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Sample records for acinetobacter sp bd413

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

    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.)

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  5. 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.

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

    Indian Academy of Sciences (India)

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

    2012-12-01

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

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

    Science.gov (United States)

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

    2012-01-01

    One of the most serious diseases in potato cultivars is caused by the pathogen Phytophthora infestans, which affects leaves, stems and tubers. Metalaxyl is a fungicide that protects potato plants from Phytophthora infestans. In Mexico, farmers apply metalaxyl 35 times during the cycle of potato production and the last application is typically 15 days before harvest. There are no records related to the presence of metalaxyl in potato tubers in Mexico. In the present study, we evaluated the effect of Acinetobacter sp on metalaxyl degradation in potato seedlings. The effect of bacteria and metalaxyl on the growth of potato seedlings was also evaluated. A metabolite profile analysis was conducted to determine potential molecular biomarkers produced by potato seedlings in the presence of Acinetobacter sp and metalaxyl. Metalaxyl did not affect the growth of potato seedlings. However, Acinetobacter sp strongly affected the growth of inoculated seedlings, as confirmed by plant length and plant fresh weights which were lower in inoculated potato seedlings (40% and 27%, respectively) compared to the controls. Acinetobacter sp also affected root formation. Inoculated potato seedlings showed a decrease in root formation compared to the controls. LC-MS/MS analysis of metalaxyl residues in potato seedlings suggests that Acinetobacter sp did not degrade metalaxyl. GC–TOF–MS platform was used in metabolic profiling studies. Statistical data analysis and metabolic pathway analysis allowed suggesting the alteration of metabolic pathways by both Acinetobacter sp infection and metalaxyl treatment. Several hundred metabolites were detected, 137 metabolites were identified and 15 metabolic markers were suggested based on statistical change significance found with PLS-DA analysis. These results are important for better understanding the interactions of putative endophytic bacteria and pesticides on plants and their possible effects on plant metabolism. PMID:22363586

  8. 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.

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

    Science.gov (United States)

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

    2012-01-01

    One of the most serious diseases in potato cultivars is caused by the pathogen Phytophthora infestans, which affects leaves, stems and tubers. Metalaxyl is a fungicide that protects potato plants from Phytophthora infestans. In Mexico, farmers apply metalaxyl 35 times during the cycle of potato production and the last application is typically 15 days before harvest. There are no records related to the presence of metalaxyl in potato tubers in Mexico. In the present study, we evaluated the effect of Acinetobacter sp on metalaxyl degradation in potato seedlings. The effect of bacteria and metalaxyl on the growth of potato seedlings was also evaluated. A metabolite profile analysis was conducted to determine potential molecular biomarkers produced by potato seedlings in the presence of Acinetobacter sp and metalaxyl. Metalaxyl did not affect the growth of potato seedlings. However, Acinetobacter sp strongly affected the growth of inoculated seedlings, as confirmed by plant length and plant fresh weights which were lower in inoculated potato seedlings (40% and 27%, respectively) compared to the controls. Acinetobacter sp also affected root formation. Inoculated potato seedlings showed a decrease in root formation compared to the controls. LC-MS/MS analysis of metalaxyl residues in potato seedlings suggests that Acinetobacter sp did not degrade metalaxyl. GC-TOF-MS platform was used in metabolic profiling studies. Statistical data analysis and metabolic pathway analysis allowed suggesting the alteration of metabolic pathways by both Acinetobacter sp infection and metalaxyl treatment. Several hundred metabolites were detected, 137 metabolites were identified and 15 metabolic markers were suggested based on statistical change significance found with PLS-DA analysis. These results are important for better understanding the interactions of putative endophytic bacteria and pesticides on plants and their possible effects on plant metabolism. PMID:22363586

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

    Science.gov (United States)

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

    2015-11-01

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

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

    Science.gov (United States)

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

    2012-09-01

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

  12. Biodegradation of phenol by using free and immobilized cells of Acinetobacter sp. BS8Y.

    Science.gov (United States)

    Jiang, Lichun; Ruan, Qiping; Li, Rulan; Li, Tiandong

    2013-03-01

    Strain BS8Y with high biodegradation activity and high tolerance of phenol was isolated from activated sludge in an insulating material plant of China. This strain was capable of removing 99.2% of the initial 600 mg/l phenol in liquid minimal medium within 24 h and tolerating phenol at concentrations of up to 1,200 mg/ml. DNA sequencing and homologous analysis of the 16S rRNA gene identified that the strain BS8Y belonged to an Acinetobacter species. Polyvinyl alcohol was used as gel matrix to immobilize the strain BS8Y. The factors affecting the phenol degradation by immobilized cells and the phenol removal efficiency of free and immobilized cells were investigated; the stability of the immobilized cells is also reported. The results show that the immobilized cells could tolerate a higher phenol level and protected the bacteria much more effectively against changes in temperature and pH. The phenol degradation efficiency was high at up to 96% within 30 h, with an initial concentration of 800 mg/l phenol, and the immobilized cells showed better performance than the suspended cells. Reusability tests revealed that the immobilized cells were stable enough even after reuse for ten times or storing at 4°C for 35 d. These results demonstrate that immobilized Acinetobacter sp. BS8Y possesses a good application potential in the treatment of phenol-containing wastewater.

  13. Optimization of Fermentation Medium for the Production of Atrazine Degrading Strain Acinetobacter sp. DNS32 by Statistical Analysis System

    Directory of Open Access Journals (Sweden)

    Ying Zhang

    2012-01-01

    Full Text Available Statistical experimental designs provided by statistical analysis system (SAS software were applied to optimize the fermentation medium composition for the production of atrazine-degrading Acinetobacter sp. DNS32 in shake-flask cultures. A “Plackett-Burman Design” was employed to evaluate the effects of different components in the medium. The concentrations of corn flour, soybean flour, and K2HPO4 were found to significantly influence Acinetobacter sp. DNS32 production. The steepest ascent method was employed to determine the optimal regions of these three significant factors. Then, these three factors were optimized using central composite design of “response surface methodology.” The optimized fermentation medium composition was composed as follows (g/L: corn flour 39.49, soybean flour 25.64, CaCO3 3, K2HPO4 3.27, MgSO4 ·7H2O 0.2, and NaCl 0.2. The predicted and verifiable values in the medium with optimized concentration of components in shake flasks experiments were 7.079×108 CFU/mL and 7.194×108 CFU/mL, respectively. The validated model can precisely predict the growth of atrazine-degraing bacterium, Acinetobacter sp. DNS32.

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

    Science.gov (United States)

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

    2007-01-01

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

  15. 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.

  16. Production and characterization of L-fucose dehydrogenase from newly isolated Acinetobacter sp. strain SA-134.

    Science.gov (United States)

    Ohshiro, Takashi; Morita, Noriyuki

    2014-01-01

    Microorganisms producing L-fucose dehydrogenase were screened from soil samples, and one of the isolated bacterial strains SA-134 was identified as Acinetobacter sp. by 16S rDNA gene analysis. The strain grew well utilizing L-fucose as a sole source of carbon, but all other monosaccharides tested such as D-glucose and D-arabinose did not support the growth of the strain in the absence of L-fucose. D-Arabinose inhibited the growth even in the culture medium containing L-fucose. Although the strain grew on some organic acids and amino acids such as citric acid and L-alanine as sole sources of carbon, the enzyme was produced only in the presence of L-fucose. The fucose dehydrogenase was purified to apparently homogeneity from the strain, and the native enzyme was a monomer of 25 kD. L-Fucose and D-arabinose were good substrates for the enzyme, but L-galactose was a poor substrate. The enzyme acted on both NAD(+) and NADP(+) in the similar manner.

  17. Characterization of a fluoride-resistant bacterium Acinetobacter sp. RH5 towards assessment of its water defluoridation capability

    Science.gov (United States)

    Mukherjee, Shraboni; Yadav, Vaibhav; Mondal, Madhumanti; Banerjee, Soumya; Halder, Gopinath

    2015-12-01

    The present study investigates the defluoridation capability of fluoride-resistant bacteria from contaminated groundwater collected from Asanjola and Madhabpur, West Bengal, India. Seven strains of fluoride-resistant bacteria were isolated employing culture media containing 10-250 mg/L of fluoride to evaluate their ability in reducing fluoride concentration in water. Five isolates exhibited significant amount of reduction in fluoride. Isolate RH5 achieved a maximum fluoride removal of 25.7 % from the media at 30 °C and pH 7 after 8 days of incubation. Based on morphological, physiological characteristics and analysis of 16S rDNA gene sequence, isolate RH5 was identified as Acinetobacter sp. RH5. Growth of RH5 was analysed at a diverse pH range, and it could thrive at pH 5-10. The present investigation revealed that the selective pressure of fluoride results in growth of fluoride-resistant bacteria capable of secreting high-affinity anion-binding compounds. This bacterium played a dominant bioremediative role by concentrating the anions so that they become less available. Hence, the fluoride-resistant bacteria, Acinetobacter sp. RH5, could be used as a promising strain for application in water defluoridation from contaminated sites.

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

    Science.gov (United States)

    Gospodarek, E

    1993-01-01

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

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

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    Amro Abd Al Fattah Amara

    2010-05-01

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

  20. 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. PMID:25954258

  1. 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.

  2. Vitroprocines, new antibiotics against Acinetobacter baumannii, discovered from marine Vibrio sp. QWI-06 using mass-spectrometry-based metabolomics approach

    Science.gov (United States)

    Liaw, Chih-Chuang; Chen, Pei-Chin; Shih, Chao-Jen; Tseng, Sung-Pin; Lai, Ying-Mi; Hsu, Chi-Hsin; Dorrestein, Pieter C.; Yang, Yu-Liang

    2015-08-01

    A robust and convenient research strategy integrating state-of-the-art analytical techniques is needed to efficiently discover novel compounds from marine microbial resources. In this study, we identified a series of amino-polyketide derivatives, vitroprocines A-J, from the marine bacterium Vibrio sp. QWI-06 by an integrated approach using imaging mass spectroscopy and molecular networking, as well as conventional bioactivity-guided fractionation and isolation. The structure-activity relationship of vitroprocines against Acinetobacter baumannii is proposed. In addition, feeding experiments with 13C-labeled precursors indicated that a pyridoxal 5‧-phosphate-dependent mechanism is involved in the biosynthesis of vitroprocines. Elucidation of amino-polyketide derivatives from a species of marine bacteria for the first time demonstrates the potential of this integrated metabolomics approach to uncover marine bacterial biodiversity.

  3. 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.

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

    Science.gov (United States)

    Lin, J; Milase, R N

    2015-12-01

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

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

    Science.gov (United States)

    Lin, J; Milase, R N

    2015-12-01

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

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

    Science.gov (United States)

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

    2016-08-15

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

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

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

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

    OpenAIRE

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

    2008-01-01

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

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

    OpenAIRE

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

    2011-01-01

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

  10. Isolation of an Entophyte Acinetobacter sp. from Cowpea Flowers%一株豇豆花苞内生不动杆菌的分离鉴定

    Institute of Scientific and Technical Information of China (English)

    韩雪; 熊燕妮; 江瑞晶; 曾辰; 陈禅友

    2015-01-01

    The entophyte bacteria(wjhb)was isolated from the cowpea flowers in Wuhan ,which was the dominant strain in the cowpea florescence. The proper temperature range for the entophyte bacteria culture was 16~43℃and the Gram staining result was negative. The biochemical experiment result showed the entophyte bacteria belonged to Acinetobacter sp. and the biochemical character was up to the Acinetobacter sp. The 16SrDNA sequence PCR results showed the similarity of 16SrDNA sequence with Acinetobacter sp. reached 98%. The entophyte Acinetobacter sp.(wjhb)in this paper was an ideal candidate of the host for cowpea engineered bio-control bacteria.%从武汉豇豆种植基地的豇豆花苞中筛选出花内生菌(命名为wjhb),其在豇豆花苞中大量存在,在花瓣中为优势内生菌。染色鉴定为革兰氏阴性杆菌,可以在16~43℃温度生长;生化试验显示,该菌生化特征符合不动杆菌特征;16SrDNA扩增产物测序后,经软件分析其16SrDNA序列为与不动杆菌序列相似度达98%。本试验分离得到的内生不动杆菌(wjhb),有望成为豇豆基因工程生防菌的理想宿主菌株。

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

    Directory of Open Access Journals (Sweden)

    M Farzadkia

    2009-11-01

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

  12. Biodegradation of Azo Dye Disperse Orange S-RL by a Newly Isolated Strain Acinetobacter sp. SRL8.

    Science.gov (United States)

    Cai, Zhiqiang; Zhang, Wenjie; Ma, Jiangtao; Cai, Jinyan; Li, Shanshan; Zhu, Xiaolin; Yang, Guanghua; Zhao, Xiyue

    2015-06-01

    The strain SRL8, which could decolorize the azo dye disperse orange S-RL (S-RL), was first isolated from sludge and identified as Acinetobacter sp. through physiobiochemical identification and 16S rRNA gene sequences. The effects of temperature, pH, dye concentration, O2, and glucose concentration on S-RL decolorization by the strain SRL8 were studied. The optimal conditions were 30 °C, pH 7.0, 4g·L(-1) of inoculation (wet cells), and microaerophilic incubation. The decolorization percentage for S-RL by the strain SRL8 could reach 90.2% under optimal conditions. The strain SRL8 was highly tolerant to the azo dye SRL up to 300 mg·L(-1) and it had a broad decolorizing spectrum. According to the Monod equation, kinetic parameters of decolorization by SRL8 were calculated. The vmax and Km were 5.57×10(-3) h(-1) and 14.53 mg·L(-1), respectively.

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

    Directory of Open Access Journals (Sweden)

    Masahito Ishikawa

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

    The purpose of this study was to isolate, purify and optimize the production conditions of an organic solvent tolerant and thermostable lipase from Acinetobacter sp. AU07 isolated from distillery waste. The lipase production was optimized by response surface methodology, and a maximum production of 14.5U/mL was observed at 30°C and pH 7, using a 0.5% (v/v) inoculum, 2% (v/v) castor oil (inducer), and agitation 150rpm. The optimized conditions from the shake flask experiments were validated in a 3L lab scale bioreactor, and the lipase production increased to 48U/mL. The enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography and the overall yield was 36%. SDS-PAGE indicated a molecular weight of 45kDa for the purified protein, and Matrix assisted laser desorption/ionization time of flight analysis of the purified lipase showed sequence similarity with GDSL family of lipases. The optimum temperature and pH for activity of the enzyme was found to be 50°C and 8.0, respectively. The lipase was completely inhibited by phenylmethylsulfonyl fluoride but minimal inhibition was observed when incubated with ethylenediaminetetraacetic acid and dithiothreitol. The enzyme was stable in the presence of non-polar hydrophobic solvents. Detergents like SDS inhibited enzyme activity; however, there was minimal loss of enzyme activity when incubated with hydrogen peroxide, Tween 80 and Triton X-100. The kinetic constants (Km and Vmax) revealed that the hydrolytic activity of the lipase was specific to moderate chain fatty acid esters. The Vmax, Km and Vmax/Km ratio of the enzyme were 16.98U/mg, 0.51mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate. PMID:27268114

  17. 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.

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

    OpenAIRE

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

    2011-01-01

    INTRODUÇÃO: O principal mecanismo de resistência entre isolados de Pseudomonas aeruginosa e Acinetobacter sp. é a produção de metalo-β-lactamases (MβLs). As MβLs são enzimas capazes de hidrolisar cefalosporinas, penicilinas e carbapenêmicos, mas não monobactâmicos (aztreonam) antibióticos que se encontram entre as principais opções terapêuticas para o tratamento de infecções causadas por bactérias não fermentadoras de glicose. MÉTODOS: Um estudo observacional, transversal, descritivo e retros...

