tertiary care hospital, Makkah, Saudi Arabia. Methods We performed a hospital-based, matched case–control study in patients who were admitted to Al Noor Specialist Hospital between 1 January 2012 and 31 August 2012. The study included cases of A. baumannii nosocomial infection and controls without infection. Controls were matched to cases by age and ward of admission. Results The most frequent site of infection was the respiratory tract (77.3%). Susceptibility to antimicrobial MDR-AB was 92.0% for ceftazidime and ciprofloxacin, while it was 83.3% for imipenem, 83.0% for trimethoprim, 79.0% for amikacin, and 72.7% for gentamicin. Multiple logistic regression of risk factors showed that immunosuppression (OR = 2.9; 95% CI 1.5–5.6; p = 0.002), clinical outcome (OR = 0.4; 95% CI 0.3–0.9; p = 0.01), invasive procedures (OR = 7.9; 95% CI 1.8–34.2; p = 0.002), a central venous catheter (OR = 2.9; 95% CI 1.5–5.6; p = 0.000), and an endotracheal tube (OR = 3.4; 95% CI 1.6–7.3; p = 0.001) were associated with MDR-AB. Conclusions Acinetobacter nosocomial infections are associated with admission to the ICU (Intensive care unit) and exposure to invasive procedures. PMID:28480813

  12. Detection of OXA-Type Carbapenemase Genes in Acinetobacter baumannii Isolates from Nosocomial Infections in Isfahan Hospitals, Iran

    OpenAIRE

    Vajihe Karbasizade; Leila Heidari; Reyhaneh Jafari

    2016-01-01

    "> Background: Acinetobacter baumannii as one of the causes of nosocomial infections has becomeresistant to almost all antimicrobial agents. The emergence of resistance to carbapenems, one ofthe last drugs on the shelf, is the major concern about A. baumannii antimicrobial resistance.Resistance to carbapenems is mediated by production of class B and D carbapenemases. The aimof this study was to detect the resistance genes including blaOXA-23, 24, 51, and 58 in A. baumanniiisolates from nos...

  13. Clinical and Epidemiological Significance of Carbapenem Resistance in Acinetobacter baumannii Infections.

    Science.gov (United States)

    Tal-Jasper, Ruthy; Katz, David E; Amrami, Nadav; Ravid, Dor; Avivi, Dori; Zaidenstein, Ronit; Lazarovitch, Tsilia; Dadon, Mor; Kaye, Keith S; Marchaim, Dror

    2016-05-01

    Carbapenems are considered the treatment of choice for Acinetobacter baumannii infections. Many facilities implement preventive measures toward only carbapenem-resistant A. baumannii (CRAB). However, the independent role of the carbapenem resistance determinant on patient outcomes remains controversial. In a 6-year analysis of adults with A. baumannii bloodstream infection (BSI), the outcomes of 149 CRAB isolates were compared to those of 91 patients with carbapenem-susceptible A. baumannii In bivariable analyses, CRAB BSIs were significantly associated with worse outcomes and with a delay in the initiation of appropriate antimicrobial therapy (DAAT). However, in multivariable analyses, carbapenem resistance status was no longer associated with poor outcomes, while DAAT remained an independent predictor. The epidemiological significance of A. baumannii should not be determined by its resistance to carbapenems. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. Bactericidal activity of ciprofloxacin upon Escherichia coli and Acinetobacter baumanni.

    Science.gov (United States)

    Zemelman, R; Vejar, C; Bello, H; Domínguez, M; González, G

    1992-01-01

    The mechanisms of bactericidal activity of ciprofloxacin (mechanisms A and B) upon cells of a strain of Escherichia coli and one strain of Acinetobacter baumannii were investigated under different conditions. The killing of E. coli cells by ciprofloxacin was significantly reduced by chloramphenicol, but this antibiotic showed almost no activity upon killing of A. baumannii cells by this quinolone. Similar results were obtained when rifampicin was added to ciprofloxacin. Bactericidal activity of ciprofloxacin upon nondividing cells of E. coli was lower and that upon non-dividing cells of A. baumannii was not affected when compared with activity of ciprofloxacin upon dividing cells of both microorganisms. These results demonstrate that the antibacterial activity of ciprofloxacin upon A. baumannii is independent of protein and ARN synthesis, a fact which suggests that this quinolone exerts only bactericidal mechanism B upon A. baumannii. This finding might explain, at least in part, the lower susceptibility of this microorganism to ciprofloxacin.

  15. Comparative genomics of multidrug resistance in Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Pierre-Edouard Fournier

    2006-01-01

    Full Text Available Acinetobacter baumannii is a species of nonfermentative gram-negative bacteria commonly found in water and soil. This organism was susceptible to most antibiotics in the 1970s. It has now become a major cause of hospital-acquired infections worldwide due to its remarkable propensity to rapidly acquire resistance determinants to a wide range of antibacterial agents. Here we use a comparative genomic approach to identify the complete repertoire of resistance genes exhibited by the multidrug-resistant A. baumannii strain AYE, which is epidemic in France, as well as to investigate the mechanisms of their acquisition by comparison with the fully susceptible A. baumannii strain SDF, which is associated with human body lice. The assembly of the whole shotgun genome sequences of the strains AYE and SDF gave an estimated size of 3.9 and 3.2 Mb, respectively. A. baumannii strain AYE exhibits an 86-kb genomic region termed a resistance island--the largest identified to date--in which 45 resistance genes are clustered. At the homologous location, the SDF strain exhibits a 20 kb-genomic island flanked by transposases but devoid of resistance markers. Such a switching genomic structure might be a hotspot that could explain the rapid acquisition of resistance markers under antimicrobial pressure. Sequence similarity and phylogenetic analyses confirm that most of the resistance genes found in the A. baumannii strain AYE have been recently acquired from bacteria of the genera Pseudomonas, Salmonella, or Escherichia. This study also resulted in the discovery of 19 new putative resistance genes. Whole-genome sequencing appears to be a fast and efficient approach to the exhaustive identification of resistance genes in epidemic infectious agents of clinical significance.

  16. Comparative Genomics of Multidrug Resistance in Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available Acinetobacter baumannii is a species of nonfermentative gram-negative bacteria commonly found in water and soil. This organism was susceptible to most antibiotics in the 1970s. It has now become a major cause of hospital-acquired infections worldwide due to its remarkable propensity to rapidly acquire resistance determinants to a wide range of antibacterial agents. Here we use a comparative genomic approach to identify the complete repertoire of resistance genes exhibited by the multidrug-resistant A. baumannii strain AYE, which is epidemic in France, as well as to investigate the mechanisms of their acquisition by comparison with the fully susceptible A. baumannii strain SDF, which is associated with human body lice. The assembly of the whole shotgun genome sequences of the strains AYE and SDF gave an estimated size of 3.9 and 3.2 Mb, respectively. A. baumannii strain AYE exhibits an 86-kb genomic region termed a resistance island-the largest identified to date-in which 45 resistance genes are clustered. At the homologous location, the SDF strain exhibits a 20 kb-genomic island flanked by transposases but devoid of resistance markers. Such a switching genomic structure might be a hotspot that could explain the rapid acquisition of resistance markers under antimicrobial pressure. Sequence similarity and phylogenetic analyses confirm that most of the resistance genes found in the A. baumannii strain AYE have been recently acquired from bacteria of the genera Pseudomonas, Salmonella, or Escherichia. This study also resulted in the discovery of 19 new putative resistance genes. Whole-genome sequencing appears to be a fast and efficient approach to the exhaustive identification of resistance genes in epidemic infectious agents of clinical significance.

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

    Science.gov (United States)

    Pimchan, T; Maensiri, D; Eumkeb, G

    2017-10-01

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

  18. Investigation of colistin sensitivity via three different methods in Acinetobacter baumannii isolates with multiple antibiotic resistance.

    Science.gov (United States)

    Sinirtaş, Melda; Akalin, Halis; Gedikoğlu, Suna

    2009-09-01

    In recent years there has been an increase in life-threatening infections caused by Acinetobacter baumannii with multiple antibiotic resistance, which has lead to the use of polymyxins, especially colistin, being reconsidered. The aim of this study was to investigate the colistin sensitivity of A. baumannii isolates with multiple antibiotic resistance via different methods, and to evaluate the disk diffusion method for colistin against multi-resistant Acinetobacter isolates, in comparison to the E-test and Phoenix system. The study was carried out on 100 strains of A. baumannii (colonization or infection) isolated from the microbiological samples of different patients followed in the clinics and intensive care units of Uludağ University Medical School between the years 2004 and 2005. Strains were identified and characterized for their antibiotic sensitivity by Phoenix system (Becton Dickinson, Sparks, MD, USA). In all studied A. baumannii strains, susceptibility to colistin was determined to be 100% with the disk diffusion, E-test, and broth microdilution methods. Results of the E-test and broth microdilution method, which are accepted as reference methods, were found to be 100% consistent with the results of the disk diffusion tests; no very major or major error was identified upon comparison of the tests. The sensitivity and the positive predictive value of the disk diffusion method were found to be 100%. Colistin resistance in A. baumannii was not detected in our region, and disk diffusion method results are in accordance with those of E-test and broth microdilution methods.

  19. Evaluation of bacterial growth inhibition by mercaptopropionic acid in metallo-β-lactamase detection on multidrug-resistant Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Letícia Eichstaedt Mayer

    2012-04-01

    Full Text Available INTRODUCTION: Metallo-β-lactamase (MBL has been reported all over the world. METHODS: The inhibitory effect of mercaptopropionic acid (MPA on bacterial growth was evaluated by comparison between disk diffusion and broth dilution methodology with determination of the minimum inhibitory concentration (MIC for multidrug-resistant Acinetobacter baumanni strains. RESULTS: MPA significantly inhibited growth of the strains. CONCLUSIONS: The use of MPA can affect the results in phenotypic methods of MBL detection.

  20. Ecology and resistance of Moraxella-Acinetobacter

    International Nuclear Information System (INIS)

    Gulistani, A.W.

    1977-01-01

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

  1. A pyrroloquinolinequinone-dependent glucose dehydrogenase (PQQ-GDH)-electrode with direct electron transfer based on polyaniline modified carbon nanotubes for biofuel cell application

    International Nuclear Information System (INIS)

    Schubart, Ivo W.; Göbel, Gero; Lisdat, Fred

    2012-01-01

    Graphical abstract: - Abstract: In this study we present a pyrroloquinolinequinone-dependent glucose dehydrogenase [(PQQ)-GDH] electrode with direct electron transfer between the enzyme and electrode. Soluble pyrroloquinolinequinone-dependent glucose dehydrogenase from Acinetobacter calcoaceticus is covalently bound to an electropolymerized polyaniline copolymer film on a multi-walled carbon nanotube (MWCNT)-modified gold electrode. The pulsed electropolymerization of 2-methoxyaniline-5-sulfonic acid (MASA) and m-aminobenzoic acid (ABA) is optimized with respect to the efficiency of the bioelectrocatalytic conversion of glucose. The glucose oxidation starts at −0.1 V vs. Ag/AgCl and current densities up to 500 μA/cm 2 at low potential of +0.1 V vs. Ag/AgCl can be achieved. The electrode shows a glucose sensitivity in the range from 0.1 mM to 5 mM at a potential of +0.1 V vs. Ag/Ag/Cl. The dynamic range is extended to 100 mM at +0.4 V vs. Ag/AgCl. The electron transfer mechanism is studied and buffer effects are investigated. The developed enzyme electrode is examined for bioenergetic application by assembling of a membrane-less biofuel cell. For the cathode a bilirubin oxidase (BOD) based MWCNT-modified gold electrode with direct electron transfer (DET) is used. The biofuel cell exhibits a cell potential of 680 ± 20 mV and a maximum power density of up to 65 μW/cm 2 at 350 mV vs. Ag/AgCl.

  2. Community-acquired carbapenem-resistant Acinetobacter baumannii urinary tract infection just after marriage in a renal transplant recipient.

    Science.gov (United States)

    Solak, Y; Atalay, H; Turkmen, K; Biyik, Z; Genc, N; Yeksan, M

    2011-12-01

    Urinary tract infection (UTI) is common in renal transplant recipients and may worsen allograft and patient survival. Many risk factors such as age, female gender, immunosuppression, comorbidity, deceased-donor kidney transplantation, and uretheral catheterization are involved in development of UTI. Acinetobacter baumannii has rarely been reported as a causative agent for development of UTI. Here, we present an unusual case of a renal transplant recipient who developed community-acquired carbapenem-resistent A. baumannii UTI. © 2011 John Wiley & Sons A/S.

  3. Changes in antimicrobial resistance of clinical isolates of Acinetobacter baumannii group isolated in Greece, 2010-2015.

    Science.gov (United States)

    Dafopoulou, K; Tsakris, A; Pournaras, S

    2018-04-01

    In recent years, hospitals in southeastern Europe have faced dramatically high rates of antibiotic-resistant Acinetobacter baumannii. We analysed the evolution of resistance among clinical isolates of A. baumannii group obtained from nine tertiary hospitals throughout Greece over 6 years (2010-2015). Identification and antimicrobial susceptibility testing were performed using Vitek 2 or Microscan walkaway automated systems. Between 2010 and 2015, resistance to ampicillin/sulbactam increased from 46.2 to 88.2 % (P=0.021), resistance to gentamicin increased from 69.3 to 86.4 % (P=0.014) and resistance to tobramycin increased from 59.8 to 76.8 % (P=0.011). Imipenem resistance rates were consistently very high, ranging from 90.3 % in 2010 to 94.5 % in 2015 (P=0.198), while meropenem resistance rates increased from 82.6 % in 2010 to 94.8 % in 2015 (P=0.006). Resistance rates to trimethoprim/sulfamethoxazole showed a remarkable decreasing trend, declining from 90.2 % in 2010 to 69.1 % in 2015 (P=0.035). These evolutions render the treatment of A. baumannii infections particularly challenging and underline the need for enhanced infection control measures.

  4. The Genetic Analysis of an Acinetobacter johnsonii Clinical Strain Evidenced the Presence of Horizontal Genetic Transfer.

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    Sabrina Montaña

    Full Text Available Acinetobacter johnsonii rarely causes human infections. While most A. johnsonii isolates are susceptible to virtually all antibiotics, strains harboring a variety of β-lactamases have recently been described. An A. johnsonii Aj2199 clinical strain recovered from a hospital in Buenos Aires produces PER-2 and OXA-58. We decided to delve into its genome by obtaining the whole genome sequence of the Aj2199 strain. Genome comparison studies on Aj2199 revealed 240 unique genes and a close relation to strain WJ10621, isolated from the urine of a patient in China. Genomic analysis showed evidence of horizontal genetic transfer (HGT events. Forty-five insertion sequences and two intact prophages were found in addition to several resistance determinants such as blaPER-2, blaOXA-58, blaTEM-1, strA, strB, ereA, sul1, aacC2 and a new variant of blaOXA-211, called blaOXA-498. In particular, blaPER-2 and blaTEM-1 are present within the typical contexts previously described in the Enterobacteriaceae family. These results suggest that A. johnsonii actively acquires exogenous DNA from other bacterial species and concomitantly becomes a reservoir of resistance genes.

  5. Endemic Acinetobacter baumannii in a New York hospital.

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    Scott A Weisenberg

    Full Text Available Acinetobacter baumannii is an increasingly multidrug-resistant (MDR cause of hospital-acquired infections, often associated with limited therapeutic options. We investigated A. baumannii isolates at a New York hospital to characterize genetic relatedness.Thirty A. baumannii isolates from geographically-dispersed nursing units within the hospital were studied. Isolate relatedness was assessed by repetitive sequence polymerase chain reaction (rep-PCR. The presence and characteristics of integrons were assessed by PCR. Metabolomic profiles of a subset of a prevalent strain isolates and sporadic isolates were characterized and compared.We detected a hospital-wide group of closely related carbapenem resistant MDR A. baumannii isolates. Compared with sporadic isolates, the prevalent strain isolates were more likely to be MDR (p = 0.001. Isolates from the prevalent strain carried a novel Class I integron sequence. Metabolomic profiles of selected prevalent strain isolates and sporadic isolates were similar.The A. baumannii population at our hospital represents a prevalent strain of related MDR isolates that contain a novel integron cassette. Prevalent strain and sporadic isolates did not segregate by metabolomic profiles. Further study of environmental, host, and bacterial factors associated with the persistence of prevalent endemic A. baumannii strains is needed to develop effective prevention strategies.

  6. Design, Synthesis, and Crystal Structures of 6-Alkylidene-2 -Substituted Penicillanic Acid Sulfones as Potent Inhibitors of Acinetobacter baumannii OXA-24 Carbapenemase

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    Bou, G.; Santillana, E; Sheri, A; Beceiro, A; Sampson, J; Kalp, M; Bethel, C; Distler, A; Drawz, S; et. al.