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

    OpenAIRE

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

    2011-01-01

    INTRODUÇÃO: O principal mecanismo de resistência entre isolados de Pseudomonas aeruginosa e Acinetobacter sp. é a produção de metalo-β-lactamases (MβLs). As MβLs são enzimas capazes de hidrolisar cefalosporinas, penicilinas e carbapenêmicos, mas não monobactâmicos (aztreonam) antibióticos que se encontram entre as principais opções terapêuticas para o tratamento de infecções causadas por bactérias não fermentadoras de glicose. MÉTODOS: Um estudo observacional, transversal, desc...

  20. Role of Feed Forward Neural Networks Coupled with Genetic Algorithm in Capitalizing of Intracellular Alpha-Galactosidase Production by Acinetobacter sp.

    Directory of Open Access Journals (Sweden)

    Sirisha Edupuganti

    2014-01-01

    Full Text Available Alpha-galactosidase production in submerged fermentation by Acinetobacter sp. was optimized using feed forward neural networks and genetic algorithm (FFNN-GA. Six different parameters, pH, temperature, agitation speed, carbon source (raffinose, nitrogen source (tryptone, and K2HPO4, were chosen and used to construct 6-10-1 topology of feed forward neural network to study interactions between fermentation parameters and enzyme yield. The predicted values were further optimized by genetic algorithm (GA. The predictability of neural networks was further analysed by using mean squared error (MSE, root mean squared error (RMSE, mean absolute error (MAE, mean absolute percentage error (MAPE, and R2-value for training and testing data. Using hybrid neural networks and genetic algorithm, alpha-galactosidase production was improved from 7.5 U/mL to 10.2 U/mL.

  1. Biodegradation of type II pyrethroids and major degraded products by a newly isolated Acinetobacter sp. strain JN8.

    Science.gov (United States)

    Jin, Zhaoxia; Guo, Qiong; Zhang, Zongshen; Yan, Tongshuai

    2014-08-01

    A Gram-negative aerobic bacterium, designated as JN8, was isolated from activated sludge and soil in a pesticides factory in China. It was found that JN8 had a high capacity for degrading a broad range of type II pyrethroids and utilizing these pyrethroids as the sole carbon source for cell growth. The degradation rates of a 100 mg·L(-1) concentration of β-cypermethrin, cypermethrin, fenpropathrin, fenvalerate, and deltamethrin by JN8 in mineral salt medium were 74.1%, 64.9%, 57.9%, 48.1% and 34.9%, respectively. Strain JN8 was identified as a species of Acinetobacter based on its biochemical properties and 16S rRNA sequence analysis. β-Cypermethrin was degraded by JN8 through hydrolysis of the carboxylester linkage to form 3-phenoxybenzoic acid and 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, both of which could be further degraded by JN8. JN8 is the first strain of an Acinetobacter species in which pyrethoid-degrading activity has been detected, and such a feature makes it a potential resource for disposal of waste and effluent from pyrethroid manufacturing facilities.

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

    DEFF Research Database (Denmark)

    Hansen, Susse Kirkelund; Haagensen, Janus Anders Juul; Gjermansen, Morten;

    2007-01-01

    to oxygen starvation. A key factor explaining this conditional, nondispersal phenotype is likely to be the acquired ability of the rough variant to coaggregate specifically with Acinetobacter cells. We further show that the P. putida rough variant displayed enhanced production of a cellulose-like polymer......Genetic differentiation by natural selection is readily observed among microbial populations, but a more comprehensive understanding of evolutionary forces, genetic causes, and resulting phenotypic advantages is not often sought. Recently, a surface population of Pseudomonas putida bacteria....... putida wild-type cells, which readily dispersed from the mixed-species biofilm in response to oxygen starvation, the rough variant cells displayed a nondispersal phenotype. However, in monospecies biofilms proliferating on benzoate, the rough variant (like the wild-type population) dispersed in response...

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  5. 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. Moreover

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

    Directory of Open Access Journals (Sweden)

    Anahita Khoramnia

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Kozińska Alicja

    2014-06-01

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

  8. 不动杆菌D10对土壤中对硫磷的降解%Biodegradation of Parathion in Soil by Acinetobacter sp. D10

    Institute of Scientific and Technical Information of China (English)

    姜莉; 史艳芳; 刘鑫; 李志明; 张雪雨; 姜彬慧

    2011-01-01

    Organophosphorus pesticides are worldwide widely used to control agrieultural and household pests. Ovenall.organophosphorus compounds account for the 38% of total pesticides used globally. Parathion is a virulent organophate insecticide with perfect insecticidal effciency. However. it is also highly toxic and harmful to human and other creatures.In order to investigae mierobial remediation of soil potluted by pesticides, a strain D10 of parathion-degrading is obtained by selective enrichment culture from the pesticides-contaminated soil.Parathion could be used by D1O as a sole carbon source. D10 is identified as Acinetobacter sp. based on the morpho1ogical. physiochemical characters and 16S rDNA sequence analyses. The optimal growth temperature for D1O in shaking flasks is 28℃, and the optimal pH is 6.0-7.0. The optimal carbon and nitrogen source are sodium citrate and yeast powser.respectively. D1O grows fast and reaches at the maximum biomass after 24 hours incubation in nutrient medium. The D1O-degradation rate of parathion is determined by using the Gas Chromatography (GC). and is 83.1% after 24 hours. The bio-degradation rate of parathion in simulated and sterilized contamination soils with 100 mg·kg-1 parathion concentration reaches at 66.7% after seven days inoulafion. The result shows that the D1O has a great practical value in the remediation of contaminated soils by parathion.%为了考查微生物对农药污染土壤的修复作用,本文从受农药污染的土壤中筛选出一株对对硫磷有降解作用的菌株D10.采用室内培养方法.根据其形态特征、生理生化特性和16S rDNA序列分析,鉴定D10为不动杆菌属(Acinetobacter sp.)的微生物.通过分光光度比浊法研究其最佳生长条件.结果表明,D10的最佳生长温度为28℃,最佳培养初始pH值为6.0-7.0.D10生长周期较短,在营养培养基中培养24h就可达到最大生物量,其培养的最佳C、N源.分别为柠檬酸钠和酵母粉.利

  9. Biofilm formation and biocide resistance of acinetobacter baumannii

    OpenAIRE

    Shoukat, Kamran

    2014-01-01

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

  10. 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.

  11. 不动杆菌3-苯氧基苯甲酸降解基因的克隆与表达%Cloning and Expression of 3-Phenoxybenzoic Acid Biodegrading Gene from Acinetobacter sp

    Institute of Scientific and Technical Information of China (English)

    梁俊仕; 许雷

    2015-01-01

    3-Phenoxybenzoic acid ( 3-PBA) is known as non-specific intermediate products of pyrethriods pesticide, which has antiestrogenic activity, and can disturb the endocrine system in vivo. 3-PBA has wider migration, longer half-life period, and higher biotoxicity than the pyrethroid pesticide, so it has been used as a marker for pyrethroids exposure. With the contruction and screening of 4-D(Acinetobacter sp.) genomic library, the key gene having a ORF of 921 bp and encoding an amino acid of 306 aa for degrading 3-PBA was screened, its GenBank accession number was KR024742. Homolog comparison results and substrate experiments inferred that it was catechol dioxygenase. The primer was designed on the authority of opening reading frames( ORF) and added with restriction sites of NdeⅠ and HindⅢ. With genomic DNA of 4-D as template, the D34 gene was cloned. The recombinant expression vector pET-21b-D34 plasmid was constructed and transformed into competent cell BL21 (DE3). After inducing by IPTG(0.1 mmol/L), the degration rate of 3-PBA was 18.7%. Results provided theory reference for microbial environmental restoration of 3-PBA population.%3-苯氧基苯甲酸(3-PBA)作为拟除虫菊酯类农药的非特异性降解中间产物,具有抗雌激素特性,可扰乱生物体内分泌系统,比菊酯类农药迁移更广,半衰期更长,生物毒性更大,是拟除虫菊酯类农药在生物体中暴露的标志。通过构建4-D菌(Acinetobacter sp.)基因组文库,混合池驯化筛选得到4-D 菌中降解3-PBA 的关键酶基因,其开放阅读框为921 bp,编码306个氨基酸,Genbank登录号为KR024742。经同源比对和酶活验证,证实该酶为邻苯二酚双加氧酶。根据该ORF序列设计引物,引物两端分别加上NdeⅠ和Hind Ⅲ酶切位点,以4-D菌基因组DNA为模板,成功克隆到D34基因序列。构建表达载体pET-21b-D34并转化进宿主大肠杆菌BL21(DE3),经IPTG(0.1 mmol/L)

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

    Science.gov (United States)

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

    2015-01-01

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

  13. Ribotyping of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex.

    OpenAIRE

    Gerner-Smidt, P

    1992-01-01

    The Acinetobacter calcoaceticus-Acinetobacter baumannii complex consists of four genotypically distinct but phenotypically very similar bacterial species or DNA groups: A. calcoaceticus (DNA group 1), A. baumannii (DNA group 2), unnamed DNA group 3 (P. J. M. Bouvet and P. A. D. Grimont, Int. J. Syst. Bacteriol. 36:228-240, 1986), and unnamed DNA group 13 (I. Tjernberg and J. Ursing, APMIS 97:595-605, 1989). Because strains in this complex cause nosocomial outbreaks, it is important to be able...

  14. 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 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.

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

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  16. Weigle Reactivation in Acinetobacter Calcoaceticus

    DEFF Research Database (Denmark)

    Berenstein, Dvora

    1982-01-01

    Weigle (W)-reactivation was demonstrated in Acinetobacter calcoaceticus for the UV-irra-diated lysogenic phage P78. The reactivation factor (survival of irradiated phage on irradiated bacteria/ survival on unirradiated bacteria) reached a maximum value of 20. This was obtained at UV-doses giving ...

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

    Science.gov (United States)

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

    2016-06-01

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

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

    NARCIS (Netherlands)

    VANDERMEI, HC; COWAN, MM; BUSSCHER, HJ

    1991-01-01

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

  19. A case of disseminated intravascular coagulation secondary to Acinetobacter lwoffii and Acinetobacter baumannii bacteremia

    Directory of Open Access Journals (Sweden)

    Candice Baldeo

    2015-01-01

    Full Text Available Bacteremia is currently one of the infections with the highest mortality in hospitals [1]. Acinetobacter lwoffii and Acinetobacter baumannii are gram-negative bacteria and both represent opportunistic pathogens. In certain cases, the management can be challenging since these organisms can be highly resistant to antimicrobial agents. Clinical illnesses associated with Acinetobacter include pneumonia, meningitis, peritonitis, endocarditis and infections of the urinary tract and skin [1]. Acinetobacter bacteremia represents a serious and ever increasing problem because of the high associated morbidity and mortality.

  20. CARBAPENEM-RESISTANT ACINETOBACTER BAUMANII POSTOPERATIVE MENINGITIS

    Directory of Open Access Journals (Sweden)

    Laura Ghibu

    2011-02-01

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

  1. 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...

  2. Multi-drug resistant Acinetobacter ventilator-associated pneumonia

    OpenAIRE

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

    Introduction This study aims to determine the Acinetobacter sp clinical isolates frequency and its antibiotic susceptibility pattern by comparing results obtained from the Intensive Care Units (ICUs) to that of other units at the Mohammed V Military Teaching Hospital in Rabat. Methods This is a retrospective study over a 2-years period where we collected all clinical isolates of Acinetobacter sp obtained from samples for infection diagnosis performed on hospitalized patients between 2012 to 2014. Results During the study period, 441 clinical and non-repetitive isolates of Acinetobacter sp were collected representing 6.94% of all bacterial clinical isolates (n = 6352) and 9.6% of Gram negative rods (n = 4569). More than a half of the isolates were from the ICUs and were obtained from 293 infected patients of which 65, 2% (191 cases) were males (sex ratio = 1.9) and the median age was 56 years (interquartile range: 42-68 years). Acinetobacter clinical isolates were obtained from respiratory samples (44.67%) followed by blood cultures (14.51%). The resistance to ciprofloxacin, ceftazidime, piperacillin / tazobactam, imipenem, amikacin, tobramycin, netilmicin, rifampicin and colistin was respectively 87%, 86%, 79%, 76%; 52%, 43%, 33% 32% and 1.7%. The difference in resistance between the ICUs and the other units was statistically significant (p <0.05) except for colistin, tetracycline and rifampicin. Conclusion This paper shows that solving the problem of prevalence and high rate of multidrug resistant Acinetobacter infection which represents a therapeutic impasse, requires the control of the hospital environment and optimizing hands hygiene and antibiotics use in the hospital. PMID:27347280

  4. NOSOCOMIAL ACINETOBACTER INFECTIONS IN INTENSIVE CARE UNIT

    Directory of Open Access Journals (Sweden)

    Nwadike V. Ugochukwu

    2013-01-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  6. 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

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

    OpenAIRE

    Shogo Yoshimoto; Hajime Nakatani; Keita Iwasaki; Katsutoshi Hori

    2016-01-01

    Trimeric autotransporter adhesins (TAAs), cell surface proteins of Gram-negative bacteria, mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific, high adhesiveness to abiotic material surfaces as well as to biotic surfaces. AtaA is a homotrimer of polypeptides comprising 3,630 amino acids and forms long nanofibers; therefore, it is too large and structurally complex to be produced...

  8. Phosphate uptake kinetics by Acinetobacter isolates.

    Science.gov (United States)

    Pauli, A S; Kaitala, S

    1997-02-01

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

  9. Antimicrobial resistance and clonality in Acinetobacter baumannii

    OpenAIRE

    Nemec, Alexandr

    2009-01-01

    The aim of this thesis was to obtain insight into the epidemiology and molecular basis of multidrug resistance of Acinetobacter baumannii at the population level. To this aim a number of studies were performed on strains mainly from the Czech Republic (CR) which have shown in particular that (i) the vast majority of multidrug resistant (MDR) clinical isolates of A. baumannii from CR belong to clonal lineages termed EU clone I and II; (ii) these two clones have predominated among MDR hospital ...

  10. Mortality audit of neonatal sepsis secondary to Acinetobacter

    Directory of Open Access Journals (Sweden)

    Anuradha S De

    2013-01-01

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

  11. Development of immunization trials against Acinetobacter baumannii

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    Tarek A. Ahmad

    2016-01-01

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

  12. Multi-drug resistant Acinetobacter ventilator-associated pneumonia

    Directory of Open Access Journals (Sweden)

    Shete Vishal

    2010-01-01

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

  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. 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.

  15. Mortality audit of neonatal sepsis secondary to Acinetobacter

    OpenAIRE

    Anuradha S; Madhuri R Rathi; Mathur, Meenakshi M

    2013-01-01

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

  16. [Degradation of oil derivatives by Acinetobacter calcoaceticus MM5].

    Science.gov (United States)

    Marín, M M; Ortiz, M L; Laborda, F

    1994-01-01

    This paper describes the isolation of microorganisms from polluted heating oil. The growth of one of them has been studied (Acinetobacter calcoaceticus MM5) in several linear and branched hydrocarbons as well as the effect of its growth on commercial diesel oil. Acinetobacter calcoaceticus MM5 is not capable of using glucose as its only source of carbon, and it needs the presence of nitrogen and phosphorus sources to degrade any petroleum by-product.

  17. Improved homology model of cyclohexanone monooxygenase from Acinetobacter calcoaceticus based on multiple templates.

    Science.gov (United States)

    Bermúdez, Eduardo; Ventura, Oscar N; Eriksson, Leif A; Saenz-Méndez, Patricia

    2014-04-01

    A new homology model of cyclohexanone monooxygenase (CHMO) from Acinetobacter calcoaceticus is derived based on multiple templates, and in particular the crystal structure of CHMO from Rhodococcus sp. The derived model was fully evaluated, showing that the quality of the new structure was improved over previous models. Critically, the nicotinamide cofactor is included in the model for the first time. Analysis of several molecular dynamics snapshots of intermediates in the enzymatic mechanism led to a description of key residues for cofactor binding and intermediate stabilization during the reaction, in particular Arg327 and the well known conserved motif (FxGxxxHxxxW) in Baeyer-Villiger monooxygenases, in excellent agreement with known experimental and computational data.

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

    International Nuclear Information System (INIS)

    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)

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

    NARCIS (Netherlands)

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

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Multi-drug resistant Acinetobacter ventilator-associated pneumonia

    OpenAIRE

    Shete Vishal; Ghadage Dnyaneshwari; Muley Vrishali; Bhore Arvind

    2010-01-01

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

  2. Draft Genome Sequence of the Environmentally Isolated Acinetobacter pittii Strain IPK_TSA6.1

    Science.gov (United States)

    Lee, Yunmi

    2016-01-01

    Acinetobacter pittii is an opportunistic pathogen frequently isolated from Acinetobacter infections other than those from Acinetobacter baumannii. Multidrug resistance in A. pittii, including resistance to carbapenems, has been increasingly reported worldwide. Here, we report the 4.14-Mbp draft genome sequence of A. pittii IPK_TSA6.1 that was isolated from a nonhospital setting. PMID:27688336

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

    OpenAIRE

    Purti C Tripathi; Sunita R Gajbhiye; Gopal Nandlal Agrawal

    2014-01-01

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

  4. Draft Genome Sequence of the Environmentally Isolated Acinetobacter pittii Strain IPK_TSA6.1.

    Science.gov (United States)

    Lee, Yunmi; Jang, Soojin

    2016-01-01

    Acinetobacter pittii is an opportunistic pathogen frequently isolated from Acinetobacter infections other than those from Acinetobacter baumannii Multidrug resistance in A. pittii, including resistance to carbapenems, has been increasingly reported worldwide. Here, we report the 4.14-Mbp draft genome sequence of A. pittii IPK_TSA6.1 that was isolated from a nonhospital setting. PMID:27688336

  5. Iron and Acinetobacter baumannii Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Valentina Gentile

    2014-08-01

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

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

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    Chia-Ter Chao

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

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

    Science.gov (United States)

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

    2012-06-01

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

  8. Acinetobacter septicemia in neonates admitted to intensive care units

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    Vishal B Shete

    2009-01-01

    Results: A total of 26 Acinetobacter septicemia cases were identified by blood culture. Acb complex strains predominated. Institutional birth and preterm birth were identified as the most frequent significant risk factors. 11.3% mortality rate was recorded. Acb complex strains exhibited a multi-drug resistant pattern. No carbapenem resistance was observed. Conclusion: Acinetobacter should be added to the list of organisms causing severe nosocomial infection in neonatal intensive care units. Continuous bacteriological surveillance, implementation of infection control policies, careful disinfection of intensive care equipment, and rational antibiotic use are required for control of such infections.

  9. 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.

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

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    Johanna J Kenyon

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

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

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    Jong Suk Jin

    2011-12-01

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

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

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    Vânia Waleska Sousa da Cunha

    2015-01-01

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

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

    OpenAIRE

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

    2009-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    OpenAIRE

    Harun Aðca

    2013-01-01

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

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

    OpenAIRE

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

    1991-01-01

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

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

    OpenAIRE

    Rodríguez Méndez, Tatiana

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Harun Aðca

    2013-01-01

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

  19. Incidence of Acinetobacter species other than A. baumannii among clinical isolates of Acinetobacter: evidence for emerging species.

    Science.gov (United States)

    Turton, Jane F; Shah, Jayesh; Ozongwu, Chika; Pike, Rachel

    2010-04-01

    Six hundred ninety nonduplicate isolates of Acinetobacter species were identified using a combination of detection of bla(OXA-51-like) and rpoB sequence cluster analysis. Although most isolates were identified as A. baumannii (78%), significant numbers of other species, particularly A. lwoffii/genomic species 9 (8.8%), A. ursingii (4%), genomic species 3 (1.7%), and A. johnsonii (1.7%), were received, often associated with bacteremias.

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

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    Phatthalung Pinanong

    2012-04-01

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

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

    OpenAIRE

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

    2008-01-01

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

  2. Draft genome sequence of Acinetobacter pittii ST643 shared by cystic fibrosis patients

    Science.gov (United States)

    Rocha, Géssica A; Ferreira, Alex G; Lima, Danielle F; Leão, Robson S; Carvalho-Assef, Ana Paula D; Folescu, Tânia W; Albano, Rodolpho M; Marques, Elizabeth A

    2016-01-01

    Acinetobacter pittii has emerged as an important hospital pathogen that is associated with outbreaks and drug resistance. In cystic fibrosis (CF) patients, the detection of Acinetobacter spp. is rare; however, we isolated the A. pittii sequence type ST643 in several Brazilian CF patients treated in the same centre. The current study describes the draft genome of A. pittii ST643.

  3. Draft genome sequence of Acinetobacter pittii ST643 shared by cystic fibrosis patients.

    Science.gov (United States)

    Rocha, Géssica A; Ferreira, Alex G; Lima, Danielle F; Leão, Robson S; Carvalho-Assef, Ana Paula D; Folescu, Tânia W; Albano, Rodolpho M; Marques, Elizabeth A

    2016-09-01

    Acinetobacter pittii has emerged as an important hospital pathogen that is associated with outbreaks and drug resistance. In cystic fibrosis (CF) patients, the detection of Acinetobacter spp. is rare; however, we isolated the A. pittii sequence type ST643 in several Brazilian CF patients treated in the same centre. The current study describes the draft genome of A. pittii ST643. PMID:27653362

  4. Draft genome sequence of Acinetobacter pittii ST643 shared by cystic fibrosis patients

    Science.gov (United States)

    Rocha, Géssica A; Ferreira, Alex G; Lima, Danielle F; Leão, Robson S; Carvalho-Assef, Ana Paula D; Folescu, Tânia W; Albano, Rodolpho M; Marques, Elizabeth A

    2016-01-01

    Acinetobacter pittii has emerged as an important hospital pathogen that is associated with outbreaks and drug resistance. In cystic fibrosis (CF) patients, the detection of Acinetobacter spp. is rare; however, we isolated the A. pittii sequence type ST643 in several Brazilian CF patients treated in the same centre. The current study describes the draft genome of A. pittii ST643. PMID:27653362

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

    OpenAIRE

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

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Al Atrouni

    2016-07-01

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

  7. Proliferation of spacecraft-associated Acinetobacter on alcohol solvents

    Science.gov (United States)

    Mogul, Rakesh; Cepeda, Ivonne; Brasali, Hania; Gornick, Trevor; Jain, Chirag; Kim, Eun Jin; Nguyen, Vinh Bao; Oei, Alex; Rodriguez, Joseph; Walker, Jillian; Savla, Gautam

    The Acinetobacter are the most abundant Gram-negative and non-spore forming bacteria found in the cleanroom facilities for Mars spacecraft. The spacecraft-associated Acinetobacter are extremotolerant towards hydrogen peroxide and have been shown to increase in abundance as a result of the spacecraft assembly process. To better understand the oligotrophic growth in the cleanroom environments, we have measured the growth of several Acinetobacter strains against ethanol and isopropanol, which are cleaning solvents used in the spacecraft assembly process. Our studies show that A. radioresistens 50v1, which was isolated from Mars Odyssey orbiter, optimally proliferates on 300 mM ethanol under minimal conditions at a growth rate that is 2-fold higher than that of the A. radioresistens type strain (strain 43998 (T) ). The impact of transition metals on the growth rates followed the trend of Fe (2+) > Mn (2+) > Zn (2+) , where Zn (2+) was inhibitory. In contrast, no growth on ethanol was observed for the novel species A. phoenicis 2P01AA, which was isolated from the facilities for the Mars Phoenix lander. Alcohol dehydrogenase activities measured in rich and minimal media paralleled these observations with the 50v1 strain possessing higher specific activities than the type strain, and the 2P01AA strain displaying no measurable activity in rich media. Preliminary studies indicate that isopropanol is insufficient as an energy source when in culture. The significance of these results as well as the observed differences between the Odyssey and Phoenix-associated strains will be discussed.

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

    OpenAIRE

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

    2009-01-01

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

  9. Acinetobacter baumannii in Localised Cutaneous Mycobacteriosis in Falcons

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Manju Bala

    2016-07-01

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

  11. Combination of ARDRA and RAPD genotyping techniques in identification of Acinetobacter spp. genomic species

    Institute of Scientific and Technical Information of China (English)

    Yong ZHANG; Yuqing CHEN; Yingchun TANG; Kouxing ZHANG

    2008-01-01

    A total of 10 non-repetitive multi-drug-resist-ant Acinetobacter strains were collected. With reference to A. calcoaceticus (ATCC23055), A. baumannii (ATCC19606), A. lwoffii (ATCC17986), and A. junii (NCTC5866), DNA fingerprint technique, amplified ribo-somal DNA restriction analysis (ARDRA), and random amplified polymorphism DNA (RAPD) were carried out to identify the genomic species of Acinetobacter spp. The distances between them were calculated by the unweighted pair group method with arithmetic (UPGMA). Genotypes ofAcinetobacter spp. were effectively classified and an A. junii together with nine A. baumannii isolates was genomically identified. The combination of ARDRA and RAPD DNA-fingerprint technique shows high com-plementarity, and could be a useful tool in Acinetobacter genomic species identification.

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

    Science.gov (United States)

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

    2014-01-01

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

  13. 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.

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

    Directory of Open Access Journals (Sweden)

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

    2012-08-01

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

  15. Characterization of newly isolated lytic bacteriophages active against Acinetobacter baumannii.

    Science.gov (United States)

    Merabishvili, Maia; Vandenheuvel, Dieter; Kropinski, Andrew M; Mast, Jan; De Vos, Daniel; Verbeken, Gilbert; Noben, Jean-Paul; Lavigne, Rob; Vaneechoutte, Mario; Pirnay, Jean-Paul

    2014-01-01

    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.

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

    OpenAIRE

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

    2014-01-01

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

  17. 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.

  18. 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.

  19. Draft Genome Sequences of Acinetobacter baumannii Isolates from Wounded Military Personnel.

    Science.gov (United States)

    Arivett, Brock A; Ream, Dave C; Fiester, Steven E; Kidane, Destaalem; Actis, Luis A

    2016-01-01

    Acinetobacter baumannii is a Gram-negative bacterium capable of causing hospital-acquired infections that has been grouped with Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species as ESKAPE pathogens because of their extensive drug resistance phenotypes and increasing risk to human health. Twenty-four multidrug-resistant A. baumannii strains isolated from wounded military personnel were sequenced and annotated. PMID:27563036

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

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

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

    2014-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

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

    OpenAIRE

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

    1997-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Naghmeh Moshtaghi

    2009-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Muhammad Sohail

    2016-06-01

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

  6. 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.

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

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

    OpenAIRE

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Yolande Hauck

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

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

    Science.gov (United States)

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

    2016-01-01

    Trimeric autotransporter adhesins (TAAs), cell surface proteins of Gram-negative bacteria, mediate bacterial adhesion to host cells and extracellular matrix proteins. However, AtaA, a TAA in the nonpathogenic Acinetobacter sp. strain Tol 5, shows nonspecific, high adhesiveness to abiotic material surfaces as well as to biotic surfaces. AtaA is a homotrimer of polypeptides comprising 3,630 amino acids and forms long nanofibers; therefore, it is too large and structurally complex to be produced as a recombinant protein. In this study, we isolated AtaA's passenger domain (AtaA PSD), which is translocated to the cell surface through the C-terminal transmembrane domain and exhibits biological functions, using a new method. We introduced a protease recognition site and reaped AtaA nanofibers 225 nm in length from the cell surface through proteolytic cleavage with a specific protease. Biochemical and biophysical analyses of the purified native AtaA PSD revealed that it has a stable structure under alkaline and acidic conditions. Temperatures above 80 °C, which disrupted AtaA's higher-order structure but maintained the full-length AtaA polypeptide, inactivated AtaA's nonspecific adhesiveness, suggesting that the stickiness of AtaA requires its 3D structure. This finding refutes the widespread but vague speculation that large unfolded polypeptides readily stick to various surfaces. PMID:27305955

  12. A selective medium for the isolation of the acinetobacter genus bacteria Um Meio Seletivo para o Isolamento de Bactérias do Gênero Acinetobacter

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    Altair A. Zebral

    1980-12-01

    Full Text Available A selective and differencial medium was developed for the isolation of Acinetobacter genus bacteria. This Acinobacter Agar Medium (p.H + 7.4 contains in grams per litre: thiotone, 10; yeast extract, 3; naC1, 5; saccharose, 10; mannitol, 10; sodium citrate, 0.5; sodium desoxycholate, 0.1; crystal violet, 0.00025; phenol red, 0.04 and agar-agar 15. This medium has the advantage of inhibiting the growth of cocci and Gram-positive bacilli, by the use of sodium citrate and sodium desoxycholate associated with the crystal violet; and of differentiating the Gram-negative bacilli from the Enterobacteriaceae, through the fermentative activity upon the saccharose and/or mannitol, contrasting with the complete inactivity of the Acinetobacter genus bacteria over those substances.Um meio seletivo e diferenciador foi desenvolvido para facilitar o isolamento das bactérias do gênero Acinetobacter. Este meio (Agar Acinetobacter contém em gramas por litro: Tiotone (BBL, 10; extrato de levedura (BBL, 3; NaC1, 5; sacarose, 10; manitol, 10; citrato de sódio, 0,5; desoxicolato de sódio, 0,1; cristal violeta, 0,00025; vermelho de fenol, 0,04 e pH 7,4. Apresenta a vantagem de impedir o crescimento dos cocos e bacilos Gram positivos, pelo emprego do citrato de sódio e do desoxicolato de sódio, associados ao cristal violeta e de diferenciar os bacilos Gram negativos da família Enterobacteriaceae, pela sua atividade fermentativa sobre a sacarose e/ou manitol, em contraste com a completa inatividade das bactérias do gênero Acinetobacter sobre os mesmos substratos.

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

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    Pratap Siddharth

    2010-07-01

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

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

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    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)

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

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    Bin Liu

    2014-07-01

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

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

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

    2016-01-01

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

  18. Biodegradation of methyl parathion by Acinetobacter radioresistens USTB-04

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Biodegradation of methyl parathion (MP), a widely used organophosphorus pesticide, was investigated using a newly isolated bacterium strain Acinetobacter radioresistens USTB-04. MP at an initial concentration of 1200 mg/L could be totally biodegraded by A. radioresistens USTB-04 as the sole carbon source less than 4 d in the presence of phosphate and urea as phosphorus and nitrogen sources, respectively. Biodegradation of MP was also achieved using cell-free extract of A. radioresistens USTB-04. MP at an initial concentration of 130 mg/L was completely biodegraded in 2 h in the presence of cell-free extract with a protein concentration of 148.0mg/L, which was increased with the increase of pH from 5.0 to 8.0. Contrary to published reports, no intermediate or final degradation metabolites of MP could be observed. Thus we suggest that the cleavage of C-C bond on the benzene ring other than P-O bond may be the biodegradation pathway of MP by A. radioresistens USTB-04.