    2010-01-01

    Class D {beta}-lactamases represent a growing and diverse class of penicillin-inactivating enzymes that are usually resistant to commercial {beta}-lactamase inhibitors. As many such enzymes are found in multi-drug resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa, novel {beta}-lactamase inhibitors are urgently needed. Five unique 6-alkylidene-2{prime}-substituted penicillanic acid sulfones (1-5) were synthesized and tested against OXA-24, a clinically important {beta}-lactamase that inactivates carbapenems and is found in A. baumannii. Based upon the roles Tyr112 and Met223 play in the OXA-24 {beta}-lactamase, we also engineered two variants (Tyr112Ala and Tyr112Ala,Met223Ala) to test the hypothesis that the hydrophobic tunnel formed by these residues influences inhibitor recognition. IC{sub 50} values against OXA-24 and two OXA-24 {beta}-lactamase variants ranged from 10 {+-} 1 (4 vs WT) to 338 {+-} 20 nM (5 vs Tyr112Ala, Met223Ala). Compound 4 possessed the lowest K{sub i} (500 {+-} 80 nM vs WT), and 1 possessed the highest inactivation efficiency (k{sub inact}/K{sub i} = 0.21 {+-} 0.02 {micro}M{sup -1}s{sup -1}). Electrospray ionization mass spectrometry revealed a single covalent adduct, suggesting the formation of an acyl-enzyme intermediate. X-ray structures of OXA-24 complexed to four inhibitors (2.0-2.6 {angstrom}) reveal the formation of stable bicyclic aromatic intermediates with their carbonyl oxygen in the oxyanion hole. These data provide the first structural evidence that 6-alkylidene-2{prime}-substituted penicillin sulfones are effective mechanism-based inactivators of class D {beta}-lactamases. Their unique chemistry makes them developmental candidates. Mechanisms for class D hydrolysis and inhibition are discussed, and a pathway for the evolution of the BlaR1 sensor of Staphylococcus aureus to the class D {beta}-lactamases is proposed.

  7. Isolation and characterization of novel chitinolytic bacteria

    Science.gov (United States)

    Gürkök, Sümeyra; Görmez, Arzu

    2016-04-01

    Chitin, a linear polymer of β-1,4-N-acetylglucosamine units, is one of the most abundant biopolymers widely distributed in the marine and terrestrial environments. It is found as a structural component of insects, crustaceans and the cell walls of fungi. Chitinases, the enzymes degrading chitin by cleaving the β-(1-4) bond, have gained increased attention due to their wide range of biotechnological applications, especially for biocontrol of harmful insects and phytopathogenic fungi in agriculture. In the present study, 200 bacterial isolates from Western Anatolia Region of Turkey were screened for chitinolytic activity on agar media amended with colloidal chitin. Based on the chitin hydrolysis zone, 13 isolates were selected for further study. Bacterial isolates with the highest chitinase activity were identified as Acinetobacter calcoaceticus, Arthrobacter oxydans, Bacillus cereus, Bacillus megaterium, Brevibacillus reuszeri, Kocuria erythromyxa, Kocuria rosea, Novosphingobium capsulatum, Rhodococcus bratislaviensis, Rhodococcus fascians and Staphylococcus cohnii by MIS and BIOLOG systems. The next aims of the study are to compare the productivity of these bacteria quantitatively, to purify the enzyme from the most potent producer and to apply the pure enzyme for the fight against the phytopathogenic fungi and harmful insects.

  8. Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

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    Neyser De La Torre-Ruiz

    Full Text Available ABSTRACT The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA, solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (p < 0.05 on plant growth and the sugar content of A. americana, showing that these native plant growth-promoting bacteria are a practical, simple, and efficient alternative to promote the growth of agave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species.

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

    Science.gov (United States)

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

    2016-01-01

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

  10. Complete genome analysis of three Acinetobacter baumannii clinical isolates in China for insight into the diversification of drug resistance elements.

    Science.gov (United States)

    Zhu, Lingxiang; Yan, Zhongqiang; Zhang, Zhaojun; Zhou, Qiming; Zhou, Jinchun; Wakeland, Edward K; Fang, Xiangdong; Xuan, Zhenyu; Shen, Dingxia; Li, Quan-Zhen

    2013-01-01

    The emergence and rapid spreading of multidrug-resistant Acinetobacter baumannii strains has become a major health threat worldwide. To better understand the genetic recombination related with the acquisition of drug-resistant elements during bacterial infection, we performed complete genome analysis on three newly isolated multidrug-resistant A. baumannii strains from Beijing using next-generation sequencing technology. Whole genome comparison revealed that all 3 strains share some common drug resistant elements including carbapenem-resistant bla OXA-23 and tetracycline (tet) resistance islands, but the genome structures are diversified among strains. Various genomic islands intersperse on the genome with transposons and insertions, reflecting the recombination flexibility during the acquisition of the resistant elements. The blood-isolated BJAB07104 and ascites-isolated BJAB0868 exhibit high similarity on their genome structure with most of the global clone II strains, suggesting these two strains belong to the dominant outbreak strains prevalent worldwide. A large resistance island (RI) of about 121-kb, carrying a cluster of resistance-related genes, was inserted into the ATPase gene on BJAB07104 and BJAB0868 genomes. A 78-kb insertion element carrying tra-locus and bla OXA-23 island, can be either inserted into one of the tniB gene in the 121-kb RI on the chromosome, or transformed to conjugative plasmid in the two BJAB strains. The third strains of this study, BJAB0715, which was isolated from spinal fluid, exhibit much more divergence compared with above two strains. It harbors multiple drug-resistance elements including a truncated AbaR-22-like RI on its genome. One of the unique features of this strain is that it carries both bla OXA-23 and bla OXA-58 genes on its genome. Besides, an Acinetobacter lwoffii adeABC efflux element was found inserted into the ATPase position in BJAB0715. Our comparative analysis on currently completed Acinetobacter baumannii

  11. Complete genome analysis of three Acinetobacter baumannii clinical isolates in China for insight into the diversification of drug resistance elements.

    Directory of Open Access Journals (Sweden)

    Lingxiang Zhu

    Full Text Available The emergence and rapid spreading of multidrug-resistant Acinetobacter baumannii strains has become a major health threat worldwide. To better understand the genetic recombination related with the acquisition of drug-resistant elements during bacterial infection, we performed complete genome analysis on three newly isolated multidrug-resistant A. baumannii strains from Beijing using next-generation sequencing technology.Whole genome comparison revealed that all 3 strains share some common drug resistant elements including carbapenem-resistant bla OXA-23 and tetracycline (tet resistance islands, but the genome structures are diversified among strains. Various genomic islands intersperse on the genome with transposons and insertions, reflecting the recombination flexibility during the acquisition of the resistant elements. The blood-isolated BJAB07104 and ascites-isolated BJAB0868 exhibit high similarity on their genome structure with most of the global clone II strains, suggesting these two strains belong to the dominant outbreak strains prevalent worldwide. A large resistance island (RI of about 121-kb, carrying a cluster of resistance-related genes, was inserted into the ATPase gene on BJAB07104 and BJAB0868 genomes. A 78-kb insertion element carrying tra-locus and bla OXA-23 island, can be either inserted into one of the tniB gene in the 121-kb RI on the chromosome, or transformed to conjugative plasmid in the two BJAB strains. The third strains of this study, BJAB0715, which was isolated from spinal fluid, exhibit much more divergence compared with above two strains. It harbors multiple drug-resistance elements including a truncated AbaR-22-like RI on its genome. One of the unique features of this strain is that it carries both bla OXA-23 and bla OXA-58 genes on its genome. Besides, an Acinetobacter lwoffii adeABC efflux element was found inserted into the ATPase position in BJAB0715.Our comparative analysis on currently completed

  12. Reduction in chlorhexidine efficacy against multi-drug-resistant Acinetobacter baumannii international clone II.

    Science.gov (United States)

    Hayashi, M; Kawamura, K; Matsui, M; Suzuki, M; Suzuki, S; Shibayama, K; Arakawa, Y

    2017-03-01

    Nosocomial infections caused by Acinetobacter baumannii international clone II (IC II) can cause severe clinical outcomes. Differential evaluation of bactericidal efficacy of chlorhexidine gluconate (CHX) and benzethonium chloride (BZT) disinfectants against IC II and non-IC II isolates. Minimum inhibitory concentrations (MICs) of CHX and BZT were determined for 137 A. baumannii IC II, 99 non-IC II and 69 non-baumannii isolates, further classified according to MIC values into disinfectant-reduced susceptible (DRS) and disinfectant-susceptible (DS) groups. Time-kill curves and minimum bactericidal concentrations (MBCs) were evaluated for representative isolates in each group. CHX and BZT MIC 90 s for IC II isolates were 100 and 175mg/L, respectively, but those for non-IC II and non-baumannii isolates were <100mg/L. Nevertheless, time-kill curves indicated that CHX and BZT reduced live bacterial cell number by 5 log 10 for IC II and non-IC II isolates within 30s when used at 1000mg/L, comparable to practical use concentrations. CHX MBC at 30s was 1000mg/L for IC II and non-IC II isolates, and was not influenced by addition of 3% bovine serum albumin (BSA); BZT MBC at 30s was 100mg/L without BSA and increased up to 500mg/L upon addition of BSA. No significant differences in BSA were found between DRS and DS isolates. CHX and BZT were effective against Acinetobacter spp. including IC II at a concentration of 1000mg/L and exposure for at least 30s, but their concentrations should be considered carefully to ensure sufficient effects in both clinical and healthcare settings. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  13. Impact of ertapenem on antimicrobial resistance in a sentinel group of Gram-negative bacilli: a 6 year antimicrobial resistance surveillance study.

    Science.gov (United States)

    Rodriguez-Osorio, Carlos A; Sanchez-Martinez, Cesar O; Araujo-Melendez, Javier; Criollo, Elia; Macias-Hernandez, Alejandro E; Ponce-de-Leon, Alfredo; Ponce-de-Leon, Sergio; Sifuentes-Osornio, Jose

    2015-03-01

    To determine the association between ertapenem and resistance of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii-calcoaceticus complex to different antimicrobials while adjusting for relevant hospital factors. This was a retrospective time-series study conducted at a tertiary care centre from September 2002 to August 2008. The specific impact of ertapenem on the resistance of these Gram-negative bacilli (GNB) was assessed by multiple linear regression analysis, adjusting for the average length of stay, rate of hospital-acquired infections and use of 10 other antimicrobials, including type 2 carbapenems. Unadjusted analyses revealed significant increases over the duration of the study in the number of GNB resistant to meropenem/imipenem among 1000 isolates each of E. coli (0.46 ± 0.22, P  0.05) with changes in resistance for any pathogen/antimicrobial combination. After controlling for confounders, ertapenem was not associated with changes in resistance in a group of sentinel GNB, although significant variations in resistance to different antimicrobials were observed in the unadjusted analyses. These results emphasize the importance of implementation of local resistance surveillance platforms and stewardship programmes to combat the global emergence and spread of antimicrobial resistance. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

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

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    Li Jian

    2011-04-01

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

  15. Spread of imipenem-resistant Acinetobacter baumannii co-expressing OXA-23 and GES-11 carbapenemases in Lebanon.

    Science.gov (United States)

    Hammoudi, D; Moubareck, C Ayoub; Hakime, N; Houmani, M; Barakat, A; Najjar, Z; Suleiman, M; Fayad, N; Sarraf, R; Sarkis, D Karam

    2015-07-01

    The acquisition of carbapenemases by Acinetobacter baumannii is reported increasingly worldwide, but data from Lebanon are limited. The aims of this study were to evaluate the prevalence of imipenem-resistant A. baumannii in Lebanon, identify resistance determinants, and detect clonal relatedness. Imipenem-resistant A. baumannii were collected from nine Lebanese hospitals during 2012. Antimicrobial susceptibility, the cloxacillin effect, and ethylenediaminetetraacetic acid (EDTA) synergy were determined. Genes encoding carbapenemases and insertion sequence ISAba1 were screened via PCR sequencing. ISAba1 position relative to genes encoding Acinetobacter-derived cephalosporinases (ADCs) and OXA-23 was studied by PCR mapping. Clonal linkage was examined by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Out of 724 A. baumannii isolated in 2012, 638 (88%) were imipenem-resistant. Of these, 142 were analyzed. Clavulanic acid-imipenem synergy suggested carbapenem-hydrolyzing extended-spectrum β-lactamase. A positive cloxacillin test indicated ADCs, while EDTA detection strips were negative. Genotyping indicated that 90% of isolates co-harbored blaOXA-23 and blaGES-11. The remaining strains had blaOXA-23, blaOXA-24, blaGES-11, or blaOXA-24 with blaGES-11. ISAba1 was located upstream of blaADC and blaOXA-23 in 97% and 100% of isolates, respectively. ERIC-PCR fingerprinting revealed 18 pulsotypes spread via horizontal gene transfer and clonal dissemination. This survey established baseline evidence of OXA-23 and GES-11-producing A. baumannii in Lebanon, indicating the need for further surveillance. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. [Nosocomial infection/colonization of the respiratory tract caused by Acinetobacter baumannii in an Internal Medicine ward].

    Science.gov (United States)

    Salas Coronas, J; Cabezas Fernández, T; Alvarez-Ossorio García de Soria, R; Rogado González, M C; Delgado Fernández, M; Díez García, F

    2002-10-01

    To present the epidemiology of the outbreak and the description of patients with infection or colonization of the respiratory tract caused by A. baumannii in an Internal Medicine ward. 20 consecutively patients hospitalized in the Internal Medicine ward were studied during 18 months with isolation of multiresistant A. baumanni in respiratory tract specimens with or without clinical signs of infection. Starting on an index case, that was a patient coming from other hospital with diagnosis of nosocomial Acinetobacter pneumonia, we detected 20 patients. The age of the patients ranged from 48 to 95 years, with a mean of 71.4 years. Eighty percent were males. The clinical features were similar: advanced age, with chronic diseases (35 percent diabetics, 45 percent with chronic lung diseases), and use of broad-spectrum antibiotics agents, fundamentally third generation cephalosporin (70 percent), clarithromycin (55 percent) and quinolones (30 percent). 75 percent of patients were in the same ward. Eight (40 percent) of the patients with chronic lung diseases were subjects with COPD, two with asthma and chronic glucocorticoids treatment, and one with a sleep apnea. In four cases the isolation was considered a colonization. The mean stay was 26.15 days, and the mortality 40 percent. The nosocomial infection caused by Acinetobacter baumannii is responsible of a high morbi-mortality between the patients hospitalized in an Internal Medicine ward, and produce an increase in length of stay. It is necessary a combination of control measures to prevent the transmission in the hospital and the outbreak of new multiresistant strains.

  17. Crystallization and preliminary X-ray analysis of the reductase component of p-hydroxyphenylacetate 3-hydroxylase from Acinetobacter baumannii

    International Nuclear Information System (INIS)

    Oonanant, Worrapoj; Sucharitakul, Jeerus; Chaiyen, Pimchai; Yuvaniyama, Jirundon

    2012-01-01

    The reductase component of p-hydroxyphenylacetate 3-hydroxylase from A. baumannii was overexpressed, purified and crystallized. X-ray diffraction data were collected and processed to 2.3 Å resolution. p-Hydroxyphenylacetate 3-hydroxylase (HPAH) from Acinetobacter baumannii catalyzes the hydroxylation of p-hydroxyphenylacetate (HPA) at the ortho position to yield 3,4-dihydroxyphenylacetate (DHPA). HPAH from A. baumannii is a two-component flavoprotein consisting of a smaller reductase (C 1 ) component and a larger oxygenase (C 2 ) component. The C 1 component supplies a reduced flavin in its free form to the C 2 counterpart for hydroxylation. In addition, HPA can bind to C 1 and enhance the flavin-reduction rate without becoming hydroxylated. The recombinant C 1 component was purified and crystallized using the microbatch method at 295 K. X-ray diffraction data were collected to 2.3 Å resolution using synchrotron radiation on the BL13B1 beamline at NSRRC, Taiwan. The crystal belonged to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 47.78, b = 59.92, c = 211.85 Å, and contained two molecules of C 1 per asymmetric unit

  18. Succinate, iron chelation, and monovalent cations affect the transformation efficiency of Acinetobacter baylyi ATCC 33305 during growth in complex media.

    Science.gov (United States)

    Leong, Colleen G; Boyd, Caroline M; Roush, Kaleb S; Tenente, Ricardo; Lang, Kristine M; Lostroh, C Phoebe

    2017-10-01

    Natural transformation is the acquisition of new genetic material via the uptake of exogenous DNA by competent bacteria. Acinetobacter baylyi is model for natural transformation. Here we focus on the natural transformation of A. baylyi ATCC 33305 grown in complex media and seek environmental conditions that appreciably affect transformation efficiency. We find that the transformation efficiency for A. baylyi is a resilient characteristic that remains high under most conditions tested. We do find several distinct conditions that alter natural transformation efficiency including addition of succinate, Fe 2+ (ferrous) iron chelation, and substitution of sodium ions with potassium ones. These distinct conditions could be useful to fine tune transformation efficiency for researchers using A. baylyi as a model organism to study natural transformation.

  19. Is the use of low-pressure pulsatile lavage for pressure ulcer management associated with environmental contamination with Acinetobacter baumannii?