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

    Science.gov (United States)

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

    2016-01-01

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

  20. Stereochemical insignificance discovered in Acinetobacter baumannii quorum sensing.

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    Amanda L Garner

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

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

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    Dahraoui Souhail

    2016-01-01

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

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

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    Abdolaziz Rastegar Lari

    2012-03-01

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

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

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    Saavedra, Sandra Yamile; Cayô, Rodrigo; Gales, Ana Cristina; Leal, Aura Lucia; Saavedra, Carlos Humberto

    2014-01-01

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

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

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    Apoorva

    2014-07-01

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

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

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    Adrián Golic

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

  6. In vitro susceptibility pattern of acinetobacter species to commonly used cephalosporins, quinolones, and aminoglycosides

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    Prashanth K

    2004-01-01

    Full Text Available PURPOSE: Acinetobacter spp. is an emerging important nosocomial pathogen. Clinical isolates of this genus are often resistant to many antibiotics. The in vitro susceptibility of Acinetobacter isolates obtained from patients were tested for currently used antibiotics. In addition, the study aimed at biotyping of Acinetobacter baumannii. METHODS: A total of 66 isolates were phenotypically characterised through a large panel of 25 carbon assimilation tests and susceptibility through disc diffusion method with 10 antimicrobial agents were tested. MICs were determined only for second line broad-spectrum drugs such as cefotaxime, ceftazidime, amikacin, ciprofloxacin, and ofloxacin using NCCLS guidelines. RESULTS: Multiple drug resistance (MDR was only witnessed in A. baumannii and not in other Acinetobacter species. Aminoglycosides such as amikacin, netilmicin were most active against the MDR isolates tested (60% susceptibility. Ceftazidime was more active than cefotaxime. MDR A. baumannii strains were susceptible only to amikacin, netilmicin and ceftadizime. Ciprofloxacin had poor activity irrespective of isolates belonging to different DNA groups tested (58% resistance overall, 79% among A. baumannii. Strains of Biotypes 6 and 19 of A. baumannii showed broader resistance than those of biotype 10 and others. CONCLUSIONS: Strains of A. baumannii from patients in our hospital, were generally more resistant to quinolones, -lactam antibiotics, first and second generation cephalosporins and partially resistant to third generation cephalosporins and aminoglycosides. The strains belonging to other DNA groups of Acinetobacter were comparatively less resistant than A.baumannii, except ciprofloxacin. This study suggests that, a combination therapy, using a third generation cephalosporin and amikacin, would be best choice for treating Acinetobacter infections.

  7. Neglected Fournier's Gangrene Caused by Acinetobacter baumannii: A Rare Case Report

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    Emre, Arif; Sertkaya, Mehmet; Duman, Yakup; Kale, Ilhami Taner

    2016-01-01

    Fournier's gangrene, rare but life threatening disease, is characterized by an acute necrotic infection of the scrotum, penis, or perineum. Fournier's gangrene is a mixed infection caused by both aerobic and anaerobic bacteria. Fournier's gangrene caused by multidrug resistant Acinetobacter baumannii have been reported rarely. The mainstay of treatment is prompt recognition and a combination of antibiotics with radical debridement. We describe a case of a 56-year-old male patient presenting with neglected Fournier's gangrene caused by Acinetobacter baumannii. Many treatment modalities including broad-spectrum antibiotics, aggressive debridement, negative pressure wound therapy, diversion colostomy, and partial-thickness skin grafts were applied to save the patient's life. PMID:27725892

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

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    Nitin Kumar Singh

    2014-12-01

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

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

    Science.gov (United States)

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

    2012-05-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  11. Risk factors for mortality in Acinetobacter calcoaceticus-baumannii bacteraemia

    Institute of Scientific and Technical Information of China (English)

    Asmita A Mehta; V Anil Kumar; Kumari Indira K; Suresh G Nair; Kavitha R Dinesh; Sanjeev K Singh

    2012-01-01

    Objective: To determine the risk factors associated with mortality in Acinetobacter calcoaceticus–baumannii (Acb) complex blood stream infection. Methods: This was an observational study conducted in tertiary care hospital of South India. All patients with blood culture positive for Acb complex from January 2008 to December 2009 were included and a standardized abstraction form was used to abstract data. P value was calculated by Chi square test. Univariate analysis was done by using 2x2 tables and the variables with P value of <0.1 were further subjected to multivariate analysis. Multivariate analysis was done by logistic regression method. Results: After excluding the polymicrobial infections and duplicate isolates from the same patients, 81 cases were included in our study. Out of 81 patients, 20 (24.6%) patients had positive isolate from body secretion other than blood for Acb complex, majority were hospitalized in intensive care unit (74%), had indwelling vascular catheters (68%) and were mechanically ventilated (61%). Multi drug resistant phenotypes were seen in 56 (69.1%) isolates and among them 13 (16%) were resistant to carbapenems. Univariate analysis showed renal disease, diabetes mellitus, use of mechanical ventilation and absence of appropriate antibiotic therapy, leucopenia, thrombocytopenia and raised prothrombin time were related to increased mortality in Acb complex bacteraemia. However, in multivariate analysis independent risk factors for mortality in Acb complex bacteraemia were platelets of less than 1.5 lacks and inappropriate empirical antibiotics. Conclusions: Thrombocytopenia and absence of appropriate antibiotics were risk factors associated with mortality in Acb bacteraemia. Patients with blood culture showing Acb complex bacteraemia with above findings should be attended with aggressive management. Clinician of hospitals with high incidence of Acb complex bacteraemia, should predict the chances of such infection even prior to blood

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

    Science.gov (United States)

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

    2014-01-01

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

  13. Antibiotic modulation of capsular exopolysaccharide and virulence in Acinetobacter baumannii.

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    Edward Geisinger

    2015-02-01

    Full Text Available Acinetobacter baumannii is an opportunistic pathogen of increasing importance due to its propensity for intractable multidrug-resistant infections in hospitals. All clinical isolates examined contain a conserved gene cluster, the K locus, which determines the production of complex polysaccharides, including an exopolysaccharide capsule known to protect against killing by host serum and to increase virulence in animal models of infection. Whether the polysaccharides determined by the K locus contribute to intrinsic defenses against antibiotics is unknown. We demonstrate here that mutants deficient in the exopolysaccharide capsule have lowered intrinsic resistance to peptide antibiotics, while a mutation affecting sugar precursors involved in both capsule and lipopolysaccharide synthesis sensitizes the bacterium to multiple antibiotic classes. We observed that, when grown in the presence of certain antibiotics below their MIC, including the translation inhibitors chloramphenicol and erythromycin, A. baumannii increases production of the K locus exopolysaccharide. Hyperproduction of capsular exopolysaccharide is reversible and non-mutational, and occurs concomitantly with increased resistance to the inducing antibiotic that is independent of the presence of the K locus. Strikingly, antibiotic-enhanced capsular exopolysaccharide production confers increased resistance to killing by host complement and increases virulence in a mouse model of systemic infection. Finally, we show that augmented capsule production upon antibiotic exposure is facilitated by transcriptional increases in K locus gene expression that are dependent on a two-component regulatory system, bfmRS. These studies reveal that the synthesis of capsule, a major pathogenicity determinant, is regulated in response to antibiotic stress. Our data are consistent with a model in which gene expression changes triggered by ineffectual antibiotic treatment cause A. baumannii to transition

  14. Kinetic properties and inhibition of Acinetobacter glutaminase-asparaginase.

    Science.gov (United States)

    Steckel, J; Roberts, J; Philips, F S; Chou, T C

    1983-03-15

    Kinetic parameters, substrate specificity and exclusivity of ligands at binding sites of L-glutaminase-L-asparaginase purified from Acinetobacter glutaminasificans were studied in order to gain knowledge about the dual activities of this enzyme and its inhibition by structural analogs. Both L-glutamine and L-asparagine, which showed similar Km (4 approximately 7 X 10(-5) M) and Vmax (molecular activity 1.0 min-1) values, were competitive with each other for the substrate binding site. The products, L-glutamic acid and L-aspartic acid, showed competitive inhibition with respect to either L-glutamine or L-asparagine as substrates. Multiple inhibition of the glutaminase activity by L-glutamic acid and L-aspartic acid indicated that these ligands are mutually exclusive at the product-releasing site. The initial rates of both of the enzyme's activities were competitively inhibited by the following inhibitors (in rates of both of the enzyme's activities were competitively inhibited by the following inhibitors (in decreasing order of activity): 6-diazo-5-oxo-L-norleucine (DON), L-methionine sulfoximine, azaserine, and Acivicin. DON and azaserine inhibited both the asparaginase and glutaminase activities in a time-dependent and irreversible manner. The kinetic data suggest an ordered mechanism with glutamine or asparagine as the first substrate and glutamic acid or aspartic acid, respectively, as the last product. These results also suggest that a single mechanism and a single set of binding sites are responsible for catalyzing both of the enzyme's activities. The data also showed that succinylated enzyme, which has a 10-fold increase of plasma half-life in animals and humans and, thus, has benefit as a cancer chemotherapeutic agent, retained its catalytic activity and maintained Km and Vmax values similar to the native enzyme.

  15. 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

  16. 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.

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

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    Sivasankari S

    2014-03-01

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

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

    Science.gov (United States)

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

    2009-12-01

    Infections caused by bacteria of genus Acinetobacter pose a significant health care challenge worldwide. Information on molecular epidemiological investigation of outbreaks caused by Acinetobacter species in Kosova is lacking. The present investigation was carried out to enlight molecular epidemiology of Acinetobacter baumannii in the Central Intensive Care Unit (CICU) of a University hospital in Kosova using pulse field gel electrophoresis (PFGE). During March - July 2006, A. baumannii was isolated from 30 patients, of whom 22 were infected and 8 were colonised. Twenty patients had ventilator-associated pneumonia, one patient had meningitis, and two had coinfection with bloodstream infection and surgical site infection. The most common diagnoses upon admission to the ICU were politrauma and cerebral hemorrhage. Bacterial isolates were most frequently recovered from endotracheal aspirate (86.7%). First isolation occurred, on average, on day 8 following admission (range 1-26 days). Genotype analysis of A. baumannii isolates identified nine distinct PFGE patterns, with predominance of PFGE clone E represented by isolates from 9 patients. Eight strains were resistant to carbapenems. The genetic relatedness of Acinetobacter baumannii was high, indicating cross-transmission within the ICU setting. These results emphasize the need for measures to prevent nosocomial transmission of A. baumannii in ICU. PMID:20464330

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

    Science.gov (United States)

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

    2016-09-01

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

  20. Infrequent Air Contamination with Acinetobacter baumannii of Air Surrounding Known Colonized or Infected Patients

    OpenAIRE

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

    2015-01-01

    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.

  1. 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.

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

    Directory of Open Access Journals (Sweden)

    MH Nazem Shirazi

    2010-06-01

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

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

    OpenAIRE

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

    2011-01-01

    Abstract Background Extensive drug resistance of Acinetobacter baumannii is a serious problem in the clinical setting. It is therefore important to find active antibiotic combinations that could be effective in the treatment of infections caused by this problematic 'superbug'. In this study, we analyzed the in vitro activities of three colistin-based combinations and a minocycline-based combination against clinically isolated extensive drug resistant Acinetobacter baumannii (XDR-AB) strains. ...

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

    Science.gov (United States)

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

    2016-01-01

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

  5. Identification of Acinetobacter baumannii by detection of the blaOXA-51-like carbapenemase gene intrinsic to this species.

    Science.gov (United States)

    Turton, Jane F; Woodford, Neil; Glover, Judith; Yarde, Susannah; Kaufmann, Mary E; Pitt, Tyrone L

    2006-08-01

    bla(OXA-51-like) was sought in clinical isolates of Acinetobacter species in a multiplex PCR, which also detects bla(OXA-23-like) and class 1 integrase genes. All isolates that gave a band for bla(OXA-51-like) identified as A. baumannii. This gene was detected in each of 141 isolates of A. baumannii but not in those of 22 other Acinetobacter species.

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

    Science.gov (United States)

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

    2015-05-01

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

  7. 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.

  8. Carbapenem Resistance in Acinetobacter baumannii and Other Acinetobacter spp. Causing Neonatal Sepsis: Focus on NDM-1 and Its Linkage to ISAba125

    Science.gov (United States)

    Chatterjee, Somdatta; Datta, Saswati; Roy, Subhasree; Ramanan, Lavanya; Saha, Anindya; Viswanathan, Rajlakshmi; Som, Tapas; Basu, Sulagna

    2016-01-01

    Carbapenem-resistant determinants and their surrounding genetic structure were studied in Acinetobacter spp. from neonatal sepsis cases collected over 7 years at a tertiary care hospital. Acinetobacter spp. (n = 68) were identified by ARDRA followed by susceptibility tests. Oxacillinases, metallo-β-lactamases (MBLs), extended-spectrum β-lactamases and AmpCs, were detected phenotypically and/or by PCR followed by DNA sequencing. Transconjugants possessing the blaNDM−1(New Delhi metallo-β-lactamase) underwent further analysis for plasmids, integrons and associated genes. Genetic environment of the carbapenemases were studied by PCR mapping and DNA sequencing. Multivariate logistic regression was used to identify risk factors for sepsis caused by NDM-1-harboring organisms. A. baumannii (72%) was the predominant species followed by A. calcoaceticus (10%), A. lwoffii (6%), A. nosocomialis (3%), A. junni (3%), A. variabilis (3%), A. haemolyticus (2%), and 14TU (2%). Fifty six percent of the isolates were meropenem-resistant. Oxacillinases present were OXA-23-like, OXA-58-like and OXA-51-like, predominately in A. baumannii. NDM-1 was the dominant MBL (22%) across different Acinetobacter spp. Isolates harboring NDM-1 also possessed bla(VIM−2, PER−1, VEB−2, CTX−M−15), armA, aac(6′)Ib, aac(6′)Ib-cr genes. blaNDM−1was organized in a composite transposon between two copies of ISAba125 in the isolates irrespective of the species. Further, OXA-23-like gene and OXA-58-like genes were linked with ISAba1 and ISAba3 respectively. Isolates were clonally diverse. Integrons were variable in sequence but not associated with carbapenem resistance. Most commonly found genes in the 5′ and 3′conserved segment were aminoglycoside resistance genes (aadB, aadA2, aac4′), non-enzymatic chloramphenicol resistance gene (cmlA1g) and ADP-ribosylation genes (arr2, arr3). Outborn neonates had a significantly higher incidence of sepsis due to NDM-1 harboring isolates than

  9. Carbapenem resistance in Acinetobacter baumannii and other Acinetobacter spp. causing neonatal sepsis: focus on NDM-1 and its linkage to ISAba125

    Directory of Open Access Journals (Sweden)

    Somdatta Chatterjee

    2016-08-01

    Full Text Available Carbapenem-resistant determinants and their surrounding genetic structure were studied in Acinetobacter spp. from neonatal sepsis cases collected over 7 years at a tertiary care hospital. Acinetobacter spp. (n=68 were identified by ARDRA followed by susceptibility tests. Oxacillinases, metallo-β-lactamases (MBLs, extended-spectrum β-lactamases and AmpCs, were detected phenotypically and/or by PCR followed by sequencing. Transconjugants possessing the blaNDM-1 (New Delhi metallo-β-lactamases underwent further analysis for plasmids, integrons and associated genes. Genetic environment of the carbapenemases were studied by PCR mapping and sequencing. Multivariate logistic regression was used to identify risk factors for sepsis caused by NDM-1-harbouring organisms. A. baumannii (72% was the predominant species followed by A. calcoaceticus (10%, A. lwoffii (6%, 13TU (3%, A. junni (3%, 15TU (3%, A. haemolyticus (2% and 14TU (2%. Fifty six percent of the isolates were meropenem-resistant. Oxacillinases present were OXA-23-like, OXA-58-like and OXA-51-like, predominately in A. baumannii. NDM-1 was the dominant MBL (22% across different Acinetobacter spp. Isolates harbouring NDM-1 also possessed bla(VIM-2, PER-1, VEB-2, CTX-M-15, armA, aac(6’Ib, aac(6’Ib-cr genes. blaNDM-1 was organised in a composite transposon between two copies of ISAba125 in the isolates irrespective of the species. Further, OXA-23-like gene and OXA-58-like genes were linked with ISAba1 and ISAba3 respectively. Isolates were clonally diverse. Integrons were variable in sequence but not associated with carbapenem resistance. Most commonly found genes in the 5’ and 3’conserved segment were aminoglycoside resistance genes (aadB, aadA2, aac4’, non-enzymatic chloramphenicol resistance gene (cmlA1g and ADP-ribosylation genes (arr2, arr3. Outborn neonates had a significantly higher incidence of sepsis due to NDM-1 harbouring isolates than their inborn counterparts. This study

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

    OpenAIRE

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

    2012-01-01

    One of the most serious diseases in potato cultivars is caused by the pathogen Phytophthora infestans, which affects leaves, stems and tubers. Metalaxyl is a fungicide that protects potato plants from Phytophthora infestans. In Mexico, farmers apply metalaxyl 35 times during the cycle of potato production and the last application is typically 15 days before harvest. There are no records related to the presence of metalaxyl in potato tubers in Mexico. In the present study, we evaluated the eff...

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    OpenAIRE

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

    2013-01-01

    The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii) is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrob...

  15. Metabolism of spacecraft cleaning reagents by Mars Odyssey and Phoenix-associated Acinetobacter

    Science.gov (United States)

    Mogul, Rakesh; Barding, Gregory; Baki, Ryan; Perkins, Nicole; Lee, Sooji; Lalla, Sid; Campos, Alexa; Sripong, Kimberly; Madrid, Steve

    2016-07-01

    The metabolomic and proteomic properties that promote microbial survival in spacecraft assembly facilities are important aspects to planetary protection and astrobiology. In this presentation, we will provide molecular and biological evidence that the spacecraft-associated Acinetobacter metabolize/degrade spacecraft cleaning reagents such as ethanol, 2-propanol, and Kleenol-30. Gas chromatography-mass spectrometry (GC-MS) studies on A. radioresistens 50v1 (Mars Odyssey) show that the metabolome is dependent upon growth conditions and that ^{13}C-labeled ethanol is incorporated into metabolites such as TCA/glyoxylate cycle intermediates, amino acids, monosaccharides, and disaccharides (e.g., trehalose). In fact, plate count assays show that ethanol is a sole carbon source under minimal conditions for several Mars Phoenix and Odyssey-associated Acinetobacter strains, which may explain why the Acinetobacter are among the most abundant genera found in spacecraft assembly facilities. Biochemical analyses support the enzymatic oxidation of ethanol and 2-propanol by a membrane-bound and NAD+/PQQ-dependent alcohol dehydrogenase, with current kinetic data providing similar apparent K _{M} and maximum growth rate values of ˜5 and 8 mM ethanol, respectively. Preliminary GC-MS analysis also suggests that Kleenol-30 is degraded by A. radioresistens 50v1 when grown in ethanol mixtures. Under minimal conditions, A. radioresistens 50v1 (˜10 ^{8} cfu/mL) also displays a remarkable oxidative extremotolerance (˜2-log reduction in 10 mM hydrogen peroxide), which suggests crucial roles for metabolites associated with oxidative stress (e.g., trehalose) and the observed appreciable catalase specific activities. In conclusion, these results provide key insights into the survival strategies of spacecraft-associated Acinetobacter and emphasize the importance of characterizing the carbon metabolism of forward contaminants.

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

    OpenAIRE

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

    2011-01-01

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

  17. Prevalence of antibiotic resistance among Acinetobacter baumannii isolates from Aleppo, Syria.

    Science.gov (United States)

    Hamzeh, Abdul Rezzak; Al Najjar, Mona; Mahfoud, Maysa

    2012-10-01

    This study describes and analyzes Acinetobacter baumannii antibiotic susceptibly profile in Aleppo, Syria, thus providing vital information for guiding treatment of A baumannii infections. Two hundred sixty nonrepetitive A baumannii isolates were studied over 3.5 years. Resistance rates are at the higher end of globally reported levels. Newer cephalosporins and β-lactamase-resistant agents are becoming practically ineffective. Better activity is limited to carbapenems and colistin, which elicited the highest susceptibility levels.

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

    OpenAIRE

    Zahra Kassamali; Rupali Jain; Danziger, Larry H.

    2015-01-01

    Objective: To review recent clinical pharmacokinetic and pharmacodynamic data to optimize dosing regimens for polymyxin B and colistin for treatment of infections due to A. baumannii. Methods: A literature search was performed using the search terms Acinetobacter, polymyxin, colistin, polymyxin B on MEDLINE. Additional references were identified from the resulting citations. Results: Increasing the dose of polymyxin B or colistin and using either in combination with other antibiotic age...

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

    OpenAIRE

    Goel, Vikas Kumar; Kapil, Arti

    2001-01-01

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

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

    OpenAIRE

    Keramettin Yanik

    2015-01-01

    Aim: Due to existing multi drug resistance and subsequently acquired resistance Acinetobacter genus bacteria continuously actual. Other characteristics are increasing treatment costs, patient hospitalization period, mortality and morbidity. Risk factors like extended hospitalization period, background immune system disorders are increasing isolation frequency of this bacteria from patients. Extended spectrum antibiotic usage is known to be a major risk factor. Aim of our study is to investiga...

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

    OpenAIRE

    Rodr??guez Falc??n, Manuel

    2010-01-01

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

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

    OpenAIRE

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

    2013-01-01

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

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

    OpenAIRE

    Rodríguez Falcón, Manuel

    2010-01-01

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

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

    OpenAIRE

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

    2011-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

  7. Differential Protection from Tobramycin by Extracellular Polymeric Substances from Acinetobacter baumannii and Staphylococcus aureus Biofilms

    OpenAIRE

    Davenport, Emily K.; Douglas R. Call; Beyenal, Haluk

    2014-01-01

    We investigated biofilms of two pathogens, Acinetobacter baumannii and Staphylococcus aureus, to characterize mechanisms by which the extracellular polymeric substance (EPS) found in biofilms can protect bacteria against tobramycin exposure. To do so, it is critical to study EPS-antibiotic interactions in a homogeneous environment without mass transfer limitations. Consequently, we developed a method to grow biofilms, harvest EPS, and then augment planktonic cultures with isolated EPS and tob...

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

    OpenAIRE

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

    2015-01-01

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

  9. 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.

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

    OpenAIRE

    Shabtai, Y; Gutnick, D L

    1985-01-01

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

  11. Genomic and functional analysis of the type VI secretion system in Acinetobacter.

    Directory of Open Access Journals (Sweden)

    Brent S Weber

    Full Text Available The genus Acinetobacter is comprised of a diverse group of species, several of which have raised interest due to potential applications in bioremediation and agricultural purposes. In this work, we show that many species within the genus Acinetobacter possess the genetic requirements to assemble a functional type VI secretion system (T6SS. This secretion system is widespread among Gram negative bacteria, and can be used for toxicity against other bacteria and eukaryotic cells. The most studied species within this genus is A. baumannii, an emerging nosocomial pathogen that has become a significant threat to healthcare systems worldwide. The ability of A. baumannii to develop multidrug resistance has severely reduced treatment options, and strains resistant to most clinically useful antibiotics are frequently being isolated. Despite the widespread dissemination of A. baumannii, little is known about the virulence factors this bacterium utilizes to cause infection. We determined that the T6SS is conserved and syntenic among A. baumannii strains, although expression and secretion of the hallmark protein Hcp varies between strains, and is dependent on TssM, a known structural protein required for T6SS function. Unlike other bacteria, A. baumannii ATCC 17978 does not appear to use its T6SS to kill Escherichia coli or other Acinetobacter species. Deletion of tssM does not affect virulence in several infection models, including mice, and did not alter biofilm formation. These results suggest that the T6SS fulfils an important but as-yet-unidentified role in the various lifestyles of the Acinetobacter spp.

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

    Directory of Open Access Journals (Sweden)

    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.  

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

    Directory of Open Access Journals (Sweden)

    Lul Raka

    2009-12-01

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

  14. Signature motifs identify an Acinetobacter Cif virulence factor with epoxide hydrolase activity.

    Science.gov (United States)

    Bahl, Christopher D; Hvorecny, Kelli L; Bridges, Andrew A; Ballok, Alicia E; Bomberger, Jennifer M; Cady, Kyle C; O'Toole, George A; Madden, Dean R

    2014-03-14

    Endocytic recycling of the cystic fibrosis transmembrane conductance regulator (CFTR) is blocked by the CFTR inhibitory factor (Cif). Originally discovered in Pseudomonas aeruginosa, Cif is a secreted epoxide hydrolase that is transcriptionally regulated by CifR, an epoxide-sensitive repressor. In this report, we investigate a homologous protein found in strains of the emerging nosocomial pathogens Acinetobacter nosocomialis and Acinetobacter baumannii ("aCif"). Like Cif, aCif is an epoxide hydrolase that carries an N-terminal secretion signal and can be purified from culture supernatants. When applied directly to polarized airway epithelial cells, mature aCif triggers a reduction in CFTR abundance at the apical membrane. Biochemical and crystallographic studies reveal a dimeric assembly with a stereochemically conserved active site, confirming our motif-based identification of candidate Cif-like pathogenic EH sequences. Furthermore, cif expression is transcriptionally repressed by a CifR homolog ("aCifR") and is induced in the presence of epoxides. Overall, this Acinetobacter protein recapitulates the essential attributes of the Pseudomonas Cif system and thus may facilitate airway colonization in nosocomial lung infections. PMID:24474692

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

    Directory of Open Access Journals (Sweden)

    Laure Diancourt

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

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    OpenAIRE

    Carlos Méndez; Eduardo Uribe

    2012-01-01

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

  19. Study of Incidence, Risk Factors and Antibiotic Sensitivity Pattern of Acinetobacter baumannii in a Tertiary Care Hospital

    Directory of Open Access Journals (Sweden)

    Vijaya S Rajmane

    2015-01-01

    Full Text Available Background: Recently, Acinetobacter species has emerged as an important pathogen and the prevalence of infection has increased since last two decades worldwide. Objective: To see the impact of Acinetobacter infection in our hospital and antibiotic sensitivity and resistance pattern. Material and Methods: The study was carried out on clinical samples submitted to the Microbiology laboratory in Krishna institute of Medical Sciences and Research, Karad, over a period of one year (July 2012 to June 2013.Various risk factors like length of hospital stay, ICU admission, any interventions done were noted. Identification and antibiotic susceptibility of the isolates was performed using standard protocol. Results: Out of a total 2728 samples, 86 (3.15% were found to be due to Acinetobacter baumannii. Of the 86 isolates the organism was predominantly isolated from pus samples 48 (55.81% followed by sputum 17 (19.76%, urine 6 (6.97% and blood 4 (4.65%. Out of 86 Acinetobacter isolates, 76 (88.37% showed resistance to Cephalexin, 74 (86.04% each to Cefotaxime and Ceftazidime. The isolates also showed high level of resistance to Ciprofloxacin (82.55%, Ampicillin (77.90% and Gentamicin (74.41%. The isolates from urine samples showed 100% sensitivity to Nitrofurantoin. Imipenem and Meropenem were highly active against the isolate with least resistance of 12.79% each. Conclusion: The present study highlights Acinetobacter species as an important pathogen because of multidrug resistant strains jerking in the hospital environment.

  20. Genome Sequences of Four Acinetobacter baumannii-A. calcoaceticus Complex Isolates from Combat-Related Infections Sustained in the Middle East

    Science.gov (United States)

    Ketter, Patrick; Guentzel, M. Neal; Chambers, James P.; Jorgensen, James; Murray, Clinton K.; Cap, Andrew P.; Yu, Jieh-Juen; Eppinger, Mark

    2014-01-01

    Acinetobacter baumannii is among the most prevalent bacterial causes of combat-related infections on the battlefield. Antibiotic resistance and a poor understanding of the protective host immune responses make treatment difficult. Here, we report the genome sequences of four clinical Acinetobacter baumannii-A. calcoaceticus complex isolates exhibiting significant differences in virulence in a mouse sepsis model. PMID:24503987

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

    Directory of Open Access Journals (Sweden)

    P. S. Shareek

    2012-01-01

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

  2. Multidrug resistant Acinetobacter baumannii--the role of AdeABC (RND family efflux pump in resistance to antibiotics.

    Directory of Open Access Journals (Sweden)

    Marcin Zórawski

    2008-12-01

    Full Text Available Acinetobacter baumannii is an opportunistic pathogen which play the more and more greater role in the pathogenicity of the human. It is often attached with the hospital environment, in which is able easily to survive for many days even in adverse conditions. Acinetobacter baumannii is the species responsible for a serious nosocomial infections, especially in the intensive care units. Option of surviving in natural niches, and in the hospital environment could also be associated with the efflux pump mechanisms. Mechanisms of efflux universally appear in all cells (eukaryotic and prokaryotic and play the physiological important role. In prokaryote, the main functions are evasion of such naturally produced molecules, removal of metabolic products and toxins. These pumps could also be involved in an early stage of infection, such as adhesion to host cells and the colonization. Importantly, they remove commonly used antibiotics from the cell in therapy of infections caused by these bacteria. Efflux pumps exemplify a unique phenomenon in drug resistance: a single mechanism causing resistance against several different classes of antibiotics. In Acinetobacter baumannii, the AdeABC efflux pump, a member of the resistance-nodulation-cell division family (RND, has been well characterized. Aminoglicosides, tetracyclines, erythromycin, chloramphenicol, trimethoprim, fluoroquinolones, some beta-lactams, and also recently tigecycline, were found to be substrates for this pump. Drugs, as substrates for the AdeABC pump, can increase the expression of the AdeABC genes, leading to multidrug resistance (MDR. From this reason, treatment failure and death caused by Acinetobacter baumannii infections or underlying diseases are common. Because the AdeABC pump is widespread in Acinetobacter baumannii, similarly to other pumps in Gram-negative and Gram-positive bacteria, exists a need of searching a new therapeutic solutions. Specific efflux inhibitors of pumps (EPIs

  3. 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. PMID:25243569

  4. 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.

  5. Effects of N-pyrrole substitution on the anti-biofilm activities of oroidin derivatives against Acinetobacter baumannii.

    Science.gov (United States)

    Richards, Justin J; Reed, Catherine S; Melander, Christian

    2008-08-01

    Bacteria of the genus Acinetobacter spp. are rapidly emerging as problematic pathogens in healthcare settings. This is exacerbated by the bacteria's ability to form robust biofilms. Marine natural products incorporating a 2-aminoimidazole (2-AI) motif, namely from the oroidin class of marine alkaloids, have served as a unique scaffold for developing molecules that have the ability to inhibit and disperse bacterial biofilms. Herein we present the anti-biofilm activity of a small library of second generation oroidin analogues against the bacterium Acinetobacter baumannii. PMID:18625555

  6. 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

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

  7. Main: SP8BFIBSP8BIB [PLACE

    Lifescience Database Archive (English)

    Full Text Available SP8BFIBSP8BIB S000184 16-Feb-2001 (last modified) seki One of SPBF binding site (SP...; SP8BF recognizes both SP8a and SP8b sequences; See also SP8BFIBSP8AIB (S000183); SP8BF activity is also fo

  8. Main: SP8BFIBSP8AIB [PLACE

    Lifescience Database Archive (English)

    Full Text Available SP8BFIBSP8AIB S000183 16-Feb-2001 (last modified) seki One of SPBF binding site (SP...o (I.b.); SP8BF recognizes both SP8a and SP8b sequences; See also SP8BFIBSP8BIB (S000184); SP8BF activity is

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

    OpenAIRE

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

    2014-01-01

    Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was r...