    Science.gov (United States)

    Ho, Chester H; Johnson, Tova; Miklacic, Joan; Donskey, Curtis J

    2009-10-01

    Ho CH, Johnson T, Miklacic J, Donskey CJ. Is the use of low-pressure pulsatile lavage for pressure ulcer management associated with environmental contamination with Acinetobacter baumannii? To determine the extent of environmental contamination associated with low-pressure pulsatile lavage of stage III or IV pressure ulcers in patients with spinal cord injury (SCI) when routine infection control precautions are used for wounds colonized or infected with Acinetobacter baumannii. Prospective investigation in which pressure ulcer cultures and environmental cultures were obtained before and after low-pressure pulsatile lavage treatment, and before and after regular dressing changes. Environmental cultures included the patient's bedrail and settle plates placed 0.6, 1.5, and 2.4m from the wound to assess airborne spread of A. baumannii. SCI inpatient unit in a Department of Veterans Affairs Medical Center. Inpatients (N=15) with SCI receiving daily low-pressure pulsatile lavage treatment for stage III or IV pressure ulcers with standard dressing change, as well as regular dressing changes without low-pressure pulsatile lavage at other times of the day. Standard, regular dressing changes and dressing changes with low-pressure pulsatile lavage. Comparison of frequency of environmental contamination with A. baumannii associated with low-pressure pulsatile lavage versus regular dressing changes. Of the 15 SCI inpatients meeting inclusion criteria, 9 (60%) grew A. baumannii from their wounds. Of the 9 patients with wound cultures positive for A. baumannii, only 1 (11%) had environmental contamination with this organism after performance of low-pressure pulsatile lavage, and the same patient had environmental contamination after a standard dressing change. The antibiotic susceptibility patterns of the wound and environmental A. baumannii isolates were identical. Low-pressure pulsatile lavage using the infection control methods described is not associated with an increased

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

    International Nuclear Information System (INIS)

    Zakaria, Zainul Akmar; Zakaria, Zainoha; Surif, Salmijah; Ahmad, Wan Azlina

    2007-01-01

    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 -1 of Cr(VI) was reduced at a flow rate of 8.0 mL min -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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Effects of Group 1 versus Group 2 carbapenems on the susceptibility of Acinetobacter baumannii to carbapenems: a before and after intervention study of carbapenem-use stewardship.

    Science.gov (United States)

    Yoon, Young Kyung; Yang, Kyung Sook; Lee, Seung Eun; Kim, Hyun Jeong; Sohn, Jang Wook; Kim, Min Ja

    2014-01-01

    Antimicrobial stewardship programs have been proposed for reducing bacterial resistance in the hospital environment. The purpose of this study was to investigate the impact of a carbapenem-use stewardship program on the susceptibility of Acinetobacter baumannii to Group 2 carbapenems. A before and after intervention study was conducted at a university hospital from September 2008 to February 2013. Three study periods were defined: Phase I, pre-intervention (months 1-18); Phase II, a postintervention period during which ertapenem use was mandated but carbapenem use was not restricted (months 19-36); and Phase III, a postintervention period during which Group 2 carbapenem use was restricted (months 37-54). During the study period, intervention resulted in diminished consumption of Group 2 carbapenems (antimicrobial use density (AUD): 21.3±6.0 in Phase I, 18.8±6.0 in Phase II, 16.1±4.4 in Phase III; P = 0.028) and increased consumption of ertapenem (AUD: 2.7±1.7 in Phase I, 7.2±4.5 in Phase II, 9.1±5.3 in Phase III; Pcarbapenem during the previous one month was positively and significantly associated with a subsequent increase in the proportion of carbapenem-resistant A. baumannii (CRAB) (P = 0.031). Implementing a carbapenem-use stewardship program featuring the preferential use of ertapenem for treating appropriate indications of infection resulted in reduced use of Group 2 carbapenems and had a positive impact on the susceptibility of A. baumannii to carbapenems. This approach could be integrated into CRAB-control strategies in hospitals.

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

    Directory of Open Access Journals (Sweden)

    Amornrat Intorasoot

    2017-06-01

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

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

    Directory of Open Access Journals (Sweden)

    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

  5. RNA-Mediated cis Regulation in Acinetobacter baumannii Modulates Stress-Induced Phenotypic Variation.

    Science.gov (United States)

    Ching, Carly; Gozzi, Kevin; Heinemann, Björn; Chai, Yunrong; Godoy, Veronica G

    2017-06-01

    In the nosocomial opportunistic pathogen Acinetobacter baumannii , RecA-dependent mutagenesis, which causes antibiotic resistance acquisition, is linked to the DNA damage response (DDR). Notably, unlike the Escherichia coli paradigm, recA and DDR gene expression in A. baumannii is bimodal. Namely, there is phenotypic variation upon DNA damage, which may provide a bet-hedging strategy for survival. Thus, understanding recA gene regulation is key to elucidate the yet unknown DDR regulation in A. baumannii Here, we identify a structured 5' untranslated region (UTR) in the recA transcript which serves as a cis -regulatory element. We show that a predicted stem-loop structure in this 5' UTR affects mRNA half-life and underlies bimodal gene expression and thus phenotypic variation in response to ciprofloxacin treatment. We furthermore show that the stem-loop structure of the recA 5' UTR influences intracellular RecA protein levels and, in vivo , impairing the formation of the stem-loop structure of the recA 5' UTR lowers cell survival of UV treatment and decreases rifampin resistance acquisition from DNA damage-induced mutagenesis. We hypothesize that the 5' UTR allows for stable recA transcripts during stress, including antibiotic treatment, enabling cells to maintain suitable RecA levels for survival. This innovative strategy to regulate the DDR in A. baumannii may contribute to its success as a pathogen. IMPORTANCE Acinetobacter baumannii is an opportunistic pathogen quickly gaining antibiotic resistances. Mutagenesis and antibiotic resistance acquisition are linked to the DNA damage response (DDR). However, how the DDR is regulated in A. baumannii remains unknown, since unlike most bacteria, A. baumannii does not follow the regulation of the Escherichia coli paradigm. In this study, we have started to uncover the mechanisms regulating the novel A. baumannii DDR. We have found that a cis -acting 5' UTR regulates recA transcript stability, RecA protein levels, and DNA

  6. Transposons and integrons in colistin-resistant clones of Klebsiella pneumoniae and Acinetobacter baumannii with epidemic or sporadic behaviour.

    Science.gov (United States)

    Arduino, Sonia M; Quiroga, María Paula; Ramírez, María Soledad; Merkier, Andrea Karina; Errecalde, Laura; Di Martino, Ana; Smayevsky, Jorgelina; Kaufman, Sara; Centrón, Daniela

    2012-10-01

    Multiple transposons, integrons and carbapenemases were found in Klebsiella pneumoniae colistin-resistant isolates as well as a genomic resistance island of the AbaR type in Acinetobacter baumannii colistin-resistant isolates from different hospitals from Buenos Aires City. PFGE analysis showed a polyclonal dissemination of antimicrobial resistance mechanisms among K. pneumoniae isolates, while in A. baumannii isolates the epidemic clone 1 from South America was found. Resistance determinants associated with horizontal gene transfer are contributing to the evolution to pandrug resistance in both epidemic and sporadic clones.

  7. Overexpression, purification, crystallization and preliminary X-ray crystallographic analysis of the periplasmic domain of outer membrane protein A from Acinetobacter baumannii

    International Nuclear Information System (INIS)

    Park, Jeong Soon; Lee, Woo Cheol; Choi, Saehae; Yeo, Kwon Joo; Song, Jung Hyun; Han, Young-Hyun; Lee, Je Chul; Kim, Seung Il; Jeon, Young Ho; Cheong, Chaejoon; Kim, Hye-Yeon

    2011-01-01

    The crystallization of the OmpA periplasmic domain from A. baumannii is described. Outer membrane protein A from Acinetobacter baumannii (AbOmpA) is a major outer membrane protein and a key player in the bacterial pathogenesis that induces host cell death. AbOmpA is presumed to consist of an N-terminal β-barrel transmembrane domain and a C-terminal periplasmic OmpA-like domain. In this study, the recombinant C-terminal periplasmic domain of AbOmpA was overexpressed in Escherichia coli, purified and crystallized using the vapour-diffusion method. A native diffraction data set was collected to a resolution of 2.0 Å using synchrotron radiation. The space group of the crystal was P2 1 , with unit-cell parameters a = 58.24, b = 98.59, c = 97.96 Å, β = 105.92°. The native crystal contained seven or eight molecules per asymmetric unit and had a calculated Matthews coefficient of 2.93 or 2.56 Å 3 Da −1

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

    Science.gov (United States)

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

    2016-12-01

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

  9. INDeGenIUS, a new method for high-throughput identification of ...

    Indian Academy of Sciences (India)

    . 1. 0. 0. 3. Acinetobacter baumannii AB307. 2. 0. 0. 0. 0. 0. 2. Acinetobacter baumannii ACICU. 0. 0. 0. 0. 0. 0. 0. Acinetobacter baumannii ATCC. 0. 0. 0. 0. 0. 0. 0. Acinetobacter baumannii AYE. 2. 0. 1. 0. 0. 0. 3. Acinetobacter baumannii SDF.

  10. Biology of Acinetobacter baumannii: Pathogenesis, Antibiotic Resistance Mechanisms, and Prospective Treatment Options

    Science.gov (United States)

    Lee, Chang-Ro; Lee, Jung Hun; Park, Moonhee; Park, Kwang Seung; Bae, Il Kwon; Kim, Young Bae; Cha, Chang-Jun; Jeong, Byeong Chul; Lee, Sang Hee

    2017-01-01

    Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospital-acquired nosocomial infections in the modern healthcare system. Due to the prevalence of infections and outbreaks caused by multi-drug resistant A. baumannii, few antibiotics are effective for treating infections caused by this pathogen. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of A. baumannii is important. In this review, we summarize current studies on the virulence factors that contribute to A. baumannii pathogenesis, including porins, capsular polysaccharides, lipopolysaccharides, phospholipases, outer membrane vesicles, metal acquisition systems, and protein secretion systems. Mechanisms of antibiotic resistance of this organism, including acquirement of β-lactamases, up-regulation of multidrug efflux pumps, modification of aminoglycosides, permeability defects, and alteration of target sites, are also discussed. Lastly, novel prospective treatment options for infections caused by multi-drug resistant A. baumannii are summarized. PMID:28348979

  11. Heterologous expression of pyrroloquinoline quinone (pqq) gene cluster confers mineral phosphate solubilization ability to Herbaspirillum seropedicae Z67.

    Science.gov (United States)

    Wagh, Jitendra; Shah, Sonal; Bhandari, Praveena; Archana, G; Kumar, G Naresh

    2014-06-01

    Gluconic acid secretion mediated by the direct oxidation of glucose by pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase (GDH) is responsible for mineral phosphate solubilization in Gram-negative bacteria. Herbaspirillum seropedicae Z67 (ATCC 35892) genome encodes GDH apoprotein but lacks genes for the biosynthesis of its cofactor PQQ. In this study, pqqE of Erwinia herbicola (in plasmid pJNK1) and pqq gene clusters of Pseudomonas fluorescens B16 (pOK53) and Acinetobacter calcoaceticus (pSS2) were over-expressed in H. seropedicae Z67. Transformants Hs (pSS2) and Hs (pOK53) secreted micromolar levels of PQQ and attained high GDH activity leading to secretion of 33.46 mM gluconic acid when grown on 50 mM glucose while Hs (pJNK1) was ineffective. Hs (pJNK1) failed to solubilize rock phosphate, while Hs (pSS2) and Hs (pOK53) liberated 125.47 μM and 168.07 μM P, respectively, in minimal medium containing 50 mM glucose under aerobic conditions. Moreover, under N-free minimal medium, Hs (pSS2) and Hs (pOK53) not only released significant P but also showed enhanced growth, biofilm formation, and exopolysaccharide (EPS) secretion. However, indole acetic acid (IAA) production was suppressed. Thus, the addition of the pqq gene cluster, but not pqqE alone, is sufficient for engineering phosphate solubilization in H. seropedicae Z67 without compromising growth under nitrogen-fixing conditions.

  12. Response to Bile Salts in Clinical Strains of Acinetobacter baumannii Lacking the AdeABC Efflux Pump: Virulence Associated with Quorum Sensing

    OpenAIRE

    L?pez, Maria; Blasco, Lucia; Gato, Eva; Perez, Astrid; Fern?ndez-Garcia, Laura; Mart?nez-Martinez, Luis; Fern?ndez-Cuenca, Felipe; Rodr?guez-Ba?o, Jes?s; Pascual, Alvaro; Bou, German; Tom?s, Maria

    2017-01-01

    Introduction: Acinetobacter baumannii is an opportunistic nosocomial pathogen associated with multiple infections. This pathogen usually colonizes (first stage of microbial infection) host tissues that are in contact with the external environment. As one of the sites of entry in human hosts is the gastrointestinal tract, the pathogen must be capable of tolerating bile salts. However, studies analyzing the molecular characteristics involved in the response to bile salts in clinical strains of ...

  13. Insertion sequence transposition determines imipenem resistance in Acinetobacter baumannii.

    Science.gov (United States)

    Kuo, Han-Yueh; Chang, Kai-Chih; Liu, Chih-Chin; Tang, Chuan Yi; Peng, Jhih-Hua; Lu, Chia-Wei; Tu, Chi-Chao; Liou, Ming-Li

    2014-10-01

    This study employed genomewide analysis to investigate potential resistance mechanisms in Acinetobacter baumannii following imipenem exposure. Imipenem-selected mutants were generated from the imipenem-susceptible strain ATCC 17978 by multistep selection resistance. Antibiotic susceptibilities were examined, and the selected mutants originated from the ATCC 17978 strain were confirmed by pulsed-field gel electrophoresis. The genomic sequence of a resistant mutant was analyzed using a next-generation sequencing platform, and genetic recombination was further confirmed by PCR. The result showed that phenotypic resistance was observed with carbapenem upon exposure to various concentrations of imipenem. Genomewide analysis showed that ISAba1 transposition was initiated by imipenem exposure at concentrations up to 0.5 mg/L. Transposition of ISAba1 upstream of blaOXA-95 was detected in all the selected mutants. The expression of blaOXA-95 was further analyzed by quantitative PCR, and the results demonstrated that a 200-fold increase in gene expression was required for resistance to imipenem. This study concluded that imipenem exposure at a concentration of 0.5 mg/L mediated the transposition of ISAba1 upstream of the blaOXA-95 gene and resulted in the overexpression of blaOXA-95 gene, which may play a major role in the resistance to imipenem in A. baumannii.

  14. Antimicrobial resistance in Acinetobacter baumannii: From bench to bedside

    Science.gov (United States)

    Lin, Ming-Feng; Lan, Chung-Yu

    2014-01-01

    Acinetobacter baumannii (A. baumannii) is undoubtedly one of the most successful pathogens in the modern healthcare system. With invasive procedures, antibiotic use and immunocompromised hosts increasing in recent years, A. baumannii has become endemic in hospitals due to its versatile genetic machinery, which allows it to quickly evolve resistance factors, and to its remarkable ability to tolerate harsh environments. Infections and outbreaks caused by multidrug-resistant A. baumannii (MDRAB) are prevalent and have been reported worldwide over the past twenty or more years. To address this problem effectively, knowledge of species identification, typing methods, clinical manifestations, risk factors, and virulence factors is essential. The global epidemiology of MDRAB is monitored by persistent surveillance programs. Because few effective antibiotics are available, clinicians often face serious challenges when treating patients with MDRAB. Therefore, a deep understanding of the resistance mechanisms used by MDRAB can shed light on two possible strategies to combat the dissemination of antimicrobial resistance: stringent infection control and antibiotic treatments, of which colistin-based combination therapy is the mainstream strategy. However, due to the current unsatisfying therapeutic outcomes, there is a great need to develop and evaluate the efficacy of new antibiotics and to understand the role of other potential alternatives, such as antimicrobial peptides, in the treatment of MDRAB infections. PMID:25516853

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

    Science.gov (United States)

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

    2017-01-01

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

  16. Etiología de la infección del sitio quirúrgico en pacientes egresados del Hospital Clinicoquirúrgico Docente "Joaquín Albarrán" Enero a marzo del 2000

    Directory of Open Access Journals (Sweden)

    Linet Alemán Mondeja

    2001-12-01

    Full Text Available Se reporta que las infecciones del sitio quirúrgico (ISQ constituyen formas frecuentes de infecciones nosocomiales, las cuales se originan por múltiples gérmenes (bacterias, virus, hongos. Se pretende mostrar la etiología de la ISQ de pacientes atendidos en el Hospital Clinicoquirúrgico Docente "Joaquín Albarrán" en el período de enero a marzo del 2000, cuando se observó una elevación de estas infecciones. Se realiza un estudio de serie de casos de ISQ, reportados por el sistema local de vigilancia de infecciones nosocomiales, del cual se obtuvieron sus características generales, de los procederes quirúrgicos realizados y la causa de dichas infecciones. De los casos presentados se les realizaron estudios microbiológicos a 31 pacientes y 61 aislamientos de gérmenes. El 9,6 % de ellos falleció y el 61,9 % tuvo que ser reintervenido por complicaciones quirúrgicas. Los factores de riesgo más frecuentes en los pacientes fueron la ancianidad (42,8 % y el hábito de fumar (47,6 %, anemia y alcoholismo en el 19 % de los casos respectivamente. Klebsiella pneumoniae (26,2 %, Pseudomonas aeruginosa (21,3 %, Escherichia coli (19,7 %, Acinetobacter calcoaceticus (9,8 % y Staphylococcus aureus (8,2 %, fueron los gérmenes más detectados; todos mostraron niveles elevados de resistencia a los antibióticos disponibles. Se evidenció que los casos reportados fueron pacientes con alto riesgo de adquirir ISQ, y éstas fueron producidas básicamente por gérmenes gramnegativos multirresistentes a los antibióticos. Se requiere una evaluación preoperatoria del riesgo de adquirir ISQ, y la implementación de medidas de prevención y control de eficacia demostrada para estas infecciones.It is reported that surgical site infections (SSI are frequent forms of nosocomial infections, which are originated by multiple germs (bacteria, viruses, fungi. It is intended to show the etiology of SSI among patients attended at "Joaquin Albarrán" Clinical and

  17. Complete genome sequence of Acinetobacter baumannii XH386 (ST208, a multi-drug resistant bacteria isolated from pediatric hospital in China

    Directory of Open Access Journals (Sweden)

    Youhong Fang

    2016-03-01

    Full Text Available Acinetobacter baumannii is an important bacterium that emerged as a significant nosocomial pathogen worldwide. The rise of A. baumannii was due to its multi-drug resistance (MDR, while it was difficult to treat multi-drug resistant A. baumannii with antibiotics, especially in pediatric patients for the therapeutic options with antibiotics were quite limited in pediatric patients. A. baumannii ST208 was identified as predominant sequence type of carbapenem resistant A. baumannii in the United States and China. As we knew, there was no complete genome sequence reproted for A. baumannii ST208, although several whole genome shotgun sequences had been reported. Here, we sequenced the 4087-kilobase (kb chromosome and 112-kb plasmid of A. baumannii XH386 (ST208, which was isolated from a pediatric hospital in China. The genome of A. baumannii XH386 contained 3968 protein-coding genes and 94 RNA-only encoding genes. Genomic analysis and Minimum inhibitory concentration assay showed that A. baumannii XH386 was multi-drug resistant strain, which showed resistance to most of antibiotics, except for tigecycline. The data may be accessed via the GenBank accession number CP010779 and CP010780. Keywords: Acinetobacter baumannii, Multi-drug resistance, Paediatric

  18. Correlation Between ISAba1 Upstream ampC Gene and Resistance to Cefotaxime in Acinetobacter baumannii: A Serious Threat to Nosocomial Infections

    Directory of Open Access Journals (Sweden)

    Rezaee

    2016-01-01

    Full Text Available Background Infections due to Acinetobacter baumannii have become a significant challenge in modern healthcare systems. The global upsurge of multidrug resistance in A. baumannii has created widespread problems in the treatment of patients. Objectives We examined the prevalence ISAmpC and its correlation with cefotaxime resistance. Materials and Methods Standard biochemical tests were used to identify isolates. Genomic species of the genus Acinetobacter were confirmed by Amplified Ribosomal DNA Restriction Analysis (ARDRA. The susceptibility of 50 A. baumannii isolates to a variety of antimicrobial agents was determined using the disk diffusion method and E-test strips. PCR was used to investigate the connection of insertion sequences and the ampC gene. Clonal relatedness was determined by Repetitive Extragenic Palindromic PCR. Results ISAba1 located upstream of blaampC was found in 24 (48% of the A. baumannii isolates. In all of the studied isolates that had ISAmpC, the MIC for cefotaxime was 64 - 256 μg/mL. Based on the REP-PCR patterns among the resistant isolates, the highest number of ISAmpC positive isolates belonged to type B (n = 19 and type C (n = 12. Conclusions ISAba1 has become an important factor in A. baumannii’s resistance to cefotaxime.

  19. Response to Bile Salts in Clinical Strains of Acinetobacter baumannii Lacking the AdeABC Efflux Pump: Virulence Associated with Quorum Sensing

    OpenAIRE

    Maria López; Maria López; Lucia Blasco; Eva Gato; Eva Gato; Astrid Perez; Astrid Perez; Laura Fernández-Garcia; Laura Fernández-Garcia; Luis Martínez-Martinez; Luis Martínez-Martinez; Luis Martínez-Martinez; Felipe Fernández-Cuenca; Felipe Fernández-Cuenca; Felipe Fernández-Cuenca

    2017-01-01

    Introduction:Acinetobacter baumannii is an opportunistic nosocomial pathogen associated with multiple infections. This pathogen usually colonizes (first stage of microbial infection) host tissues that are in contact with the external environment. As one of the sites of entry in human hosts is the gastrointestinal tract, the pathogen must be capable of tolerating bile salts. However, studies analyzing the molecular characteristics involved in the response to bile salts in clinical strains of A...

  20. Identification of a new geographically widespread multiresistant Acinetobacter baumannii clone from European hospitals.

    Science.gov (United States)

    van Dessel, Helke; Dijkshoorn, Lenie; van der Reijden, Tanny; Bakker, Nancy; Paauw, Armand; van den Broek, Peterhans; Verhoef, Jan; Brisse, Sylvain

    2004-03-01

    The aim of the study was to investigate the genetic diversity of Acinetobacter baumannii clinical strains that had previously been allocated to three major groups based on automated ribotyping. Forty-seven isolates from European hospitals and one isolate from a South African hospital, geographically representative of the three ribogroups (ribogroups 1, 2 and 3 with 10, 23 and 15 isolates, respectively), were analysed using the highly discriminatory fingerprinting methods AFLP and pulsed-field gel electrophoresis (PFGE). Based on AFLP data, the isolates clustered into three main groups, each corresponding to one ribogroup. Inclusion of reference strains of the previously described clones I and II, responsible for outbreaks in northwestern European hospitals, showed that ribogroups 1 and 2 correspond to clones I and II, respectively, whereas ribogroup 3 apparently represents a new clone. This clone III was found in France, The Netherlands, Italy and Spain. Clones I and II were not limited to northwestern European countries, as they were also recovered from Spain, South Africa, Poland and Italy (clone I) and from Spain, Portugal, South Africa, France, Greece and Turkey (clone II). Combined AFLP and PFGE data showed intraclonal diversity and led to the distinction of 23 different genotypes. Three genotypes, two of them belonging to clone II and one to clone III, were found in different hospitals and may correspond to subsets of isolates with a more recent clonal relationship, which emphasizes the epidemic potential of these organisms.

  1. Identification and characteristics of imipenem-resistant Acinetobacter baumannii in surgical wards in a Chinese university hospital.

    Science.gov (United States)

    Wang, Dalin; Ma, Linlin; Wu, Zhenyu; Li, Mingcheng; Li, Xiaohan; Zhang, Wei; Chen, Kun

    2015-03-01

    The aim of this study was to investigate the prevalence and characteristics of imipenem-resistant Acinetobacter baumanni isolated from surgical wards in a university hospital, China. A total of 143 non-duplicate A. baumannii were isolated from 517 inpatients in surgery intensive care units (ICUs), burn wards, and general surgery wards. Of these, 102 isolates of A. baumannii (71.3%) were resistant to imipenem. Among imipenem-resistant isolates, all isolates were resistant to almost all antimicrobial agents except polymyxin E, all isolates were positive for blaOXA-23 and blaOXA-51 in addition to ISAba1, 52 (51%) were positive for blaOXA-58, 8 (7.8%) contained blaVIM-2, which co-harbored with blaOXA-58. Molecular typing revealed the presence of three clones among imipenem-resistant isolates. This study confirmed that A. baumannii strains harboring OXA or VIM type β-lactamases are widely distributed throughout the surgery wards. The data demonstrate that there was a high prevalence of imipenem-resistant A. baumannii infection in the region.

  2. Characterization of resistance mechanisms and genetic relatedness of carbapenem-resistant Acinetobacter baumannii isolated from blood, Italy.

    Science.gov (United States)

    Migliavacca, Roberta; Espinal, Paula; Principe, Luigi; Drago, Monica; Fugazza, Giulia; Roca, Ignasi; Nucleo, Elisabetta; Bracco, Silvia; Vila, Jordi; Pagani, Laura; Luzzaro, Francesco

    2013-02-01

    The aim of this study was to characterize the resistance mechanisms and genetic relatedness of 21 carbapenem-resistant Acinetobacter baumannii blood isolates collected in Italy during a 1-year multicenter prospective surveillance study. Genes coding for carbapenemase production were identified by polymerase chain reaction (PCR) and sequencing. Pulsed-field gel electrophoresis (PFGE), multiplex PCRs for group identification, and multilocus sequence typing (MLST) were used to determine genetic relationships. Carbapenem resistance was consistently related to the production of oxacillinases, mostly the plasmid-mediated OXA-58 enzyme. Strains producing the OXA-23 enzyme (chromosomally mediated) were also detected. Seven PFGE clones were identified, some of which being related to international (ICL- I and ICL-II) or national clonal lineages. Multiplex PCRs identified 4 different groups (group 2 being dominant), further distinguishable in 6 sequence types by MLST. The heterogeneity of profiles highlights the diffusion of international and national clonal lineages in Italy. Continuous surveillance is needed for monitoring the spread of these worrisome strains equipped with multiple drug resistance mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Controlling endemic multidrug-resistant Acinetobacter baumannii in Intensive Care Units using antimicrobial stewardship and infection control.

    Science.gov (United States)

    Cheon, Shinhye; Kim, Mi-Ja; Yun, Seon-Jin; Moon, Jae Young; Kim, Yeon-Sook

    2016-03-01

    Nosocomial infections caused by multidrug-resistant (MDR) Acinetobacter baumannii have become public-health problem. However, few studies have evaluated the control of endemic MDR A. baumannii in Intensive Care Units (ICUs). Therefore, we investigated the effectiveness of antimicrobial stewardship and comprehensive intensified infection control measures for controlling endemic MDR A. baumannii in ICUs at a tertiary care center. Carbapenem use was strictly restricted through antimicrobial stewardship. Environmental cleaning and disinfection was performed at least 3 times per day in addition to basic infection control measures. Isolation using plastic curtains and contact precautions were applied to patients who were colonized or infected with MDR A. baumannii. The outcome was measured as the incidence density rate of hospital-onset MDR A. baumannii among patients in the ICUs. The incidence density rate of hospital-onset MDR A. baumannii decreased from 22.82 cases per 1,000 patient-days to 2.68 cases per 1,000 patient-days after the interventions were implemented (odds ratio, 0.12; 95% confidence interval, 0.03 to 0.4; p baumannii in our ICUs within 1 year.

  4. Acinetobacter baumannii: Evolution of Antimicrobial Resistance—Treatment Options

    Science.gov (United States)

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

    2015-01-01

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

  5. Formation of interfacial network structure via photo-crosslinking in carbon fiber/epoxy composites

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    S. H. Deng

    2014-07-01

    Full Text Available A series of diblock copolymers (poly(n-butylacrylate-co-poly(2-hydroxyethyl acrylate-b-poly(glycidyl methacrylate ((PnBA-co-PHEA-b-PGMA, containing a random copolymer block PnBA-co-PHEA, were successfully synthesized by atom transfer radical polymerization (ATRP. After being chemically grafted onto carbon fibers, the photosensitive methacrylic groups were introduced into the random copolymer, giving a series of copolymers (poly(n-butylacrylate-co-poly(2-methacryloyloxyethyl acrylate-b-poly(glycidyl methacrylate((PnBA-co-PMEA-b-PGMA. Dynamic mechanical analysis indicated that the random copolymer block after ultraviolet (UV irradiation was a lightly crosslinked polymer and acted as an elastomer, forming a photo-crosslinked network structure at the interface of carbon fiber/epoxy composites. Microbond test showed that such an interfacial network structure greatly improved the cohesive strength and effectively controlled the deformation ability of the flexible interlayer. Furthermore, three kinds of interfacial network structures, i physical crosslinking by H-bonds, ii chemical crosslinking by photopolymerization, and iii interpenetrating crosslinked network by photopolymerization and epoxy curing reaction were received in carbon fiber/epoxy composite, depending on the various preparation processes.

  6. [Prevention of an outbreak of Acinetobacter baumannii in intensive care units: study of the efficacy of different mathematical methods].

    Science.gov (United States)

    Fresnadillo-Martínez, María José; García-Merino, Enrique; García-Sánchez, Enrique; Martín-del Rey, Ángel; Rodríguez-Encinas, Ángel; Rodríguez-Sánchez, Gerardo; García-Sánchez, José Elías

    2015-02-01

    Although in past decades, Acinetobacter baumanni infections have been sporadically identified in hospitals, nowadays the nosocomial infections due to this pathogen have notably increased. Its importance is due to its multidrug- resistance, morbidity and mortatility in healthcare settings. Consequently, it is important to predict the evolution of these outbreaks in order to stablish the most efficient control measures. There are several experimental studies shown that the compliance with hand and environmental hygiene and the efficient management of the healthcare work help to control the evolution of these outbreaks. The goal of this work is to formally proof these experimental results by means of the analysis of the results provided by the model. A stochastic mathematical model based on cellular automata was developed. The variables and parameters involved in it have been identified from the knowledge of the epidemiology and main characteristics of Acinetobacter infections. The model provides several simulations from different initial conditions. The analysis of these results proofs in a formal way that the compliance with hand and environmental hygiene and an efficient plannification of the work of healtcare workers yield a decrease in the colonized patients. Moreover, this is the unique model proposed studying the dynamics of an outbreak of A. baumanni. The computational implementation of the model provides us an efficient tool in the management of outbreaks due to A. baumanni. The analysis of the simulations obtained allows us to obtain a formal proof of the behaviour of the measures for control and prevention.

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

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    Ma Ling

    2009-10-01

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

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

    Science.gov (United States)

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

    2013-09-01

    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-drug resistant Acinetobacter baumannii isolated from the patients in Surgical Intensive Care Units (SICUs) of Pakistan Institute of Medical Sciences (PIMS), Islamabad, Pakistan. A total of 91 A. baumanni isolates were collected from PIMS during the period from February 2011 to December 2011. The antibiotic susceptibility testing was performed by standard disc diffusion method as recommended by CLSI. Combination disc method, Modified Hodge test, EDTA disc synergy test and AmpC disc test were performed for detection of ESBLs, carbapenemases, metallo β-lactamases, and AmpC β-lactamases, respectively. The prevalence of MDRs was reported 100% among A. baumannii. The antibiotic susceptibility profile showed that minocycline and tigecycline were the most effective drugs against A. baumannii. Almost all of A. baumannii isolates were carbapenemase and metallo β-lactamase producers. AmpC prevalence was observed in 41.76%, while none of the isolates was ESBL producer. Antibiogram and minimal inhibitory concentrations (MICs) indicated tetracycline is relatively effective against A. baumanii. Increased frequency of multi-drug resistance supports the need for continuous surveillance to determine prevalence and evolution of these enzymes in Pakistan.

  9. Whole-Cell Biocatalytic Synthesis of Cinnamyl Acetate with a Novel Esterase from the DNA Library of Acinetobacter hemolyticus.

    Science.gov (United States)

    Dong, Hao; Secundo, Francesco; Xue, Changhu; Mao, Xiangzhao

    2017-03-15

    Cinnamyl acetate has a wide application in the flavor and fragrance industry because of its sweet, balsamic, and floral odor. Up to now, lipases have been mainly used in enzyme-mediated synthesis of cinnamyl acetate, whereas esterases are used in only a few cases. Moreover, the use of purified enzymes is often a disadvantage, which leads to increases of the production costs. In this paper, a genomic DNA library of Acinetobacter hemolyticus was constructed, and a novel esterase (EstK1) was identified. After expression in Escherichia coli, the whole-cell catalyst of EstK1 displayed high transesterification activity to produce cinnamyl acetate in nonaqueous systems. Furthermore, under optimal conditions (vinyl acetate as acyl donor, isooctane as solvent, molar ratio 1:4, temperature 40 °C), the conversion ratio of cinnamyl alcohol could be up to 94.1% at 1 h, and it reached an even higher level (97.1%) at 2 h.

  10. Effects of Group 1 versus Group 2 carbapenems on the susceptibility of Acinetobacter baumannii to carbapenems: a before and after intervention study of carbapenem-use stewardship.