  10. 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...

  11. Eksternal ventriküler drenaj sistemiyle ilişkili Acinetobacter baumanii menenjiti

    OpenAIRE

    Aktaş, Osman; Recep KEŞLİ; Yazgi, Halil

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chaudhari Bhushan, L.

    2009-01-01

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

  13. Draft genome sequence of Acinetobacter baumannii strain NCTC 13423, a multidrug-resistant clinical isolate.

    Science.gov (United States)

    Michiels, Joran E; Van den Bergh, Bram; Fauvart, Maarten; Michiels, Jan

    2016-01-01

    Acinetobacter baumannii is a pathogen that is becoming increasingly important and causes serious hospital-acquired infections. We sequenced the genome of A. baumannii NCTC 13423, a multidrug-resistant strain belonging to the international clone II group, isolated from a human infection in the United Kingdom in 2003. The 3,937,944 bp draft genome has a GC-content of 39.0 % and a total of 3672 predicted protein-coding sequences. The availability of genome sequences of multidrug-resistant A. baumannii isolates will fuel comparative genomic studies to help understand the worrying spread of multidrug resistance in this pathogen. PMID:27594976

  14. The effect of terminal cleaning on environmental contamination rates of multidrug-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Strassle, Paula; Thom, Kerri A; Johnson, J Kristie; Johnsonm, J Kristie; Leekha, Surbhi; Lissauer, Matthew; Zhu, Jingkun; Harris, Anthony D

    2012-12-01

    We evaluated the prevalence of multidrug-resistant Acinetobacter baumannii environmental contamination before and after discharge cleaning in rooms of infected/colonized patients. 46.9% of rooms and 15.3% of sites were found contaminated precleaning, and 25% of rooms and 5.5% of sites were found contaminated postcleaning. Cleaning significantly decreased environmental contamination of A baumannii; however, persistent contamination represents a significant risk factor for transmission. Further studies on this and more effective cleaning methods are needed.

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

    Institute of Scientific and Technical Information of China (English)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Yassine Nait Chabane

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

    Tiwari, Monalisa; Roy, Ranita; Tiwari, Vishvanath

    2016-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Saghar Hendiani

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Zakuan Zainy Deris; Mohd Nazri Shafei; Azian Harun

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    Siran Keske

    2014-09-01

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

  3. 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.

  4. EMULSAN ANALYSIS PRODUCED BY LOCALLY ISOLATED BACTERIA AND ACINETOBACTER CALCOACETICUS RAG-1

    Directory of Open Access Journals (Sweden)

    P. Chamanrokh, M. Mazaheri Assadi, A. Noohi, S. Yahyai

    2008-04-01

    Full Text Available Growth of previously isolated bacteria from Iranian oil reservoirs on different carbon and energy sources and under varying conditions have been used to produce a class of extracellular microbial protein-associated lipopolysaccharides named emulsan.Several Bacteria were previously isolated from Iranian oil reservoirs and designated as; Ilam-1 and Paydar-4. In present study, the isolated strains were compared with standard sample of Acinetobacter calcoaceticus RAG-1 from Persian Type Culture Collection (PTCC 1641, IROST. Among the isolated strains, two strains were found to produce an extracellular, emulsifying agent when grown in Mineral Salt Medium containing soya oil, ethanol or local crude oil. The isolated bacteria were cultured and further analysed using protein estimation, reducing sugar analysis, hemolytic activity, surface tension and emulsification activity tests. The crude emulsifier of RAG-1, PAYDAR-4 and ILAM-1 were concentrated from the cell-free culture fluid by ammonium sulfate precipitation to yield 1.89g, 1.78g and 1.69g of bioemulsan respectively. Emulsifying activity was observed over the entire production process. These investigations showed that emulsan produced by isolated Iranian crude oil reservoir were comparable with Acinetobacter calcoaceticus RAG-1 which is made of carbohydrate backbone as its hydrophilic part (N-acetyl-D-galactoseamine, N-acetylgalactoseamine uronic acid, diamino-6-deoxy-D-glucose and fatty acid chain as its hydrophobic portion.

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

    Science.gov (United States)

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

    2016-02-01

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

  6. Genomic fingerprinting Acinetobacter baumannii: amplification of multiple inter-repetitive extragenic palindromic sequences.

    Science.gov (United States)

    Sheehan, C; Lynch, M; Cullen, C; Cryan, B; Greer, P; Fanning, S

    1995-09-01

    Acinetobacter species are important nosocomial pathogens. A rapid and sensitive identification system, capable of providing strain identity at the genetic level, is required to identify outbreak strains and facilitate the early implementation of infection control procedures. Repetitive extragenic palindromic (REP) elements, have been identified in numerous bacteria and these genomic sequences provide useful targets for DNA amplification. A method for amplifying inter-REP DNA sequences, REP-multiple arbitrary amplicon profiling (REP-MAAP), is described and applied to 29 Acinetobacter baumannii from clinical samples. Amplified polymorphic DNA patterns were demonstrated for all isolates and those displaying identical REP-MAAP patterns were considered identical at the genetic level. In the spring of 1993, 10 intensive care unit patients had endotracheal colonization with A. baumannii (five with REP-MAAP I and five with REP-MAAP II patterns). These findings suggested nosocomial transmission of organisms which was terminated by standard infection control measures. No further A. baumannii were detected until the winter of 1993 when isolates of different REP-MAAP groups emerged, suggesting that factors other than nosocomial transmission were implicated.

  7. The acute-phase response and serum amyloid a inhibit the inflammatory response to Acinetobacter baumannii pneumonia

    NARCIS (Netherlands)

    R. Renckens; J.J.T.H. Roelofs; S. Knapp; A.F. de Vos; S. Florquin; T. van der Poll

    2006-01-01

    Background. Acinetobacter baumannii is an emerging pathogen in nosocomial pneumonia. Trauma and post-surgical 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 influe

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

    Science.gov (United States)

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

    2015-01-01

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

  9. 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...

  10. 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...

  11. 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.

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

    Science.gov (United States)

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

    2011-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Weimei Ou

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

  14. Genome shuffling improves production of the low-temperature alkalophilic lipase by Acinetobacter johnsonii.

    Science.gov (United States)

    Wang, HaiKuan; Zhang, Jie; Wang, XiaoJie; Qi, Wei; Dai, YuJie

    2012-01-01

    The production of a low-temperature alkalophilic lipase from Acinetobacter johnsonii was improved using genome shuffling. The starting populations, obtained by UV irradiation and diethyl sulfate mutagenesis, were subjected to recursive protoplast fusion. The optimal conditions for protoplast formation and regeneration were 0.15 mg lysozyme/ml for 45 min at 37°C. The protoplasts were inactivated under UV for 20 min or heated at 60°C for 60 min and a fusant probability of ~98% was observed. The positive colonies were created by fusing the inactivated protoplasts. After two rounds of genome shuffling, one strain, F22, with a lipase activity of 7 U/ml was obtained. PMID:21972140

  15. New Delhi metallo-beta-lactamase-1-producing Acinetobacter spp. infection: report of a survivor

    Directory of Open Access Journals (Sweden)

    Fabiana Schuelter-Trevisol

    2016-02-01

    Full Text Available Abstract: New Delhi metallo-beta-lactamase-1 (NDM-1 is a bacterial enzyme that renders the bacteria resistant to a variety of beta-lactam antibiotics. A 20-year-old man was hospitalized several times for surgical treatment and complications caused by a right-sided vestibular schwannoma. Although the patient acquired several multidrug-resistant infections, this study focuses on the NDM-1-producing Acinetobacter spp. infection. As it was resistant to all antimicrobials tested, the medical team developed a 20-day regimen of 750mg/day metronidazole, 2,000,000IU/day polymyxin B, and 100mg/day tigecycline. The treatment was effective, and the patient recovered and was discharged from the hospital.

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

    Science.gov (United States)

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

    2013-01-01

    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. PMID:23295477

  17. Enhancing the hexavalent chromium bioremediation potential of Acinetobacter junii VITSUKMW2 using statistical design experiments.

    Science.gov (United States)

    Pulimi, Mrudula; Jamwal, Subika; Samuel, Jastin; Chandrasekaran, Natarajan; Mukherjee, Amitava

    2012-12-01

    The Cr(VI) removal capability of Acinetobacter junii VITSUKMW2 isolated from the Sukinda chromite mine site was evaluated and enhanced using statistical design techniques. The removal capacity was evaluated at different pH values (5-11) and temperatures (30-40 degrees C) and with various carbon and nitrogen sources. Plackett- Burman design was used to select the operational parameters for bioremediation of Cr(VI). Three parameters (molasses, yeast extract, and Cr(VI) concentration) were chosen for further optimization using central composite design. The optimal combination of parameters was found to be 14.85 g/l molasses, 4.72 g/l yeast extract, and 54 mg/l initial Cr(VI), with 99.95% removal of Cr(VI) in 12 h. A. junii VITSUKMW2 was shown to have significant potential for removal of Cr(VI).

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

    Science.gov (United States)

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

    2014-08-01

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

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

    Directory of Open Access Journals (Sweden)

    F Simsek

    2012-01-01

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

  20. Inactivation of Acinetobacter baumannii Biofilms on Polystyrene, Stainless Steel, and Urinary Catheters by Octenidine Dihydrochloride.

    Science.gov (United States)

    Narayanan, Amoolya; Nair, Meera S; Karumathil, Deepti P; Baskaran, Sangeetha A; Venkitanarayanan, Kumar; Amalaradjou, Mary Anne Roshni

    2016-01-01

    Acinetobacter baumannii is a major nosocomial pathogen causing human infections with significant mortality rates. In most cases, infections are acquired through exposure to A. baumannii biofilms that persist on contaminated hospital equipment and surfaces. Thus, it is imperative to develop effective measures for controlling A. baumannii biofilms in nosocomial settings. This study investigated the efficacy of octenidine dihydrochloride (OH), a new generation disinfectant for reducing A. baumannii biofilms on polystyrene, stainless steel and catheters. OH at 0.3% (5 mM), 0.6% (10 mM), and 0.9% (15 mM) was effective in significantly inactivating A. baumannii biofilms on all tested surfaces (P antibiofilm assay. These data underscore the efficacy of OH in inactivating A. baumannii biofilms, thereby suggesting its potential use as a disinfectant or a catheter lock solution to control A. baumannii infections. PMID:27375572

  1. The role of ISAba1 in expression of OXA carbapenemase genes in Acinetobacter baumannii.

    Science.gov (United States)

    Turton, Jane F; Ward, M Elaina; Woodford, Neil; Kaufmann, Mary E; Pike, Rachel; Livermore, David M; Pitt, Tyrone L

    2006-05-01

    ISAba1 was found in all widespread clones of Acinetobacter baumannii in the United Kingdom. All isolates studied had a blaOXA-51-like carbapenemase gene; some also had blaOXA-23-like and/or blaOXA-58-like. Among isolates with blaOXA-51-like as sole carbapenemase gene, only those with ISAba1 adjacent to blaOXA-51-like were carbapenem resistant. Minor differences in blaOXA-51-like sequence were observed in resistant and susceptible isolates. Isolates with blaOXA-23-like in addition were consistently resistant to carbapenems; in all of these ISAba1 lay upstream of blaOXA-23-like, but was not associated with blaOXA-51-like. These results suggest that ISAba1 is providing the promoter for blaOXA-51-like and, probably, for blaOXA-23-like.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    OpenAIRE

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

    2002-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Wan G

    2016-08-01

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

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

    International Nuclear Information System (INIS)

    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)

  8. 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. PMID:27644087

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

    Directory of Open Access Journals (Sweden)

    Maria Cristina Bronharo Tognim

    1999-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Carlos Méndez

    2012-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Pablo Vitoriano Cirino

    2008-08-01

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

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

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-03-01

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

  14. 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...

  15. Differential roles of antimicrobials in the acquisition of drug resistance through activation of the SOS response in Acinetobacter baumannii.

    Science.gov (United States)

    Jara, Luis M; Cortés, Pilar; Bou, Germán; Barbé, Jordi; Aranda, Jesús

    2015-07-01

    The effect of antimicrobials on SOS-mediated mutagenesis induction depends on the bacterial species and the antimicrobial group. In this work, we studied the effect of different families of antimicrobial agents used in clinical therapy against Acinetobacter baumannii in the induction of mutagenesis in this multiresistant Gram-negative pathogen. The data showed that ciprofloxacin and tetracycline induce SOS-mediated mutagenesis, whereas colistin and meropenem, which are extensively used in clinical therapy, do not.

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

    OpenAIRE

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

    2011-01-01

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

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

    OpenAIRE

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

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

    OpenAIRE

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

    2009-01-01

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

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

    OpenAIRE

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

    2016-01-01

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

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

    OpenAIRE

    Abbas Bahador; Hossein Saghii; Ramezal Ataee; Davoud Esmaeili

    2015-01-01

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

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

    OpenAIRE

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

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

    OpenAIRE

    Kucan, John O.; Heggers, John P.

    2005-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mirjana Lulic-Botica

    2011-01-01

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

  6. Inhibition of Acinetobacter baumannii, Staphylococcus aureus and Pseudomonas aeruginosa biofilm formation with a class of TAGE-triazole conjugates.

    Science.gov (United States)

    Huigens, Robert W; Rogers, Steven A; Steinhauer, Andrew T; Melander, Christian

    2009-02-21

    A chemically diverse library of TAGE-triazole conjugates was synthesized utilizing click chemistry on the TAGE scaffold. This library of small molecules was screened for anti-biofilm activity and found to possess the ability of inhibiting biofilm formation against Acinetobacter baumannii, Staphylococcus aureus and Pseudomonas aeruginosa. One such compound in this library demonstrated the most potent inhibitory effect against Staphylococcus aureus biofilm formation that has been displayed by any 2-aminoimidazole derivative. PMID:19194596

  7. 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

  8. SP-100 Test Site

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Gao F

    2015-03-01

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

  10. Antimicrobial susceptibility profiling and genomic diversity of Acinetobacter baumannii isolates: A study in western Iran.

    Directory of Open Access Journals (Sweden)

    Parviz Mohajeri

    2013-09-01

    Full Text Available Acinetobacter baumannii is an aerobic non-motile Gram-negative bacterial pathogen that is resistant to most antibiotics. Carbapenems are the most common antibiotics for the treatment of infections caused by this pathogen. Mechanisms of antibiotic-resistance in A. baumannii are mainly mediated by efflux pumps-lactamases. The aim of this study was to determine antibiotic susceptibility, the possibility of existence of OXAs genes and fingerprinting by Pulsed-Field Gel Electrophoresis (PFGE among clinical isolates of Acinetobacter collected from Kermanshah hospitals.One hundred and four isolates were collected from patients attending Imam Reza, Taleghani and Imam Khomeini hospitals of Kermanshah (Iran. Isolates were identified by biochemical tests and API 20NE kit. The susceptibility to different antibiotics was assessed with Kirby-Bauer disk diffusion method. PCR was performed for detection of bla OXA-23, bla OXA-24, bla OXA-51 and bla OXA-58 beta-lactamase genes. Clonal relatedness was estimated by PFGE (with the restriction enzyme Apa I and DNA patterns were analyzed by Gel compare II 6.5 software.All isolates showed high-level of resistance to imipenem, meropenem as well as to other antimicrobial agents, while no resistance to polymyxin B, colistin, tigecylcine and minocycline was observed. The bla OXA-23like and bla OXA-24 like were found among 77.9% and 19.2% of the isolates, respectively. All isolates were positive for bla OXA-51, but none produced any amplicon for bla OXA-58. PFGE genotype analysis suggested the existence of eight clones among the 104 strains [A (n = 35, B (n = 29, C (n = 19, D (n = 10, E (n = 4, F (n = 3, G (n = 3, H (n = 1]. Clone A was the dominant clone in hospital settings particularly infection wards so that the isolates in this group, compared to the other clones, showed higher levels of resistance to antibiotics.The bla OXA-51-like and bla OXA-23like were the predominant mechanisms of resistance to imipenem in A

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

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    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

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

    Science.gov (United States)

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

    2009-01-01

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

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

    Science.gov (United States)

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

    2009-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Bora Shin

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

  15. Multidrug Resistance of Acinetobacter Baumannii in Ladoke Akintola University Teaching Hospital, Osogbo, Nigeria

    Science.gov (United States)

    Odewale, G.; Adefioye, O. J.; Ojo, J.; Adewumi, F. A.; Olowe, O. A.

    2016-01-01

    Acinetobacter baumannii is a ubiquitous pathogen that has emerged as a major cause of healthcare-associated infections at Ladoke Akintola University Teaching Hospital. Isolates were assayed according to standard protocol. The isolates were subjected to molecular techniques to detect blaOXA, blaTEM, blaCTX-M, and blaSHV genes in strains of the A. baumannii isolates. The prevalence of A. baumannii was 8.5% and was most prevalent among patients in the age group 51–60 (36%); the male patients (63.6%) were more infected than their female counterparts. Patients (72.7%) in the intensive care unit (ICU) were most infected with this organism. The isolates showed 100% resistance to both amikacin and ciprofloxacin and 90.9% to both ceftriaxone and ceftazidime, while resistance to the other antibiotics used in this study were: piperacillin (81.8%), imipenem (72.7%), gentamycin (72.2%), and meropenem (63.6%). None of the isolates was, however, resistant to colistin. PCR results showed that blaOXA, blaTEM, and blaCTX-M genes were positive in some isolates, while blaSHV was not detected in any of the isolates. This study has revealed that the strains of A. baumannii isolated are multiple drug resistant. Regular monitoring, judicious prescription, and early detection of resistance to these antibiotics are, therefore, necessary to check further dissemination of the organism. PMID:27766173

  16. 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

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

    Directory of Open Access Journals (Sweden)

    Hang eYang

    2015-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Yoko Miyasaki

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

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

    Science.gov (United States)

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

    2013-01-01

    The number of fully active antibiotic options that treat nosocomial infections due to multidrug-resistant Acinetobacter baumannii (A. baumannii) is extremely limited. Magnolia officinalis, Mahonia bealei, Rabdosia rubescens, Rosa rugosa, Rubus chingii, Scutellaria baicalensis, and Terminalia chebula plant extracts were previously shown to have growth inhibitory activity against a multidrug-resistant clinical strain of A. baumannii. In this study, the compounds responsible for their antimicrobial activity were identified by fractionating each plant extract using high performance liquid chromatography, and determining the antimicrobial activity of each fraction against A. baumannii. The chemical structures of the fractions inhibiting >40% of the bacterial growth were elucidated by liquid chromatography/mass spectrometry analysis and nuclear magnetic resonance spectroscopy. The six most active compounds were identified as: ellagic acid in Rosa rugosa; norwogonin in Scutellaria baicalensis; and chebulagic acid, chebulinic acid, corilagin, and terchebulin in Terminalia chebula. The most potent compound was identified as norwogonin with a minimum inhibitory concentration of 128 µg/mL, and minimum bactericidal concentration of 256 µg/mL against clinically relevant strains of A. baumannii. Combination studies of norwogonin with ten anti-Gram negative bacterial agents demonstrated that norwogonin did not enhance the antimicrobial activity of the synthetic antibiotics chosen for this study. In conclusion, of all identified antimicrobial compounds, norwogonin was the most potent against multidrug-resistant A. baumannii strains. Further studies are warranted to ascertain the prophylactic and therapeutic potential of norwogonin for infections due to multidrug-resistant A. baumannii. PMID:23630600

  20. Inactivation of Acinetobacter baumannii Biofilms on Polystyrene, Stainless Steel, and Urinary Catheters by Octenidine Dihydrochloride

    Science.gov (United States)

    Narayanan, Amoolya; Nair, Meera S.; Karumathil, Deepti P.; Baskaran, Sangeetha A.; Venkitanarayanan, Kumar; Amalaradjou, Mary Anne Roshni

    2016-01-01

    Acinetobacter baumannii is a major nosocomial pathogen causing human infections with significant mortality rates. In most cases, infections are acquired through exposure to A. baumannii biofilms that persist on contaminated hospital equipment and surfaces. Thus, it is imperative to develop effective measures for controlling A. baumannii biofilms in nosocomial settings. This study investigated the efficacy of octenidine dihydrochloride (OH), a new generation disinfectant for reducing A. baumannii biofilms on polystyrene, stainless steel and catheters. OH at 0.3% (5 mM), 0.6% (10 mM), and 0.9% (15 mM) was effective in significantly inactivating A. baumannii biofilms on all tested surfaces (P < 0.05). Furthermore, OH was equally effective in inactivating biofilms of multidrug resistant and drug susceptible A. baumannii isolates. In addition, confocal imaging revealed the predominance of dead cells in the OH-treated samples in comparison to the control. Further, scanning electron microscopy of biofilms formed on catheters revealed that OH treatment significantly reduced A. baumannii biofilm populations in corroboration with our antibiofilm assay. These data underscore the efficacy of OH in inactivating A. baumannii biofilms, thereby suggesting its potential use as a disinfectant or a catheter lock solution to control A. baumannii infections. PMID:27375572

  1. Inactivation of Acinetobacter baumannii Biofilms on Polystyrene, Stainless Steel, and Urinary Catheters by Octenidine Dihydrochloride.

    Science.gov (United States)

    Narayanan, Amoolya; Nair, Meera S; Karumathil, Deepti P; Baskaran, Sangeetha A; Venkitanarayanan, Kumar; Amalaradjou, Mary Anne Roshni

    2016-01-01

    Acinetobacter baumannii is a major nosocomial pathogen causing human infections with significant mortality rates. In most cases, infections are acquired through exposure to A. baumannii biofilms that persist on contaminated hospital equipment and surfaces. Thus, it is imperative to develop effective measures for controlling A. baumannii biofilms in nosocomial settings. This study investigated the efficacy of octenidine dihydrochloride (OH), a new generation disinfectant for reducing A. baumannii biofilms on polystyrene, stainless steel and catheters. OH at 0.3% (5 mM), 0.6% (10 mM), and 0.9% (15 mM) was effective in significantly inactivating A. baumannii biofilms on all tested surfaces (P < 0.05). Furthermore, OH was equally effective in inactivating biofilms of multidrug resistant and drug susceptible A. baumannii isolates. In addition, confocal imaging revealed the predominance of dead cells in the OH-treated samples in comparison to the control. Further, scanning electron microscopy of biofilms formed on catheters revealed that OH treatment significantly reduced A. baumannii biofilm populations in corroboration with our antibiofilm assay. These data underscore the efficacy of OH in inactivating A. baumannii biofilms, thereby suggesting its potential use as a disinfectant or a catheter lock solution to control A. baumannii infections.

  2. Characterization and Detection of Endolysin Gene from Three Acinetobacter baumannii Bacteriophages Isolated from Sewage Water.

    Science.gov (United States)

    Kitti, Thawatchai; Thummeepak, Rapee; Thanwisai, Aunchalee; Boonyodying, Kamala; Kunthalert, Duangkamol; Ritvirool, Pannika; Sitthisak, Sutthirat

    2014-12-01

    Acinetobacter baumannii is an opportunistic pathogen that exists in hospital environments. The emergence of multidrug resistant A. baumannii (MDRAB) has been reported worldwide. It is necessary to find a novel and effective treatment for MDRAB infection. In this study, three bacteriophages, designated as ØABP-01, ØABP-02 and ØABP-04 were selected for analysis. Transmission electron microscopy showed that bacteriophage ØABP-01 belonged to the Podoviridae family and bacteriophage ØABP-02 and ØABP-04 are classified into the family Myoviridae. ØABP-01 had the widest host range. ØABP-01, ØABP-02 and ØABP-04 exhibited a latent period of 15, 20 and 20 min. The burst sizes of the three bacteriophages were 110, 120 and 150 PFU/cell. DNA restriction analysis using EcoRI, HindIII, PstI, SphI, BamHI and SmaI showed different DNA fragment patterns between the three bacteriophages. ØABP-01 and ØABP-04 was positive for the endolysin gene as determined by PCR. In conclusion, bacteriophage ØABP-01 showed broad host-specificity, good lytic activity and a short latency period, making it an appropriate candidate for studying the control and diagnosis associated with MDRAB infections.

  3. Differential Role of the T6SS in Acinetobacter baumannii Virulence.

    Directory of Open Access Journals (Sweden)

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

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    Guang-Huey Lin

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

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

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

    2015-01-01

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

  6. 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%, Pmechanical ventilation for at least 48 hours. Candida spp. airway colonization was an independent risk factor for subsequent A. baumannii VAP. PMID:27001670

  7. The contribution of nutrient metal acquisition and metabolism to Acinetobacter baumannii survival within the host

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    Brittany L Mortensen

    2013-12-01

    Full Text Available Acinetobacter baumannii is a significant contributor to intensive care unit (ICU mortality causing numerous types of infection in this susceptible ICU population, most notably ventilator-associated pneumonia. The substantial disease burden attributed to A. baumannii and the rapid acquisition of antibiotic resistance make this bacterium a serious health care threat. A. baumannii is equipped to tolerate the hostile host environment through modification of its metabolism and nutritional needs. Among these adaptations is the evolution of mechanisms to acquire nutrient metals that are sequestered by the host as a defense against infection. Although all bacteria require nutrient metals, there is diversity in the particular metal needs among species and within varying tissue types and bacterial lifecycles. A. baumannii is well-equipped with the metal homeostatic systems required for the colonization of a diverse array of tissues. Specifically, iron and zinc homeostasis is important for A. baumannii interactions with biotic surfaces and for growth within vertebrates. This review discusses what is currently known regarding the interaction of A. baumannii with vertebrate cells with a particular emphasis on the contributions of metal homeostasis systems. Overall, published research supports the utility of exploiting these systems as targets for the development of much-needed antimicrobials against this emerging infectious threat.

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

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    Chuanfu Zhang

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

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

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    Goel Vikas

    2001-08-01

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

  10. Structure determination of LpxA from the lipopolysaccharide-synthesis pathway of Acinetobacter baumannii.

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

    2012-12-01

    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. PMID:23192027

  11. Protection against Acinetobacter baumannii infection via its functional deprivation of biofilm associated protein (Bap).

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    Fattahian, Yaser; Rasooli, Iraj; Mousavi Gargari, Seyed Latif; Rahbar, Mohammad Reza; Darvish Alipour Astaneh, Shakiba; Amani, Jafar

    2011-12-01

    Acinetobacter baumannii, a major nosocomial pathogen, has remarkable capacity to acquire antimicrobial resistance attributable to its biofilm formation ability. Biofilm associated protein (Bap), a specific cell surface protein, is directly involved in biofilm formation by A. baumannii and plays a major role in bacterial infectious processes. In the present study we cloned, expressed and purified a 371 amino acid subunit of Bap. Mice were immunized using recombinant Bap subunit. They were then challenged with A. baumannii to evaluate the immunogenicity and protectivity of Bap subunit. Humoral immune response to Bap was determined by ELISA. Injection of Bap subunit resulted in high antibody titers. Decrease in bacterial cell counts of the immunized mice was evident 18 h after challenge. Reaction of antibodies against Bap with several strains suggests that not only immunodominant regions of Bap in A. baumannii strains are conserved but also have the same epitope presenting pattern in different strains. Immunodominant region of Bap possesses target sites for a protective humoral immune response to A. baumannii. This seems to be a conserved region erecting efficacy of Bap as an appropriate vaccine candidate.

  12. Prevalence and resistance of Acinetobacter baumannii isolated at Hyatabad Medical Complex, Khyber Pakhtunkhwa, Pakistan

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    Said Hassan

    2016-09-01

    Full Text Available Objective: To assess the resistance against widely used antibiotics in case of Acinetobacter baumannii (A. baumannii infection. Methods: A total of 350 samples of pus, urine, swab and others from different patients were examined and the bacterial growth appeared in 50 samples. Each sample was inoculated on blood, MacConkey and cystine lactose electrolyte deficient agar. The antimicrobial susceptibility profile of the isolates was determined using agar plate method/disk-diffusion method (modified-Kirby Baur disc diffusion method. Results: In current study, a large number of isolates of A. baumannii obtained from different specimens were resistant to avelox (56%, followed by tygacil (46%, augmentin (46%, cefspan (38%, cefixime (24% and ampicillin (20%. However, the antibiogram of A. baumannii also showed that most of the isolates (88% were highly sensitive to cefalexin. Second maximum sensitivity of A. baumannii was seen to amikacin (84%. The sensitivity of isolates against amikacin was followed by ticarcillin (80%. Meronem was found highly active against the tested isolates (78%. Sensitivity was observed for tienem (76%, sulzone (72% followed by azactam (68%, cefobid (66% to cefotaxime (66% and ciproxin (62%. Conclusions: Results elucidate that A. baumannii is a severe problem as it has become a highly resistant species in hospitalized patients and resistant A. baumannii infection turned out to have increased all-cause mortality.

  13. Emergence of Acinetobacter baumannii ST730 carrying the bla OXA-72 gene in Brazil

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    Pagano, Mariana; Rozales, Franciéli P; Bertolini, Diego; Rocha, Lisiane; Sampaio, Jorge LM; Barth, Afonso L; Martins, Andreza F

    2016-01-01

    Over the last decade, Acinetobacter baumannii resistant to carbapenems has emerged in many medical centres and has been commonly associated with high morbimortality. In Brazil, this resistance is mainly attributed to the spread of OXA-23-producing clones and, to a lesser extent, to OXA-143-producing clones. Here, we describe, for the first time, two OXA-72-producing A. baumannii isolates in southern Brazil to a broad spectrum of antibiotics, except polymyxin B and tigecycline. Molecular typing by multilocus sequence typing (MLST) demonstrated that both OXA-72-producing isolates belong to a new sequence type (ST), ST730, which was recently identified in OXA-23-producing A. baumannii isolates in São Paulo, Brazil. We demonstrate that the two A. baumannii ST730 isolates carrying blaOXA-72share a common ancestral origin with the blaOXA-23producers in Brazil. This observation reinforces the importance of strain-typing methods in order to clarify the dynamics of the emergence of new clones in a geographic region. PMID:27653364

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

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

    2016-08-23

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

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

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

    2010-06-01

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

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

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    Cohen Karen

    2009-03-01

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

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

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

    2015-06-01

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

  18. Insights on the Horizontal Gene Transfer of Carbapenemase Determinants in the Opportunistic Pathogen Acinetobacter baumannii

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    Da Silva, Gabriela Jorge; Domingues, Sara

    2016-01-01

    Horizontal gene transfer (HGT) is a driving force to the evolution of bacteria. The fast emergence of antimicrobial resistance reflects the ability of genetic adaptation of pathogens. Acinetobacter baumannii has emerged in the last few decades as an important opportunistic nosocomial pathogen, in part due to its high capacity of acquiring resistance to diverse antibiotic families, including to the so-called last line drugs such as carbapenems. The rampant selective pressure and genetic exchange of resistance genes hinder the effective treatment of resistant infections. A. baumannii uses all the resistance mechanisms to survive against carbapenems but production of carbapenemases are the major mechanism, which may act in synergy with others. A. baumannii appears to use all the mechanisms of gene dissemination. Beyond conjugation, the mostly reported recent studies point to natural transformation, transduction and outer membrane vesicles-mediated transfer as mechanisms that may play a role in carbapenemase determinants spread. Understanding the genetic mobilization of carbapenemase genes is paramount in preventing their dissemination. Here we review the carbapenemases found in A. baumannii and present an overview of the current knowledge of contributions of the various HGT mechanisms to the molecular epidemiology of carbapenem resistance in this relevant opportunistic pathogen.