    Directory of Open Access Journals (Sweden)

    Young Kyung Yoon

    Full Text Available OBJECTIVE: Antimicrobial stewardship programs have been proposed for reducing bacterial resistance in the hospital environment. The purpose of this study was to investigate the impact of a carbapenem-use stewardship program on the susceptibility of Acinetobacter baumannii to Group 2 carbapenems. METHODS: A before and after intervention study was conducted at a university hospital from September 2008 to February 2013. Three study periods were defined: Phase I, pre-intervention (months 1-18; Phase II, a postintervention period during which ertapenem use was mandated but carbapenem use was not restricted (months 19-36; and Phase III, a postintervention period during which Group 2 carbapenem use was restricted (months 37-54. RESULTS: During the study period, intervention resulted in diminished consumption of Group 2 carbapenems (antimicrobial use density (AUD: 21.3±6.0 in Phase I, 18.8±6.0 in Phase II, 16.1±4.4 in Phase III; P = 0.028 and increased consumption of ertapenem (AUD: 2.7±1.7 in Phase I, 7.2±4.5 in Phase II, 9.1±5.3 in Phase III; P<0.001. The use of autoregressive-error models showed that in contrast with ertapenem use, the use of Group 2 carbapenem during the previous one month was positively and significantly associated with a subsequent increase in the proportion of carbapenem-resistant A. baumannii (CRAB (P = 0.031. CONCLUSIONS: Implementing a carbapenem-use stewardship program featuring the preferential use of ertapenem for treating appropriate indications of infection resulted in reduced use of Group 2 carbapenems and had a positive impact on the susceptibility of A. baumannii to carbapenems. This approach could be integrated into CRAB-control strategies in hospitals.

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

    Science.gov (United States)

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

    2018-05-01

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

  12. Caracterización fenotípica de aislamientos de Acinetobacter baumannii en una institución de salud de alta complejidad de Cali

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    Alfredo Prado

    2014-04-01

    Full Text Available Introducción. La caracterización fenotípica de las bacterias del género Acinetobacter mediante pruebas bioquímicas y microscópicas es posible. Varios estudios han demostrado que los aislamientos provenientes de infecciones asociadas a la atención en salud presentan una elevada resistencia a los antibióticos de primera elección. Objetivo. Describir los patrones de resistencia de los aislamientos de Acinetobacter baumannii obtenidos en una institución de salud, así como sus características fenotípicas y los posibles mecanismos de resistencia. Materiales y métodos. Se realizó un estudio descriptivo de corte transversal con 28 informes de muestras tomadas a pacientes hospitalizados con infección por A. baumannii. Las pruebas de sensibilidad para ceftazidime, cefepime, meropenem, amikacina y ciprofloxacina se realizaron con el sistema automatizado Vitek® y la clasificación de sensible, intermedia y resistente se hizo con base en el protocolo establecido por el Clinical and Laboratory Standards Institute para el año 2007. Resultados. El mayor porcentaje de aislamientos correspondió al sexo masculino (53,6 %, a la sala de infectología (28,5 % y al mes de septiembre (21,4 %; el tipo de muestra más frecuente fue el de secreción endotraqueal (53,6 %. A partir de los patrones de los perfiles de sensibilidad a los antibióticos empleados se obtuvieron 13 filotipos. Conclusión. Acinetobacter baumannii es un agente patógeno resistente a múltiples antimicrobianos, involucrado en brotes de infecciones asociadas a la atención en salud. Los patrones de los perfiles de resistencia permiten inferir que los posibles mecanismos de resistencia presentes en la mayoría de los aislamientos son la producción de betalactamasas de espectro extendido, las enzimas modificadoras del antibiótico y la modificación del sitio diana.

  13. Successful control of 2 simultaneous outbreaks of OXA-48 carbapenemase-producing Enterobacteriaceae and multidrug-resistant Acinetobacter baumannii in an intensive care unit.

    Science.gov (United States)

    Robustillo-Rodela, A; Pérez-Blanco, V; Espinel Ruiz, M A; Ruiz Carrascoso, G; Figueira Iglesias, J C; Abad Martín, D

    2017-12-01

    This report describes a double outbreak of OXA-48-producing Enterobacteriaceae (OXA-48-PE) and multidrug-resistant Acinetobacter baumannii (MRAB) in an intensive care unit (ICU) and the effectiveness of measures implemented, including decontamination with vaporized hydrogen peroxide (VHP). Affected patients were isolated in a confined area and cared for by dedicated personnel. Four percent chlorhexidine soap was used for patient daily hygiene. All patients are subjected to contact precautions. An in-depth cleaning of the ICU was performed with a chlorine solution, followed by decontamination with VHP. Environmental samples were taken before and after the decontamination. From July-October 2015, 13 patients were colonized or infected by OXA-48-PE and 18 by MRAB in the ICU. The cumulative incidence of OXA-48-PE and MRAB was 3.48% and 4.81%, respectively. In the period after the intervention, they were 0.8% and 0%, respectively (P control of outbreaks caused by microorganisms of high environmental impact. The rapid effect after the VHP treatment suggests an influence of this measure in eradication. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  14. Análisis genómico del resistoma de la cepa de Acinetobacter baumannii ABIBUN 107m multi-resistente y persistente en hospitales colombianos

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    Maria Teresa Reguero

    2014-07-01

    Full Text Available Título en español: Análisis genómico del resistoma de la cepa  de  Acinetobacter baumannii  ABIBUN 107m multi-resistente  y persistente  en hospitales colombianos Título en ingles: Genomic analysis of the resistoma of the strain of Acinetobacter baumannii ABIBUN 107m multi-resistant and persistent in Colombian hospitals Título corto: Análisis genómico del resistoma de la cepa  de  Acinetobacter baumannii  Resumen: Acinetobacter baumannii es una bacteria, causante de infecciones asociadas a la atención en salud como neumonía, septicemia, meningitis e infecciones urinarias entre otras. Se caracteriza por su capacidad para desarrollar y acumular rápidamente una gran variedad de mecanismos de resistencia a antibióticos. En esta investigación se realizó el análisis genómico de una cepa de A. baumannii ABIBUN 107m que forma parte de un clon persistente en hospitales colombianos, resistente a los antibióticos carbapenémicos (imipenem y meropenem,  antibióticos de elección en el tratamiento  infecciones causadas por este microorganismo. El genoma de esta bacteria fue secuenciado utilizando técnicas de alto rendimiento, ensamblado y anotado, obteniéndose un genoma constituido por  3954000 pb con 56 contigs;  consta de 4256 genes con un tamaño promedio de 912 pb;  3796 CDS  de los cuales por anotación 2884  se asignaron a COG; 57 tRNA y un porcentaje de GC de 38,74%. A. baumannii ABIBUN 107m es resistente a b-lactámicos, aminoglicósidos, quinolonas, tetraciclina, sulfonamida y colistina. En su genoma se localizaron genes asociados con el perfil de resistencia ya que presenta serin b-lactamasas (blaADC-38, blaOXA-64, blaOXA-23, blaampC-like,  blaamp(H-like, metalo b-lactamasa_B;  proteínas de unión a  penicilina de elevada masa molecular, secuencias de inserción tipo ISAba1; mutaciones en los genes de DNA girasa  y topoisomerasa IV subunidad A (gyrA y parC; enzimas modificadoras de aminoglicósidos (aph

  15. Structure of a short-chain dehydrogenase/reductase (SDR) within a genomic island from a clinical strain of Acinetobacter baumannii

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Bhumika S., E-mail: bhumika.shah@mq.edu.au; Tetu, Sasha G. [Macquarie University, Research Park Drive, Sydney, NSW 2109 (Australia); Harrop, Stephen J. [University of New South Wales, Sydney, NSW 2052 (Australia); Paulsen, Ian T.; Mabbutt, Bridget C. [Macquarie University, Research Park Drive, Sydney, NSW 2109 (Australia)

    2014-09-25

    The structure of a short-chain dehydrogenase encoded within genomic islands of A. baumannii strains has been solved to 2.4 Å resolution. This classical SDR incorporates a flexible helical subdomain. The NADP-binding site and catalytic side chains are identified. Over 15% of the genome of an Australian clinical isolate of Acinetobacter baumannii occurs within genomic islands. An uncharacterized protein encoded within one island feature common to this and other International Clone II strains has been studied by X-ray crystallography. The 2.4 Å resolution structure of SDR-WM99c reveals it to be a new member of the classical short-chain dehydrogenase/reductase (SDR) superfamily. The enzyme contains a nucleotide-binding domain and, like many other SDRs, is tetrameric in form. The active site contains a catalytic tetrad (Asn117, Ser146, Tyr159 and Lys163) and water molecules occupying the presumed NADP cofactor-binding pocket. An adjacent cleft is capped by a relatively mobile helical subdomain, which is well positioned to control substrate access.

  16. Structure of a short-chain dehydrogenase/reductase (SDR) within a genomic island from a clinical strain of Acinetobacter baumannii

    International Nuclear Information System (INIS)

    Shah, Bhumika S.; Tetu, Sasha G.; Harrop, Stephen J.; Paulsen, Ian T.; Mabbutt, Bridget C.

    2014-01-01

    The structure of a short-chain dehydrogenase encoded within genomic islands of A. baumannii strains has been solved to 2.4 Å resolution. This classical SDR incorporates a flexible helical subdomain. The NADP-binding site and catalytic side chains are identified. Over 15% of the genome of an Australian clinical isolate of Acinetobacter baumannii occurs within genomic islands. An uncharacterized protein encoded within one island feature common to this and other International Clone II strains has been studied by X-ray crystallography. The 2.4 Å resolution structure of SDR-WM99c reveals it to be a new member of the classical short-chain dehydrogenase/reductase (SDR) superfamily. The enzyme contains a nucleotide-binding domain and, like many other SDRs, is tetrameric in form. The active site contains a catalytic tetrad (Asn117, Ser146, Tyr159 and Lys163) and water molecules occupying the presumed NADP cofactor-binding pocket. An adjacent cleft is capped by a relatively mobile helical subdomain, which is well positioned to control substrate access

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

    Science.gov (United States)

    Singkham-In, Uthaibhorn; Chatsuwan, Tanittha

    2018-01-31

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

  18. Control of multidrug-resistant planktonic Acinetobacter baumannii: biocidal efficacy study by atmospheric-pressure air plasma

    Science.gov (United States)

    Zhe, RUAN; Yajun, GUO; Jing, GAO; Chunjun, YANG; Yan, LAN; Jie, SHEN; Zimu, XU; Cheng, CHENG; Xinghao, LIU; Shumei, ZHANG; Wenhui, DU; Paul, K. CHU

    2018-04-01

    In this research, an atmospheric-pressure air plasma is used to inactivate the multidrug-resistant Acinetobacter baumannii in liquid. The efficacy of the air plasma on bacterial deactivation and the cytobiological variations after the plasma treatment are investigated. According to colony forming units, nearly all the bacteria (6-log) are inactivated after 10 min of air plasma treatment. However, 7% of the bacteria enter a viable but non-culturable state detected by the resazurin based assay during the same period of plasma exposure. Meanwhile, 86% of the bacteria lose their membrane integrity in the light of SYTO 9/PI staining assay. The morphological changes in the cells are examined by scanning electron microscopy and bacteria with morphological changes are rare after plasma exposure in the liquid. The concentrations of the long-living RS, such as H2O2, {{{{NO}}}3}-, and O3, in liquid induced by plasma treatment are measured, and they increase with plasma treatment time. The changes of the intracellular ROS may be related to cell death, which may be attributed to oxidative stress and other damage effects induced by RS plasma generated in liquid. The rapid and effective bacteria inactivation may stem from the RS in the liquid generated by plasma and air plasmas may become a valuable therapy in the treatment of infected wounds.

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

    Science.gov (United States)

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

    2017-03-07

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

  20. Emergence of Oxacillinases in Environmental Carbapenem-Resistant Acinetobacter baumannii Associated with Clinical Isolates.

    Science.gov (United States)

    Goic-Barisic, Ivana; Hrenovic, Jasna; Kovacic, Ana; Musić, Martina Šeruga

    2016-10-01

    Six carbapenem-resistant isolates of Acinetobacter baumannii were recovered from untreated and treated municipal wastewater of the capital city of Zagreb, Croatia. Molecular identification of environmental isolates of A. baumannii was performed by amplification, sequencing, and phylogenetic analyses of rpoB gene. The presence of bla OXA genes encoding OXA-type carbapenemases (OXA-51-like, OXA-23, and OXA-40-like) was confirmed by multiplex PCR and sequencing. Phylogenetic analyses corroborated the affiliation of detected bla OXA genes to three different clusters and showed association of environmental OXAs with those described from clinical isolates. This result suggests that isolates recovered from municipal wastewater are most probably of clinical origin. Furthermore, the presence of OXA-40-like (OXA-72) in an environmental A. baumannii isolate is reported for the first time. Persistence of A. baumannii harboring the clinically important OXAs in the wastewater treatment process poses a potentially significant source for horizontal gene transfer and implications for wider spread of antibiotic resistance genes.

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

    Directory of Open Access Journals (Sweden)

    Dinesh M Fernando

    2016-11-01

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

  2. Differential Role of the T6SS in Acinetobacter baumannii Virulence

    Science.gov (United States)

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

    2015-01-01

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

  3. Differential Role of the T6SS in Acinetobacter baumannii Virulence.

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    Guillermo D Repizo

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

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

    Science.gov (United States)

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

    2016-10-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  6. Screening and Evaluation of the Bioremediation Potential of Cu/Zn-Resistant, Autochthonous Acinetobacter sp. FQ-44 from Sonchus oleraceus L.

    Science.gov (United States)

    Fang, Qing; Fan, Zhengqiu; Xie, Yujing; Wang, Xiangrong; Li, Kun; Liu, Yafeng

    2016-01-01

    The quest for new, promising and indigenous plant growth-promoting rhizobacteria and a deeper understanding of their relationship with plants are important considerations in the improvement of phytoremediation. This study focuses on the screening of plant beneficial Cu/Zn-resistant strains and assessment of their bioremediation potential (metal solubilization/tolerance/biosorption and effects on growth of Brassica napus seedlings) to identify suitable rhizobacteria and examine their roles in microbes-assisted phytoremediation. Sixty Cu/Zn-resistant rhizobacteria were initially isolated from Sonchus oleraceus grown at a multi-metal-polluted site in Shanghai, China. From these strains, 19 isolates that were all resistant to 300 mg⋅L -1 Cu as well as 300 mg⋅L -1 Zn, and could simultaneously grow on Dworkin-Foster salt minimal medium containing 1-aminocyclopropane-1-carboxylic acid were preliminarily selected. Of those 19 isolates, 10 isolates with superior plant growth-promoting properties (indole-3-acetic acid production, siderophore production, and insoluble phosphate solubilization) were secondly chosen and further evaluated to identify those with the highest bioremediation potential and capacity for bioaugmentation. Strain S44, identified as Acinetobacter sp. FQ-44 based on 16S rDNA sequencing, was specifically chosen as the most favorable strain owing to its strong capabilities to (1) promote the growth of rape seedlings (significantly increased root length, shoot length, and fresh weight by 92.60%, 31.00%, and 41.96%, respectively) under gnotobiotic conditions; (2) tolerate up to 1000 mg⋅L -1 Cu and 800 mg⋅L -1 Zn; (3) mobilize the highest concentrations of water-soluble Cu, Zn, Pb, and Fe (16.99, 0.98, 0.08, and 3.03 mg⋅L -1 , respectively); and (4) adsorb the greatest quantities of Cu and Zn (7.53 and 6.61 mg⋅g -1 dry cell, respectively). Our findings suggest that Acinetobacter sp. FQ-44 could be exploited for bacteria-assisted phytoextraction

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

    Science.gov (United States)

    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. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  8. Analysis of Acinetobacter baumannii resistance patterns in patients with chronic obstructive pulmonary disease (COPD in terms of choice of effective empiric antibiotic therapy

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    Aneta Grochowalska

    2017-06-01

    In the performed study, the infections caused by multi-resistant Acinetobacter baumannii, were observed in COPD, which should be taken into consideration in choosing empirical antibiotic therapy. Simultaneously, the local resistance patterns of multi-drug-resistant (MDR Gram-negative strains co-infecting COPD should be considered in empirical treatment. Moreover, both additional clinical complication and co-infections contribute to a more severe course of diseases. In this study, the mortality percent exceeded 29%.

  9. Trend of extensively drug-resistant Acinetobacter baumannii and the remaining therapeutic options: a multicenter study in Tehran, Iran over a 3-year period.

    Science.gov (United States)

    Jasemi, S; Douraghi, M; Adibhesami, H; Zeraati, H; Rahbar, M; Boroumand, M A; Aliramezani, A; Ghourchian, S; Mohammadzadeh, M

    2016-12-01

    Comprehensive data on drug-resistant patterns of Acinetobacter baumannii isolates in developing countries is limited. We conducted a multihospital study to assess the rate and trend of drug-resistant phenotypes in Ac. baumannii using standardized definitions and to determine the remaining therapeutic options against resistant phenotypes. The 401 nonduplicate isolates were collected from six hospitals which are geographically distributed across Tehran, Iran over a 3-year period. Following PCR of bla OXA -51-like gene, susceptibility testing was performed against nine antimicrobial agent categories. Three hundred and ninety (97%) isolates were resistant to least two carbapenems; carbapenem-resistant Ac. baumannii. The majority of isolates (366, 91·3%) were extensively drug resistant (XDR) and the rest of the isolates were classified as multidrug resistant (26, 6·8%) and susceptible (9, 2·2%). The rate of XDR-AB slightly decreased from 93·8% in 2011 to 89·8% in 2013. A considerable decrease in resistance to doxycycline, minocycline and tigecycline was demonstrated. The XDR-AB isolates showed susceptibility to gentamicin (10·4%), tobramycin (23%), ampicilin-sulbactam (30·1%), minocycline (32·8%), tigecycline (10·7%), doxycycline (21·6%), colistin (100%) and polymixin B (100%). We demonstrated the rising trend of resistance to all antibiotic categories except tetracyclines and folate pathway inhibitors. We found that the treatment options against XDR-AB are extremely limited and each treatment alternative including even old, but safe, antibiotics might be considered. The high frequency of drug-resistant phenotypes including carbapenem-resistant Acinetobacter baumannii, multidrug-resistant, and extensively resistant has been demonstrated in Ac. baumannii isolates tested here. As the antibiotic resistance pattern of isolates varies in different geographical regions, this study can provide comprehensive information about the antibiotic resistance profile of Ac

  10. Current Trends of Drug Resistance Patterns of Acinetobacter baumannii Infection in Blood Transfusion-dependent Thalassemia Patients.

    Science.gov (United States)

    Almani, Suhail Ahmed; Naseer, Ali; Maheshwari, Sanjay Kumar; Maroof, Pir; Naseer, Raza; Khoharo, Haji Khan

    2017-01-01

    The present study aimed to evaluate the current trends of drug resistance patterns of Acinetobacter baumannii infection in blood transfusion-dependent thalassemia patients. This study was a cross sectional study, conducted at the Liaquat University of Medical and Health Sciences, Jamshoro/Hyderabad, Sindh, Pakistan from October 2014 to January 2016. Of 921 blood samples, A. baumannii strains were isolated from 100 blood samples. Blood samples were processed for the isolation, identification, and drugs sensitivity as per the Clinical and Laboratory Standards Institute. A. baumannii strains were identified by microbiological methods and Gram's staining. API 20 E kit (Biomeriuex, USA) was also used for identification. Data were analyzed on Statisti × 8.1 (USA). Mean ± standard deviation age was 11.5 ± 2.8 years. Nearly 70% were male and 30% were female ( P = 0.0001). Of 921 blood transfusion-dependent thalassemia patients, 100 (10.8%) patients showed growth of A. baumannii . Drug resistance was observed against the ceftazidime, cefixime, cefepime, imipenem, meropenem, amikacin, minocycline, tigecycline, and tazocin except for the colistin. The present study reports drug-resistant A. baumannii in blood transfusion-dependent thalassemia patients. National multicenter studies are recommended to estimate the size of the problem.

  11. Características morfo-tintoriales en el ciclo celular de Acinetobacter baumannii por los métodos de Gram y 4’, 6-diamidino-2’-fenilindol, dihidrocloruro | Morphological and staining characteristics in cell cycle of Acinetobacter baumannii by the methods of Gram and 4´, 6-diamidino-2´-phenylindole, dihydrochloride

    Directory of Open Access Journals (Sweden)

    Evelin Flores Hernández

    2017-11-01

    Full Text Available Several studies have reported variations in bacterial staining by Gram, which are associated with the content of nucleic acids in the bacterial cell cycle. In order to give continuity to the microscopical studies pertaining to the bacterial cell cycle, the morphological and staining characteristics were evaluated by Gram and 4', 6-diamidino-2'-phenylindole, dihydrochloride (DAPI in the cell cycle of Acinetobacter baumannii. From the synchronic cultures of 4 strains of A. baumannii, the cell cycle was studied incubating them in aerobiosis at 30ºC, taking aliquots every 5 min for 2 h. In turn, the respective extensions were made and stained with Gram and DAPI for their posterior microscopical study. In the statistical analysis Fischer's test was used to associate morphological and the staining characteristics by Gram and DAPI. In 74% of cycle times, the cocoid form predominated and 67% in the negative Gram staining. When determining the mean and standard deviation of bacterial morphological values, it was observed that between 15 and 55 min the bacterium initiates a new cell cycle, decreasing its diameter and length. There was a statistically significant association (p < 0.05 between the lax and compact appearance of the material with the light and intense fluorescent, respectively; likewise, between the strong Gram positive character and the intense fluorescence. It is concluded that in the Gram positive reaction, the DNA is possibly involved and that the purple material of compact and lax aspect observed by Gram staining in the bacterial cytoplasm correspond to the nucleoid and the morphological changes obey to the cellular growth process. These findings contribute to explain the mechanism of Gram staining, as well as its variability and the pleomorphism observed in this bacterial genus.

  12. Comparative Genomic Analysis of Rapid Evolution of an Extreme-Drug-Resistant Acinetobacter baumannii Clone

    DEFF Research Database (Denmark)

    Tan, Sean Yang-Yi; Chua, Song Lin; Liu, Yang

    2013-01-01

    , comparative genomics has been employed to analyze the rapid evolution of an EDR Acinetobacter baumannii clone from the intensive care unit (ICU) of Rigshospitalet at Copenhagen. Two resistant A. baumannii strains, 48055 and 53264, were sequentially isolated from two individuals who had been admitted to ICU...... within a 1-month interval. Multilocus sequence typing indicates that these two isolates belonged to ST208. The A. baumannii 53264 strain gained colistin resistance compared with the 48055 strain and became an EDR strain. Genome sequencing indicates that A. baumannii 53264 and 48055 have almost identical...... genomes—61 single-nucleotide polymorphisms (SNPs) were found between them. The A. baumannii 53264 strain was assembled into 130 contigs, with a total length of 3,976,592 bp with 38.93% GC content. The A. baumannii 48055 strain was assembled into 135 contigs, with a total length of 4,049,562 bp with 39...

  13. Biological effects of carvacrol and cinnamaldehyde on Acinetobacter baumannii

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    Angélique Montagu

    2016-07-01

    Full Text Available 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 (ROS in response to environmental stress conditions, such as carvacrol.

  14. Global regulator SoxR is a negative regulator of efflux pump gene expression and affects antibiotic resistance and fitness in Acinetobacter baumannii.

    Science.gov (United States)

    Li, Henan; Wang, Qi; Wang, Ruobing; Zhang, Yawei; Wang, Xiaojuan; Wang, Hui

    2017-06-01

    SoxR is a global regulator contributing to multidrug resistance in Enterobacteriaceae. However, the contribution of SoxR to antibiotic resistance and fitness in Acinetobacter baumannii has not yet been studied. Comparisons of molecular characteristics were performed between 32 multidrug-resistant A. baumannii isolates and 11 susceptible isolates. A soxR overexpression mutant was constructed, and its resistance phenotype was analyzed. The impact of SoxR on efflux pump gene expression was measured at the transcription level. The effect of SoxR on the growth and fitness of A. baumannii was analyzed using a growth rate assay and an in vitro competition assay. The frequency of the Gly39Ser mutation in soxR was higher in multidrug-resistant A. baumannii, whereas the soxS gene was absent in all strains analyzed. SoxR overexpression led to increased susceptibility to chloramphenicol (4-fold), tetracycline (2-fold), tigecycline (2-fold), ciprofloxacin (2-fold), amikacin (2-fold), and trimethoprim (2-fold), but it did not influence imipenem susceptibility. Decreased expression of abeS (3.8-fold), abeM (1.3-fold), adeJ (2.4-fold), and adeG (2.5-fold) were correlated with soxR overexpression (P baumannii.

  15. Molecular mechanisms associated with nosocomial carbapenem-resistant Acinetobacter baumannii in Mexico.

    Science.gov (United States)

    Alcántar-Curiel, María Dolores; García-Torres, Luis Francisco; González-Chávez, María Inés; Morfín-Otero, Rayo; Gayosso-Vázquez, Catalina; Jarillo-Quijada, Ma Dolores; Fernández-Vázquez, José Luis; Giono-Cerezo, Silvia; Rodríguez-Noriega, Eduardo; Santos-Preciado, José Ignacio

    2014-10-01

    Acinetobacter baumannii is an emerging pathogen worldwide that is most commonly associated with nosocomial infections and multi-drug resistance. In the present study we determined the mechanisms of carbapenem resistance and clonal diversity of A. baumannii nosocomial isolates in Hospital Civil de Guadalajara, Mexico. A total of 303 clinical isolates of A. baumannii identified during a period expanding from 2004-2011 were analyzed for carbapenem resistance using several microbiological and molecular methods. Clonal relatedness of these isolates was determined using pulsed-field gel electrophoresis. Of the 303 isolates, 84% were resistant to meropenem, 71.3% to imipenem and 78.3% the resistant isolates were positive for metallo-β-lactamases as determined by the phenotypic assay. In addition, 49.6% of carbapenem-intermediate or -resistant isolates carried the blaOXA-72 gene and 1.2% carried the blaVIM-1 gene. Efflux pump phenotype was responsible for reduced susceptibility to meropenem in 14.5% and to imipenem in 31.6% of the resistant isolates, respectively in the presence of the efflux pump inhibitor, carbonyl cyanide 3-chlorophenylhydrazone. Strains representing different carbapenem-resistant patterns exhibited reduced expression of 22, 29, 33, and 43 kDa OMPs. Among the bacterial collection studied, 48 different clones were identified, two of which were predominant and persistently transmitted. Carbapenemase production in combination with efflux pump expression, reduction in OMPs expression and the cross-transmission of clones appear to be major contributors to the high frequency of carbapenem-resistance observed in A. baumannii. To our knowledge, this is the first study to define the molecular mechanisms associated with carbapenem-resistance in A. baumannii in Mexico. Copyright © 2014 IMSS. Published by Elsevier Inc. All rights reserved.

  16. A new trilocus sequence-based multiplex-PCR to detect major Acinetobacter baumannii clones.

    Science.gov (United States)

    Martins, Natacha; Picão, Renata Cristina; Cerqueira-Alves, Morgana; Uehara, Aline; Barbosa, Lívia Carvalho; Riley, Lee W; Moreira, Beatriz Meurer

    2016-08-01

    A collection of 163 Acinetobacter baumannii isolates detected in a large Brazilian hospital, was potentially related with the dissemination of four clonal complexes (CC): 113/79, 103/15, 109/1 and 110/25, defined by University of Oxford/Institut Pasteur multilocus sequence typing (MLST) schemes. The urge of a simple multiplex-PCR scheme to specify these clones has motivated the present study. The established trilocus sequence-based typing (3LST, for ompA, csuE and blaOXA-51-like genes) multiplex-PCR rapidly identifies international clones I (CC109/1), II (CC118/2) and III (CC187/3). Thus, the system detects only one (CC109/1) out of four main CC in Brazil. We aimed to develop an alternative multiplex-PCR scheme to detect these clones, known to be present additionally in Africa, Asia, Europe, USA and South America. MLST, performed in the present study to complement typing our whole collection of isolates, confirmed that all isolates belonged to the same four CC detected previously. When typed by 3LST-based multiplex-PCR, only 12% of the 163 isolates were classified into groups. By comparative sequence analysis of ompA, csuE and blaOXA-51-like genes, a set of eight primers was designed for an alternative multiplex-PCR to distinguish the five CC 113/79, 103/15, 109/1, 110/25 and 118/2. Study isolates and one CC118/2 isolate were blind-tested with the new alternative PCR scheme; all were correctly clustered in groups of the corresponding CC. The new multiplex-PCR, with the advantage of fitting in a single reaction, detects five leading A. baumannii clones and could help preventing the spread in healthcare settings. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Characterization of phenols biodegradation by compound specific stable isotope analysis

    Science.gov (United States)

    Wei, Xi; Gilevska, Tetyana; Wenzig, Felix; Hans, Richnow; Vogt, Carsten

    2015-04-01

    Biodegradation of phenol and alkylphenols has been described under both oxic and anoxic conditions. In the absence of molecular oxygen, the degradation of phenolic compounds is initiated by microorganisms through carboxylation, fumarate addition to the methyl moiety or anoxic hydroxylation of the methyl moiety. Comparatively, under aerobic condition, the initiation mechanisms are revealed to be monoxygenation or dihydroxylation for phenol and ring hydroxylation or methyl group oxidation for cresols. While several studies biochemically characterized the enzymes and reaction mechanisms in the relevant degradation pathways, isotope fractionation patterns were rarely reported possibly due to constraints in current analytical methods. In this study, the carbon isotope fractionation patterns upon the degradation of phenol and cresols by several strains were analyzed by using isotope ratio mass spectrometry connected with liquid chromatography (LC-IRMS). The corresponding enrichment factors for carbon (ƐC) have been obtained. Cresols degradation by various strains showed generally moderate carbon isotope fractionation patterns with notable differences. For p-cresol degradation, five strains were examined. The aerobic strain Acinetobacter calcoaceticus NCIMB8250 exploits ring hydroxylation by molecular oxygen as initial reaction, and a ƐC value of -1.4±0.2‰ was obtained. Pseudomonas pseudoalcaligenes NCIMB 9867, an aerobic strain initiating cresols degradation via oxygen-dependent side chain hydroxylation, yielded a ƐC value of -2.3±0.2‰. Under nitrate-reducing conditions, Geobacter metallireducens DSM 7210 and Azoarcus buckelii DSM 14744 attacks p-cresol at the side chain by monohydroxylation using water as oxygen source; the two strains produced ƐC values of -3.6±0.4‰ and -2±0.1‰, accordingly. The sulfate-reducing Desulfosarcina cetonica DSM 7267 activating cresols by fumarate addition to the methyl moiety yielded ƐC values of -1.9±0.2‰ for p

  18. Isolation and characterization of ZZ1, a novel lytic phage that infects Acinetobacter baumannii clinical isolates

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    Jin Jing

    2012-07-01

    Full Text Available Abstract Background Acinetobacter baumannii, a significant nosocomial pathogen, has evolved resistance to almost all conventional antimicrobial drugs. Bacteriophage therapy is a potential alternative treatment for multidrug-resistant bacterial infections. In this study, one lytic bacteriophage, ZZ1, which infects A. baumannii and has a broad host range, was selected for characterization. Results Phage ZZ1 and 3 of its natural hosts, A. baumanni clinical isolates AB09V, AB0902, and AB0901, are described in this study. The 3 strains have different sensitivities to ZZ1, but they have the same sensitivity to antibiotics. They are resistant to almost all of the antibiotics tested, except for polymyxin. Several aspects of the life cycle of ZZ1 were investigated using the sensitive strain AB09V under optimal growth conditions. ZZ1 is highly infectious with a short latent period (9 min and a large burst size (200 PFU/cell. It exhibited the most powerful antibacterial activity at temperatures ranging from 35°C to 39°C. Moreover, when ZZ1 alone was incubated at different pHs and different temperatures, the phage was stable over a wide pH range (4 to 9 and at extreme temperatures (between 50°C and 60°C. ZZ1 possesses a 100-nm icosahedral head containing double-stranded DNA with a total length of 166,682 bp and a 120-nm long contractile tail. Morphologically, it could be classified as a member of the Myoviridae family and the Caudovirales order. Bioinformatic analysis of the phage whole genome sequence further suggested that ZZ1 was more likely to be a new member of the Myoviridae phages. Most of the predicted ORFs of the phage were similar to the predicted ORFs from other Acinetobacter phages. Conclusion The phage ZZ1 has a relatively broad lytic spectrum, high pH stability, strong heat resistance, and efficient antibacterial potential at body temperature. These characteristics greatly increase the utility of this phage as an antibacterial agent

  19. Isolation and characterization of ZZ1, a novel lytic phage that infects Acinetobacter baumannii clinical isolates.

    Science.gov (United States)

    Jin, Jing; Li, Zhen-Jiang; Wang, Shu-Wei; Wang, Shan-Mei; Huang, De-Hai; Li, Ya-Hui; Ma, Yun-Yun; Wang, Jin; Liu, Fang; Chen, Xiang-Dong; Li, Guang-Xing; Wang, Xiao-Ting; Wang, Zhong-Quan; Zhao, Guo-Qiang

    2012-07-28

    Acinetobacter baumannii, a significant nosocomial pathogen, has evolved resistance to almost all conventional antimicrobial drugs. Bacteriophage therapy is a potential alternative treatment for multidrug-resistant bacterial infections. In this study, one lytic bacteriophage, ZZ1, which infects A. baumannii and has a broad host range, was selected for characterization. Phage ZZ1 and 3 of its natural hosts, A. baumanni clinical isolates AB09V, AB0902, and AB0901, are described in this study. The 3 strains have different sensitivities to ZZ1, but they have the same sensitivity to antibiotics. They are resistant to almost all of the antibiotics tested, except for polymyxin. Several aspects of the life cycle of ZZ1 were investigated using the sensitive strain AB09V under optimal growth conditions. ZZ1 is highly infectious with a short latent period (9 min) and a large burst size (200 PFU/cell). It exhibited the most powerful antibacterial activity at temperatures ranging from 35°C to 39°C. Moreover, when ZZ1 alone was incubated at different pHs and different temperatures, the phage was stable over a wide pH range (4 to 9) and at extreme temperatures (between 50°C and 60°C). ZZ1 possesses a 100-nm icosahedral head containing double-stranded DNA with a total length of 166,682 bp and a 120-nm long contractile tail. Morphologically, it could be classified as a member of the Myoviridae family and the Caudovirales order. Bioinformatic analysis of the phage whole genome sequence further suggested that ZZ1 was more likely to be a new member of the Myoviridae phages. Most of the predicted ORFs of the phage were similar to the predicted ORFs from other Acinetobacter phages. The phage ZZ1 has a relatively broad lytic spectrum, high pH stability, strong heat resistance, and efficient antibacterial potential at body temperature. These characteristics greatly increase the utility of this phage as an antibacterial agent; thus, it should be further investigated.

  20. Polyaspartamide-Based Nanoparticles Loaded with Fluticasone Propionate and the In Vitro Evaluation towards Cigarette Smoke Effects

    Directory of Open Access Journals (Sweden)

    Emanuela Fabiola Craparo

    2017-08-01

    Full Text Available This paper describes the evaluation of polymeric nanoparticles (NPs as a potential carrier for lung administration of fluticasone propionate (FP. The chosen polymeric material to produce NPs was a copolymer based on α,β-poly(N-2-hydroxyethyl-d,l-aspartamide (PHEA whose backbone was derivatised with different molecules, such as poly(lactic acid (PLA and polyethylenglycol (PEG. The chosen method to produce NPs from PHEA-PLA-PEG2000 was the method based on high-pressure homogenization and subsequent solvent evaporation by adding Pluronic F68 during the process and trehalose before lyophilisation. Obtained colloidal FP-loaded NPs showed a slightly negative surface charge and nanometric dimensions that are maintained after storage for one year at −20 °C and 5 °C. The FP loading was about 2.9 wt % and the drug was slowly released in simulated lung fluid. Moreover, the obtained NPs, containing the drug or not, were biocompatible and did not induce cell necrosis and cell apoptosis on bronchial epithelial cells (16-HBE. Further in vitro testing on cigarette smoke extract (CSE-stimulated 16-HBE revealed that FP-loaded NPs were able to reduce the survivin expression, while either free FP or empty NPs were not able to significantly reduce this effect.

  1. Outbreak of imipenem-resistant Acinetobacter baumannii in different wards at a regional hospital related to untrained bedside caregivers.

    Science.gov (United States)

    Wang, Ching-Hsun; Li, Jin-Feng; Huang, Li-Yueh; Lin, Fu-Mei; Yang, Ya-Sung; Siu, L Kristopher; Chang, Feng-Yee; Lin, Jung-Chung

    2017-10-01

    This study describes an outbreak caused by imipenem-resistant Acinetobacter baumannii (IRAB) involving 2 general wards at the Penghu branch of Tri-Service General Hospital. Clinical data obtained from the patients with IRAB during an outbreak from May 2014-October 2014 were reviewed. Microbiologic sampling from the environment and the hands of health care workers (HCWs) was performed. Clinical isolates from case patients were genotyped using pulsed-field gel electrophoresis (PFGE). During the outbreak period, 12 patients were colonized or infected with IRAB. The hospital room environments of the case patients were contaminated with IRAB. Hands of nurses and physicians were not colonized with IRAB, but the hands of 2 bedside caregivers of case patients were colonized with IRAB. The PFGE analysis revealed that at least 2 major genetically distinct strains disseminated between 2 different wards. After implementation of infection control measures with a cohort of nursing patients, hand hygiene education for caregivers who had not received instructions before the outbreak, and a critical value alert system to notify case patients, the outbreak was controlled successfully. This outbreak study highlights the importance of adherence to hand hygiene by all HCWs to prevent the dissemination of multidrug-resistant organisms. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  2. K19 capsular polysaccharide of Acinetobacter baumannii is produced via a Wzy polymerase encoded in a small genomic island rather than the KL19 capsule gene cluster.

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    Kenyon, Johanna J; Shneider, Mikhail M; Senchenkova, Sofya N; Shashkov, Alexander S; Siniagina, Maria N; Malanin, Sergey Y; Popova, Anastasiya V; Miroshnikov, Konstantin A; Hall, Ruth M; Knirel, Yuriy A

    2016-08-01

    Polymerization of the oligosaccharides (K units) of complex capsular polysaccharides (CPSs) requires a Wzy polymerase, which is usually encoded in the gene cluster that directs K unit synthesis. Here, a gene cluster at the Acinetobacter K locus (KL) that lacks a wzy gene, KL19, was found in Acinetobacter baumannii ST111 isolates 28 and RBH2 recovered from hospitals in the Russian Federation and Australia, respectively. However, these isolates produced long-chain capsule, and a wzy gene was found in a 6.1 kb genomic island (GI) located adjacent to the cpn60 gene. The GI also includes an acetyltransferase gene, atr25, which is interrupted by an insertion sequence (IS) in RBH2. The capsule structure from both strains was →3)-α-d-GalpNAc-(1→4)-α-d-GalpNAcA-(1→3)-β-d-QuipNAc4NAc-(1→, determined using NMR spectroscopy. Biosynthesis of the K unit was inferred to be initiated with QuiNAc4NAc, and hence the Wzy forms the β-(1→3) linkage between QuipNAc4NAc and GalpNAc. The GalpNAc residue is 6-O-acetylated in isolate 28 only, showing that atr25 is responsible for this acetylation. The same GI with or without an IS in atr25 was found in draft genomes of other KL19 isolates, as well as ones carrying a closely related CPS gene cluster, KL39, which differs from KL19 only in a gene for an acyltransferase in the QuiNAc4NR synthesis pathway. Isolates carrying a KL1 variant with the wzy and atr genes each interrupted by an ISAba125 also have this GI. To our knowledge, this study is the first report of genes involved in capsule biosynthesis normally found at the KL located elsewhere in A. baumannii genomes.

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

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

    2017-09-01

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

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

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

    2014-07-01

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

  5. Coexistence of blaOXA-23 with armA in quinolone-resistant Acinetobacter baumannii from a Chinese university hospital.

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    Shen, Min; Luan, Guangxin; Wang, Yanhong; Chang, Yaowen; Zhang, Chi; Yang, Jingni; Deng, Shanshan; Ling, Baodong; Jia, Xu

    2016-03-01

    A total of 101 Acinetobacter baumannii isolates were collected to determine the mechanisms of quinolone resistance and investigate the occurrence of carbapenem and high-level aminoglycoside resistance genes among quinolone-resistant strains. Among 77 quinolone-resistant A. baumannii harbored mutations of gyrA and parC, 41 isolates, which belonged to European clone II, had resistance to aminoglycosides and carbapenems due to the expression of armA and acquisition of blaOXA-23. Most of sequence type belonged to clonal complex 92. These results suggested hospital dissemination of multidrug-resistant A. baumannii carrying blaOXA-23, armA, and mutations of quinolone resistance-determining regions in western China. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. The Immune Response against Acinetobacter baumannii, an Emerging Pathogen in Nosocomial Infections

    Science.gov (United States)

    García-Patiño, María Guadalupe; García-Contreras, Rodolfo; Licona-Limón, Paula

    2017-01-01

    Acinetobacter baumannii is the etiologic agent of a wide range of nosocomial infections, including pneumonia, bacteremia, and skin infections. Over the last 45 years, an alarming increase in the antibiotic resistance of this opportunistic microorganism has been reported, a situation that hinders effective treatments. In order to develop effective therapies against A. baumannii it is crucial to understand the basis of host–bacterium interactions, especially those concerning the immune response of the host. Different innate immune cells such as monocytes, macrophages, dendritic cells, and natural killer cells have been identified as important effectors in the defense against A. baumannii; among them, neutrophils represent a key immune cell indispensable for the control of the infection. Several immune strategies to combat A. baumannii have been identified such as recognition of the bacteria by immune cells through pattern recognition receptors, specifically toll-like receptors, which trigger bactericidal mechanisms including oxidative burst and cytokine and chemokine production to amplify the immune response against the pathogen. However, a complete picture of the protective immune strategies activated by this bacteria and its potential therapeutic use remains to be determined and explored. PMID:28446911

  7. Characterization of Acinetobacter baumannii biofilm associated components

    Science.gov (United States)

    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

  8. Carbapenem-resistant Acinetobacter baumannii from Serbia: revision of CarO classification.

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    Katarina Novovic

    Full Text Available Carbapenem-resistant A. baumannii present a significant therapeutic challenge for the treatment of nosocomial infections in many European countries. Although it is known that the gradient of A. baumannii prevalence increases from northern to southern Europe, this study provides the first data from Serbia. Twenty-eight carbapenem-resistant A. baumannii clinical isolates were collected at a Serbian pediatric hospital during a 2-year period. The majority of isolates (67.68% belonged to the sequence type Group 1, European clonal complex II. All isolates harbored intrinsic OXA-51 and AmpC cephalosporinase. OXA-23 was detected in 16 isolates (57.14%, OXA-24 in 23 isolates (82.14% and OXA-58 in 11 isolates (39.29%. Six of the isolates (21.43% harbored all of the analyzed oxacillinases, except OXA-143 and OXA-235 that were not detected in this study. Production of oxacillinases was detected in different pulsotypes indicating the presence of horizontal gene transfer. NDM-1, VIM and IMP were not detected in analyzed clinical A. baumannii isolates. ISAba1 insertion sequence was present upstream of OXA-51 in one isolate, upstream of AmpC in 13 isolates and upstream of OXA-23 in 10 isolates. In silico analysis of carO sequences from analyzed A. baumannii isolates revealed the existence of two out of six highly polymorphic CarO variants. The phylogenetic analysis of CarO protein among Acinetobacter species revised the previous classification CarO variants into three groups based on strong bootstraps scores in the tree analysis. Group I comprises four variants (I-IV while Groups II and III contain only one variant each. One half of the Serbian clinical isolates belong to Group I variant I, while the other half belongs to Group I variant III.

  9. Synthesis, characterization and antibacterial activity of a new calcium complex using sodium 2-mercaptobenzothiazole and 1, 10-phenanthroline as ligands

    Science.gov (United States)

    Gulab, Hussain; Shah, Zarbad; Mahmood, Mazhar; Shah, Syed Raza; Ali, Sajid; Iqbal, Muhammad; Khan, Muhammad Naeem; Flörke, Ulrich; Khan, Shahid Ali

    2018-02-01

    A new Ca-complex (Ca (H2 O)4 (C12 H8 N2)2)(C7 H4 N S2)2 has been synthesized by the reaction of calcium chloride, sodium 2-mercaptobenzothiazole and 1,10-phenanthroline. The complex was characterized by using X-ray crystallography and FT-IR spectroscopy. The complex was tested against different bacterial strains i.e. Staphylococcus aureus, Escherichia coli, Acinetobacter baumanni, Providencia stuartii and Pseudomonas aeruginosa. The complex was found to exhibit remarkable anti-bacterial activity against Pseudomonas aeruginosa with an inhibition zone of 25 mm and good anti-bacterial activity against Acinetobacter baumanni with a zone of inhibition of 16 mm comparable to the Levofloxacin standard (zone of inhibition of 25 mm).

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

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    Steven E Fiester

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

  11. Acquisition and clearance of multidrug resistant Acinetobacter baumannii on healthy young adults concurrently burned in a dust explosion in Taiwan: the implication for antimicrobial stewardship.

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    Huang, Po-Yen; Shie, Shian-Sen; Ye, Jung-Jr; Lin, Shih-Pin; Liu, Tsui-Ping; Wu, Ting-Shu; Wu, Tsu-Lan; Chuang, Shiow-Shuh; Cheng, Ming-Huei; Hsieh, Yu-Chia; Huang, Ching-Tai

    2017-08-30

    Information is limited about the effect of restricted carbapenem use on clearance of multi-drug resistant Acinetobacter baumannii (MDRAB). We sought to determine the time effect of antibiotic exposure on multi-drug resistant Acinetobacter baumannii (MDRAB) acquisition and clearance. We conducted a retrospective observational study at the intensive care units of a tertiary medical center. Forty-two of a cohort of previously healthy young adults who were concurrently burned by a dust explosion was included. Cases consisted of those from whom MDRAB was isolated during hospitalization. Controls consisted of patients from whom MDRAB was not isolated in the same period. Use of antimicrobial agents was compared based on days of therapy per 1,000 patient-days (DOT/1,000PD). A 2-state Markov multi-state model was used to estimate the risk of acquisition and clearance of MDRAB. MDRAB was discovered in 9/42 (21.4%) individuals. The cases had significantly higher use of carbapenem (652 DOT/1,000PD vs. 385 DOT/1,000PD, P < 0.001) before MDRAB isolation. For the cases, clearance of MDRAB was associated with lower use of carbapenem (469 DOT/1,000PD vs. 708 DOT/1,000PD, P = 0.003) and higher use of non-carbapenem beta-lactam (612 DOT/1,000PD vs. 246 DOT/1,000PD, P <0.001). In multi-state model, each additional DOT of carbapenem increased the hazard of acquiring MDRAB (hazard ratio (HR), 1.08; 95% confidence interval (CI) 1.01-1.16) and each additional DOT of non-carbapenem beta-lactam increased the protection of clearing MDRAB (HR, 1.25; 95% CI 1.07-1.46). Both acquisition and clearance of MDRAB were related to antibiotic exposure in a homogeneous population. Our findings suggest that early discontinuation of carbapenem could be an effective measure in antibiotic stewardship for the control of MDRAB spreading.

  12. Outbreak of resistant Acinetobacter baumannii- measures and proposal for prevention and control.

    Science.gov (United States)

    Romanelli, Roberta Maia de Castro; Jesus, Lenize Adriana de; Clemente, Wanessa Trindade; Lima, Stella Sala Soares; Rezende, Edna Maria; Coutinho, Rosane Luiza; Moreira, Ricardo Luiz Fontes; Neves, Francelli Aparecida Cordeiro; Brás, Nelma de Jesus

    2009-10-01

    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.

  13. Outbreak of resistant Acinetobacter baumannii: measures and proposal for prevention and control

    Directory of Open Access Journals (Sweden)

    Roberta Maia de Castro Romanelli

    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.

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

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    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.

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

    Science.gov (United States)

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

    2018-03-20

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

  16. Screening and Evaluation of the Bioremediation Potential of Cu/Zn-resistant, Autochthonous Acinetobacter sp. FQ-44 from Sonchus oleraceus L.

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    Qing Fang

    2016-09-01

    Full Text Available The quest for new, promising and indigenous plant growth-promoting rhizobacteria and a deeper understanding of their relationship with plants are important considerations in the improvement of phytoremediation. This study focuses on the screening of plant beneficial Cu/Zn-resistant strains and assessment of their bioremediation potential (metal solubilization/tolerance/biosorption and effects on growth of Brassica napus seedlings to identify suitable rhizobacteria and examine their roles in microbes-assisted phytoremediation. Sixty Cu/Zn-resistant rhizobacteria were initially isolated from Sonchus oleraceus grown at a multi-metal-polluted site in Shanghai, China. From these strains, 19 isolates that were all resistant to 300 mg·L-1 Cu as well as 300 mg·L-1 Zn, and could simultaneously grow on Dworkin-Foster salt minimal medium containing 1-aminocyclopropane-1-carboxylic acid were preliminarily selected. Of those 19 isolates, 10 isolates with superior plant growth-promoting properties (indole-3-acetic acid production, siderophore production and insoluble phosphate solubilization were secondly chosen and further evaluated to identify those with the highest bioremediation potential and capacity for bioaugmentation. Strain S44, identified as Acinetobacter sp. FQ-44 based on 16S rDNA sequencing, was specifically chosen as the most favorable strain owing to its strong capabilities to (1 promote the growth of rape seedlings (significantly increased root length, shoot length and fresh weight by 92.60%, 31.00% and 41.96%, respectively under gnotobiotic conditions; (2 tolerate up to 1000 mg·L-1 Cu and 800 mg·L-1 Zn; (3 mobilize the highest concentrations of water-soluble Cu, Zn, Pb and Fe (16.99, 0.98, 0.08 and 3.03 mg·L-1, respectively; and (4 adsorb the greatest quantities of Cu and Zn (7.53 and 6.61 mg·g-1 dry cell, respectively. Our findings suggest that Acinetobacter sp. FQ-44 could be exploited for bacteria-assisted phytoextraction. Moreover

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

    Science.gov (United States)

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

    2017-06-01

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

  18. PER-8, a Novel Extended-Spectrum β-Lactamase PER Variant, from an Acinetobacter baumannii Clinical Isolate in Nepal.

    Science.gov (United States)

    Tada, Tatsuya; Shrestha, Shovita; Shimada, Kayo; Ohara, Hiroshi; Sherchand, Jeevan B; Pokhrel, Bharat M; Kirikae, Teruo

    2017-03-01

    A novel PER-type extended-spectrum β-lactamase, PER-8, was identified in an Acinetobacter baumannii clinical isolate obtained in Nepal. The amino acid sequence of PER-8 has a substitution at position 39 (Gly to Glu) compared with that of PER-7. The k cat / K m ratio of PER-8 for aztreonam was lower than that of PER-7, while the k cat / K m ratio of PER-8 for imipenem was higher than that of PER-7. The genomic environment surrounding bla PER-8 was intI1 bla PSE-1 qacEDI sulI IS CR1-bla PER-8 gts sulI orfX on a 100-kb plasmid. Copyright © 2017 American Society for Microbiology.

  19. Antibacterial activity in spices and local medicinal plants against clinical isolates of Karachi, Pakistan.

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    Ali, Nafisa Hassan; Faizi, Shaheen; Kazmi, Shahana Urooj

    2011-08-01

    Development of resistance in human pathogens against conventional antibiotic necessitates searching indigenous medicinal plants having antibacterial property. Twenty-seven medicinal plants used actively in folklore, ayurvedic and traditional system of medicine were selected for the evaluation of their antimicrobial activity for this study. Eleven plants chosen from these 27 are used as spices in local cuisine. Evaluation of the effectiveness of some medicinal plant extracts against clinical isolates. Nonedible plant parts were extracted with methanol and evaporated in vacuo to obtain residue. Powdered edible parts were boiled three times and cooled in sterile distilled water for 2 min each and filtrate collected. The minimum inhibitory concentration (MIC) of plant extracts and filtrates/antibiotics was evaluated against clinical isolates by microbroth dilution method. Water extract of Syzygium aromaticum L. (Myrtaceae) buds, methanol extracts of Ficus carica L. (Moraceae) and Olea europaea L. (Oleaceae) leaves and Peganum harmala L. (Nitrariaceae) seeds had MIC ranges of 31.25-250 µg/ml. S. aromaticum inhibited growth of Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Salmonella enterica serovar Typhi and Pseudomonas aeruginosa. F. carica and O. europaea inhibited growth of S. aureus, S. epidermidis, and S. pyogenes whereas P. harmala was effective against S. aureus, Acinetobacter calcoaceticus and Candida albicans. Ampicillin, velosef, sulfamethoxazole, tetracycline and ceftazidime, cefotaxime, cefepime, which are used as control, had MIC ≥ 50 and 1.5 µg/ml, respectively, for organisms sensitive to extracts. Mono/multiextract from identified plants will provide an array of safe antimicrobial agents to control infections by drug-resistant bacteria.

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

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    Mirna Ćurković-Perica

    2015-07-01

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

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

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    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.

  2. Analysis of Acinetobacter baumannii resistance patterns in patients with chronic obstructive pulmonary disease (COPD) in terms of choice of effective empiric antibiotic therapy.

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    Grochowalska, Aneta; Kozioł-Montewka, Maria; Sobieszczańska, Anna

    2017-06-12

    Introduction. Multi-resistant Acinetobacter baumannii isolated from patients has become one of the most hazardous pathogens in health care settings. The aim of the study was to analyze pneumonia caused by Acinetobacter baumannii in patients hospitalized because of exacerbation of chronic obstructive pulmonary diseases (COPD), who were admitted to the Pulmonology Ward of the Masovian Specialistic Hospital in Radom (MSS). The incidence and drug sensitivity of these non-fermenting rods were evaluated, and compliance with antimicrobial procedure with the algorithm of the guidelines in applicable recommendations, was estimated. This should result in determining the local patterns of resistance and verifying therapeutic procedures in accordance with the assumptions of hospital antibiotic policy. In addition, the study examined the effectiveness of empiric and targeted therapy according to the clinical condition of the patient, and the eradication of A. baumannii, in comparison with the aggravating factors of the patient. Materials and Method. The retrospective study included 90 patients with exacerbation of COPD whose etiological factor of infection was A. baumannii, hospitalized in the Department of Pulmonology (MSS) in 2012-2016. Results. Studies were conducted on 90 patients with COPD exacerbation from which A. baumannii was isolated. Co-infections with other bacterial species among 41 patients were additionally noted. The majority of A. baumannii strains showed a high resistance (90%) to fluoroquinolones, ceftazidime, piperacillin/tazobactam. For strains causing a co-infection, drug resistance was successively 44-56%, 44%, 44%. All of patients received empirical therapy. The most commonly used drug was amoxicillin with a clavulanic acid, often combined with fluoroquinolone. This type of therapy was effective among 10% of patients. The mortality in this group was determined at 29%. Among 79% of patients with COPD, a targeted therapy was performed which proved to be

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

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    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%, PCandida spp. airway colonization (43%) and A. baumannii VAP (18%) were common in ICU patients who were on mechanical ventilation for at least 48 hours. Candida spp. airway colonization was an independent risk factor for subsequent A. baumannii VAP. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. In vitro characterization of multivalent adhesion molecule 7-based inhibition of multidrug-resistant bacteria isolated from wounded military personnel

    Science.gov (United States)

    Krachler, Anne Marie; Mende, Katrin; Murray, Clinton; Orth, Kim

    2012-01-01

    Treatment of wounded military personnel at military medical centers is often complicated by colonization and infection of wounds with pathogenic bacteria. These include nosocomially transmitted, often multidrug-resistant pathogens such as Acinetobacter baumannii-calcoaceticus complex, Pseudomonas aeruginosa and extended spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae. We analyzed the efficacy of multivalent adhesion molecule (MAM) 7-based anti-adhesion treatment of host cells against aforementioned pathogens in a tissue culture infection model. Herein, we observed that a correlation between two important hallmarks of virulence, attachment and cytotoxicity, could serve as a useful predictor for the success of MAM7-based inhibition against bacterial infections. Initially, we characterized 20 patient isolates (five from each pathogen mentioned above) in terms of genotypic diversity, antimicrobial susceptibility and important hallmarks of pathogenicity (biofilm formation, attachment to and cytotoxicity toward cultured host cells). All isolates displayed a high degree of genotypic diversity, which was also reflected by large strain-to-strain variability in terms of biofilm formation, attachment and cytotoxicity within each group of pathogen. Using non-pathogenic bacteria expressing MAM7 or latex beads coated with recombinant MAM7 for anti-adhesion treatment, we showed a decrease in cytotoxicity, indicating that MAM7 has potential as a prophylactic agent to attenuate infection by multidrug-resistant bacterial pathogens. PMID:22722243

  5. Bioemulsan Production by Iranian Oil Reservoirs Microorganisms

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    A Amiriyan, M Mazaheri Assadi, VA Saggadian, A Noohi

    2004-10-01

    Full Text Available The biosurfactants are believed to be surface active components that are shed into the surrounding medium during the growth of the microorganisms. The oil degrading microorganism Acinetobacter calcoaceticus RAG-1 produces a poly-anionic biosurfactant, hetero-polysaccharide bioemulsifier termed as emulsan which forms and stabilizes oil-water emulsions with a variety of hydrophobic substrates. In the present paper results of the possibility of biosurfactant (Emulsan production by microorganisms isolated from Iranian oil reservoirs is presented. Fourthy three gram negative and gram positive, non fermentative, rod bacilli and coccobacilli shaped baceria were isolated from the oil wells of Bibi Hakimeh, Siri, Maroon, Ilam , East Paydar and West Paydar. Out of the isolated strains, 39 bacterial strains showed beta haemolytic activity, further screening revealed the emulsifying activity and surface tension. 11 out of 43 tested emulsifiers were identified as possible biosurfactant producers and two isolates produced large surface tension reduction, indicating the high probability of biosurfactant production. Further investigation revealed that, two gram negative, oxidase negative, aerobic and coccoid rods isolates were the best producers and hence designated as IL-1, PAY-4. Whole culture broth of isolates reduced surface tension from 68 mN /m to 30 and 29.1mN/m, respectively, and were stable during exposure to high salinity (10%NaCl and elevated temperatures(120C for 15 min .

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

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    Sobhan Ghafourian

    2014-07-01

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

  7. The Acinetobacter baumannii Oxymoron: Commensal Hospital Dweller Turned Pan-Drug-Resistant Menace

    Science.gov (United States)

    Roca, Ignasi; Espinal, Paula; Vila-Farrés, Xavier; Vila, Jordi

    2012-01-01

    During the past few decades Acinetobacter baumannii has evolved from being a commensal dweller of health-care facilities to constitute one of the most annoying pathogens responsible for hospitalary outbreaks and it is currently considered one of the most important nosocomial pathogens. In a prevalence study of infections in intensive care units conducted among 75 countries of the five continents, this microorganism was found to be the fifth most common pathogen. Two main features contribute to the success of A. baumannii: (i) A. baumannii exhibits an outstanding ability to accumulate a great variety of resistance mechanisms acquired by different mechanisms, either mutations or acquisition of genetic elements such as plasmids, integrons, transposons, or resistant islands, making this microorganism multi- or pan-drug-resistant and (ii) The ability to survive in the environment during prolonged periods of time which, combined with its innate resistance to desiccation and disinfectants, makes A. baumannii almost impossible to eradicate from the clinical setting. In addition, its ability to produce biofilm greatly contributes to both persistence and resistance. In this review, the pathogenesis of the infections caused by this microorganism as well as the molecular bases of antibacterial resistance and clinical aspects such as treatment and potential future therapeutic strategies are discussed in depth. PMID:22536199

  8. Molecular detection of aminoglycoside-modifying enzyme genes in Acinetobacter baumannii clinical isolates.

    Science.gov (United States)

    Heidary, Mohsen; Salimi Chirani, Alireza; Khoshnood, Saeed; Eslami, Gita; Atyabi, Seyyed Mohammad; Nazem, Habibollah; Fazilati, Mohammad; Hashemi, Ali; Soleimani, Saleh

    2017-06-01

    Acinetobacter baumannii is a major opportunistic pathogen in healthcare settings worldwide. In Iran, there are only few reports on the prevalence of aminoglycoside resistance genes among A. baumannii isolates. The aim of this study was to investigate the existence of aminoglycoside-modifying enzyme (AME) genes from A. baumannii strains collected at a university teaching hospital in Iran. One hundred A. baumannii strains were collected between 2014 and 2015 from hospitalized patients at Loghman Hakim Hospital, Tehran, Iran. Antimicrobial susceptibility was determined by disk diffusion method according to the Clinical and Laboratory Standards Institute recommendations. The DNA was extracted using a kit obtained from Bioneer Co. (Korea) and was used as a template for polymerase chain reaction. The most active antimicrobial agent against these strains was colistin. The rate of extended-spectrum cephalosporin resistance was 97%. The aadA1, aadB, aac(6')-Ib, and aac(3)-IIa genes were found in 85%, 77%, 72%, and 68% of A. baumannii isolates, respectively. This study showed a high prevalence rate of AME genes in A. baumannii. This prevalence rate has explained that further aminoglycoside resistance genes may have role in the resistance of clinical isolates of A. baumannii. Therefore, control and treatment of serious infections caused by this opportunistic pathogen should be given more consideration.

  9. Variation in the OC locus of Acinetobacter baumannii genomes predicts extensive structural diversity in the lipooligosaccharide.

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    Johanna J Kenyon

    Full Text Available Lipooligosaccharide (LOS is a complex surface structure that is linked to many pathogenic properties of Acinetobacter baumannii. In A. baumannii, the genes responsible for the synthesis of the outer core (OC component of the LOS are located between ilvE and aspS. The content of the OC locus is usually variable within a species, and examination of 6 complete and 227 draft A. baumannii genome sequences available in GenBank non-redundant and Whole Genome Shotgun databases revealed nine distinct new types, OCL4-OCL12, in addition to the three known ones. The twelve gene clusters fell into two distinct groups, designated Group A and Group B, based on similarities in the genes present. OCL6 (Group B was unique in that it included genes for the synthesis of L-Rhamnosep. Genetic exchange of the different configurations between strains has occurred as some OC forms were found in several different sequence types (STs. OCL1 (Group A was the most widely distributed being present in 18 STs, and OCL6 was found in 16 STs. Variation within clones was also observed, with more than one OC locus type found in the two globally disseminated clones, GC1 and GC2, that include the majority of multiply antibiotic resistant isolates. OCL1 was the most abundant gene cluster in both GC1 and GC2 genomes but GC1 isolates also carried OCL2, OCL3 or OCL5, and OCL3 was also present in GC2. As replacement of the OC locus in the major global clones indicates the presence of sub-lineages, a PCR typing scheme was developed to rapidly distinguish Group A and Group B types, and to distinguish the specific forms found in GC1 and GC2 isolates.

  10. Comparative pharmacodynamics of four different carbapenems in combination with polymyxin B against carbapenem-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Lenhard, Justin R; Gall, Jonathan S; Bulitta, Jurgen B; Thamlikitkul, Visanu; Landersdorfer, Cornelia B; Forrest, Alan; Nation, Roger L; Li, Jian; Tsuji, Brian T

    2016-12-01

    The objective of this study was to determine the comparative pharmacodynamics of four different carbapenems in combination with polymyxin B (PMB) against carbapenem-resistant Acinetobacter baumannii isolates using time-kill experiments at two different inocula. Two A. baumannii strains (03-149-1 and N16870) with carbapenem minimum inhibitory concentrations (MICs) ranging from 8 to 64 mg/L were investigated in 48-h time-kill experiments using starting inocula of 10 6  CFU/mL and 10 8  CFU/mL. Concentration arrays of ertapenem, doripenem, meropenem and imipenem at 0.25×, 0.5×, 1×, 1.5× and 2× published maximum serum concentration (C max ) values (C max concentrations of 12, 21, 48 and 60 mg/L, respectively) were investigated in the presence of 1.5 mg/L PMB. Use of carbapenems without PMB resulted in drastic re-growth. All carbapenem combinations were able to achieve a ≥3 log 10 CFU/mL reduction by 4 h against both strains at 10 6  CFU/mL, whereas maximum reductions against strain 03-149-1 at 10 8  CFU/mL were 1.0, 3.2, 2.2 and 3.3 log 10 CFU/mL for ertapenem, doripenem, meropenem and imipenem, respectively. None of the combinations were capable of reducing 10 8  CFU/mL of N16870 by ≥2 log 10 CFU/mL. Ertapenem combinations consistently displayed the least activity, whereas doripenem, meropenem and imipenem combinations had similar activities that were poorly predicted by carbapenem MICs. As doripenem, meropenem, or imipenem displayed similar pharmacodyanmics in combination, the decision of which carbapenem to use in combination with PMB may be based on toxicodynamic profiles if drastic discordance in MICs is not present. Copyright © 2016. Published by Elsevier B.V.

  11. Emergence in Taiwan of novel imipenem-resistant Acinetobacter baumannii ST455 causing bloodstream infection in critical patients.

    Science.gov (United States)

    Lee, Hao-Yuan; Huang, Chih-Wei; Chen, Chyi-Liang; Wang, Yi-Hsin; Chang, Chee-Jen; Chiu, Cheng-Hsun

    2015-12-01

    Acinetobacter baumannii is one of the most important nosocomial pathogens worldwide. This study aimed to use multilocus sequence typing (MLST) for the epidemiological surveillance of A. baumannii isolates in Taiwan and analyze the clinical presentations and patients' outcome. MLST according to both Bartual's PubMLST and Pasteur's MLST schemes was applied to characterize bloodstream imipenem-resistant A. baumannii (IRAB) infection in intensive care units in a medical center. A total of 39 clinical IRAB bloodstream isolates in 2010 were enrolled. We also collected 13 imipenem-susceptible A. baumannii (ISAB) bloodstream isolates and 30 clinical sputum isolates (24 IRAB and 6 ISAB) for comparison. Clinical presentations and outcome of the patients were analyzed. We found that infection by ST455(B)/ST2(P) and inappropriate initial therapy were statistically significant risk factors for mortality. More than one-third of the IRAB isolates belonged to ST455(B)/ST2(P). Most ST455(B)/ST2(P) (80%) carried ISAba1-blaOXA-23, including 10 (66.7%) with Tn2006 (ISAba1-blaOXA-23-ISAba1) in an AbaR4-type resistance island. ST455(B)/ST2(P) appears to evolve from ST208(B)/ST2(P) of clonal complex (CC) 92(B)/CC2(P). In this hospital-based study, A. baumannii ST455 accounted for 38.5% of IRAB bacteremia, with a high mortality of 86.7%. Approximately 85% of ST455(B)/ST2(P)bacteremia had a primary source of ventilation-associated pneumonia. We report the emergence in Taiwan of IRAB ST455(B)/ST2(P), which is the current predominant clone of IRAB in our hospital and has been causing bacteremia with high mortality in critical patients. Copyright © 2015. Published by Elsevier B.V.

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

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    Wenjuan Wei

    2017-12-01

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

  13. Effects of alpha-zirconium phosphate on thermal degradation and flame retardancy of transparent intumescent fire protective coating

    International Nuclear Information System (INIS)

    Xing, Weiyi; Zhang, Ping; Song, Lei; Wang, Xin; Hu, Yuan

    2014-01-01

    Graphical abstract: - Highlights: • A transparent intumescent fire protective coating was obtained by UV-cured technology. • OZrP could enhance the thermal stability and anti-oxidation of the coating. • OZrP could reduce the combustion properties of t