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

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    zahra eFarshadzadeh

    2015-10-01

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

  20. The antibacterial activity of some essential oils against clinical isolates of Acinetobacter baumannii

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    Mohaddese Mahboubi

    2014-10-01

    Full Text Available Acinetobacter baumannii is categorized as a red alert pathogen that is increasingly associated with a high mortality rate in infected patients due to its resistance to extensive antibiotics. In this study, we evaluated the antibacterial activities of some essential oils (Oliveria decumbens, Pelargonium graveolens, Eugenia caryophyllata, Ziziphora tenuir and Trachyspermum copticum oils against 32 clinical isolates of A. baumannii. The antibacterial evaluations and chemical composition of essential oils was determined. Thymol, eugenol, -terpineol, -citronellol and thymol were the chief portions of T. copticum, E. caryophyllata, Z. tenuir, O. decumbens and P. graveolens oils, respectively. The MIC values of oils against these clinical isolates revealed the three subsets of oils including 1- T. copticum, E. caryophyllata and O. decumbens, 2- Z. tenuir and 3- P. graveolens oils. These oils showed the synergistic activity with amikacin, the lower Fractional Inhibitory Concentration Index (FICI was for P. graveolens oil (0.23 and the higher FICI was for E. caryophyllata (0.325.

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

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    Wan, Guoqing; Ruan, Lingao; Yin, Yu; Yang, Tian; Ge, Mei; Cheng, Xiaodong

    2016-01-01

    Acinetobacter baumannii resistance to carbapenem antibiotics is a serious clinical challenge. As a newly developed technology, silver nanoparticles (AgNPs) show some excellent characteristics compared to older treatments, and are a candidate for combating A. baumannii infection. However, its mechanism of action remains unclear. In this study, we combined AgNPs with antibiotics to treat carbapenem-resistant A. baumannii (aba1604). Our results showed that single AgNPs completely inhibited A. baumannii growth at 2.5 μg/mL. AgNP treatment also showed synergistic effects with the antibiotics polymixin B and rifampicin, and an additive effect with tigecyline. In vivo, we found that AgNPs–antibiotic combinations led to better survival ratios in A. baumannii-infected mouse peritonitis models than that by single drug treatment. Finally, we employed different antisense RNA-targeted Escherichia coli strains to elucidate the synergistic mechanism involved in bacterial responses to AgNPs and antibiotics. PMID:27574420

  2. Bacterial O-methylation of halogen-substituted phenols. [Rhodococcus; Acinetobacter

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    Allard, A.S.; Remberger, M.; Neilson, A.H.

    1987-04-01

    Two strains of bacteria capable of carrying out the O-methylation of phenolic compounds, one from the gram-positive genus Rhodococcus and one from the gram-negative genus Acinetobacter, were used to examine the O-methylation of phenols carrying fluoro-, chloro-, and bromo-substituents. Zero-order rates of O-methylation were calculated from data for the chloro- and bromophenols; there was no simple relationship between the rate of reaction and the structure of the substrates, and significant differences were observed in the responses of the two test organisms. For the gram-negative strain, the pattern of substitution was as important as the number of substituents. Hexachlorophene was resistant to O-methylation by both strains, and tetrabromobisphenol-A was O-methylated only by the gram-positive strain. It is suggested that in the natural environment, bacterial O-methylation of phenols carrying electron-attracting substituents might be a significant alternative to biodegradation.

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

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

    2016-08-01

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

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

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    Micheli Medeiros

    2013-12-01

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

  5. Multidrug resistant Acinetobacter baumannii in veterinary medicine--emergence of an underestimated pathogen?

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    Müller, Stefanie; Janssen, Traute; Wieler, Lothar H

    2014-01-01

    The proportion of multidrug resistant bacteria causing infections in animals has continuously been increasing. While the relevance of ESBL (extended spectrum beta-lactamase)-producing Enterobacteriaceae spp. and MRSA (methicillin resistant Staphylococcus aureus) is unquestionable, knowledge about multidrug resistant Acinetobacter baumannii in veterinary medicine is scarce. This is a worrisome situation, as A. baumannii are isolated from veterinary clinical specimens with rising frequency. The remarkable ability of A. baumannii to develop multidrug resistance and the high risk of transmission are known in human medicine for years. Despite this, data regarding A. baumannii isolates of animal origin are missing. Due to the changing role of companion animals with closer contact between animal and owner, veterinary intensive care medicine is steadily developing. It can be assumed that the number of "high risk" patients with an enhanced risk for hospital acquired infections will be rising simultaneously. Thus, development and spread of multidrug resistant pathogens is envisioned to rise. It is possible, that A. baumannii will evolve into a veterinary nosocomial pathogen similar to ESBL-producing Enterobacteriaceae and MRSA. The lack of attention paid to A. baumannii in veterinary medicine is even more worrying, as first reports indicate a transmission between humans and animals. Essential questions regarding the role of livestock, especially as a potential source of multidrug resistant isolates, remain unanswered. This review summarizes the current knowledge on A. baumannii in veterinary medicine for the first time. It underlines the utmost significance of further investigations of A. baumannii animal isolates, particularly concerning epidemiology and resistance mechanisms.

  6. The Genetic Analysis of an Acinetobacter johnsonii Clinical Strain Evidenced the Presence of Horizontal Genetic Transfer

    Science.gov (United States)

    Montaña, Sabrina; Schramm, Sareda T. J.; Traglia, German Matías; Chiem, Kevin; Parmeciano Di Noto, Gisela; Almuzara, Marisa; Barberis, Claudia; Vay, Carlos; Quiroga, Cecilia; Tolmasky, Marcelo E.; Iriarte, Andrés; Ramírez, María Soledad

    2016-01-01

    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. PMID:27548264

  7. Use of the accessory genome for characterization and typing of Acinetobacter baumannii.

    Science.gov (United States)

    Turton, Jane F; Baddal, Buket; Perry, Claire

    2011-04-01

    Outbreak strains of Acinetobacter baumannii are highly clonal, and cross-infection investigations can be difficult. We sought targets based on AbaR resistance islands and on other genes found in some, but not all, sequenced isolates of A. baumannii among a set of clinical isolates (n = 70) that included multiple representatives of a number of pulsed-field gel electrophoresis (PFGE)-defined types. These included representatives that varied in their profiles at two variable-number tandem repeat (VNTR) loci, which can provide discrimination within a PFGE cluster. Detection, or not, of each element sought provided some degree of discrimination among the set, with the presence or absence of genes coding for a phage terminase (ACICU_02185), a sialic acid synthase (ACICU_00080), a polysaccharide biosynthesis protein (AB57_0094), aphA1, bla(TEM), and integron-associated orfX (Kyoto Encyclopedia of Genes and Genomes [KEGG] no. K03830) proving the most helpful in discriminating between closely related isolates in our panel. The results support VNTR data in describing distinct populations of highly similar isolates. Such analysis, in combination with other typing methods, can inform epidemiological investigations and provide additional characterization of isolates. Most genotypes carrying bla(OXA-23-like) were PCR positive for a yeeA-bla(OXA-23) fragment found in an AbaR4-type island, suggesting that this is widespread.

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

    Institute of Scientific and Technical Information of China (English)

    Xuri Wu; Nan Liu; Yunmian He; Yijun Chen

    2009-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Nassima Djahmi

    2014-01-01

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

  11. Crystal Structure of Hcp from Acinetobacter baumannii: A Component of the Type VI Secretion System.

    Directory of Open Access Journals (Sweden)

    Federico M Ruiz

    Full Text Available The type VI secretion system (T6SS is a bacterial macromolecular machine widely distributed in Gram-negative bacteria, which transports effector proteins into eukaryotic host cells or other bacteria. Membrane complexes and a central tubular structure, which resembles the tail of contractile bacteriophages, compose the T6SS. One of the proteins forming this tube is the hemolysin co-regulated protein (Hcp, which acts as virulence factor, as transporter of effectors and as a chaperone. In this study, we present the structure of Hcp from Acinetobacter baumannii, together with functional and oligomerization studies. The structure of this protein exhibits a tight β barrel formed by two β sheets and flanked at one side by a short α-helix. Six Hcp molecules associate to form a donut-shaped hexamer, as observed in both the crystal structure and solution. These results emphasize the importance of this oligomerization state in this family of proteins, despite the low similarity of sequence among them. The structure presented in this study is the first one for a protein forming part of a functional T6SS from A. baumannii. These results will help us to understand the mechanism and function of this secretion system in this opportunistic nosocomial pathogen.

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

    Science.gov (United States)

    Rasoulinejad, Samaneh; Gargari, Seyed Latif Mousavi

    2016-08-10

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

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

    Directory of Open Access Journals (Sweden)

    Mohan Gurjar

    2013-01-01

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

  14. Productivity of cyclohexanone oxidation of the recombinant Corynebacterium glutamicum expressing chnB of Acinetobacter calcoaceticus.

    Science.gov (United States)

    Doo, Eun-Hee; Lee, Won-Heong; Seo, Hyo-Seel; Seo, Jin-Ho; Park, Jin-Byung

    2009-06-15

    The biocatalytic efficiency of recombinant Corynebacterium glutamicum expressing the chnB gene encoding cyclohexanone monooxygenase (CHMO) of Acinetobacter calcoaceticus NCIMB 9871 was investigated. Optimization of an expression system and induction conditions enabled the recombinant biocatalyst to produce CHMO to a specific activity of ca. 0.5 U mg(-1) protein. Tight control of feeding of an energy source (i.e., glucose) and dissolved oxygen tension during fed-batch culture-based biotransformation allowed the cells to produce epsilon-caprolactone to a concentration of 16.0 g l(-1). The specific and volumetric productivity for cyclohexanone oxidation were 0.12 g g drycells(-1)h(-1) (17.5 U g(-1) of dry cells) and 2.3 g l(-1)h(-1) (330 U l(-1)), respectively. These values correspond to over 5.4- and 2.7-fold of recombinant Escherichia coli expressing the same gene under similar reaction conditions. It could be concluded that the recombinant C. glutamicum is a promising biocatalyst for Baeyer-Villiger oxidations.

  15. Resistance and integron characterization of Acinetobacter baumannii in a teaching hospital in Chongqing, China

    Directory of Open Access Journals (Sweden)

    C. Huang

    2015-11-01

    Full Text Available A total of 189 Acinetobacter baumannii isolates were collected in 2011 from a teaching hospital in Chongqing, China. Susceptibility data showed strains carrying integrons were significantly more resistant to all tested antibiotics that strains lacking integrons. Five types of gene cassettes belonging to class I integrons were identified in this study, and for the first time two types of gene cassettes belonging to class II integrons are reported. Most of the cassettes belong to a class I integron (136/144 encoding arr3, aacA4, dfrA17, aadA5, aadB, cat, blaOXA10, aadA1, aadA2, dfrA and aacC1. Isolates contained a class I gene cassette; AadA2-HP-dfrA was the prevalent strain in this hospital. A class II integron was detected in eight strains, which contained the type IV fimbriae expression regulatory gene pilR and sulfate adenylyltransferase, suggesting a possible role in multidrug resistance. The major epidemic strains from intensive care unit patients belong to international clone 2. In conclusion, the presence of integrons was significantly associated with multiple drug resistance of A. baumannii in this hospital, and class I integron isolates bearing AadA2-HP-dfrA were the prevalent strain in this hospital.

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

    Directory of Open Access Journals (Sweden)

    David Chang

    2016-03-01

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

  17. Biodegradation of malathion by Acinetobacter johnsonii MA19 and optimization of cometabolism substrates

    Institute of Scientific and Technical Information of China (English)

    XIE Shan; LIU Junxin; LI Lin; QIAO Chuanling

    2009-01-01

    To enhance the removal efficiency of malathion in the wastewater from organophosphate pesticide mill, a bacterium, Acinetobacter johnsonii MA19, that could degrade malathion with cometabolism was isolated from malathion-polluted soil samples using enrichment culture techniques. Four kinds of additional compounds, sodium succinate, sodium acetate, glucose, and fructose were tested to choose a favorite carbon source for the cometabolism of strain MA19. The results showed that sodium succinate and sodium acetate could promote malathion biodegradation and cell growth. The investigation results of effects of sodium succinate concentrations on the malathion biodegradation indicated that the more sodium succinate supplied resulted in quick degradation ofmalathion and fast cells multiplied. Zero-order kinetic model was appropriate to describe the malathion biodegradation when the concentration of sodium succinate was more than 0.5144 g/L. The degradation rate constant (K) reached the maximum value of 3.5837 mg/(L·h) when the mass ratio of sodium succinate to malathion was 128.6 mg/mg. The aquatic toxicity of the malathion was evaluated using the test organism, Limnodrilus hoffmeisteri. The data obtained suggested that the toxicity of malathion could be ignored after 84 h biodegradation. Our result demonstrates the potential for using bacterium A. Johnsonii MA19 for malathion biodegradation and environmental bioremediation when some suitable conventional carbon sources are supplied.

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

    Science.gov (United States)

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

    2012-06-01

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

  19. Bradysia sp. em morangueiro Bradysia sp. in strawberry

    Directory of Open Access Journals (Sweden)

    Bernadete Radin

    2009-04-01

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

  20. SP-100 advanced technology program

    International Nuclear Information System (INIS)

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

  1. Síndrome séptico por Acinetobacter calcoaceticus, variedad anitratus Septic syndrome due to acinetobacter calcoaceticus var. anitratus in an infant: report of a case and review of the subject

    Directory of Open Access Journals (Sweden)

    Carmen Tulia Zapata Muñoz

    1994-04-01

    Full Text Available Se presenta un caso de síndrome séptico por Acinetobacter calcoaceticus, variedad anitratus, adquirido en la comunidad por un niño inmunocompetente. Esta combinación de circunstancias es inusitada. Se manifestó por meningitis, compromiso del pulmón izquierdo y un absceso glúteo. El niño se recuperó completamente con la antibioterapia. Se propone éste como el primer caso informado en la literatura latinoamericana que reúne las condiciones anotadas. Se hace una síntesis de las características generales de la bacteria, la patogénesis de la infección y las principales enfermedades que produce, así como los medios existentes para prevenirla.

    We report on the case of an immunocompetent infant who presented with a septic syndrome due to a community-acquired infection by Acinetobacter calcoaceticus var. anitratus. Clinical manifestations were meningitis, left Iobar pneumonia with pleural effussion and a gluteal ascess. The patient fully recovered with antibiotic therapy. This case may be the first in the Latin-American medical literature with such unusual combination of features. A review is presented on the general characteristics of Acinetobacter, the pathogenesis of the infections It produces, the main clinical presentations and the methods of prevention.

  2. En moderne spøgelseshistorie

    DEFF Research Database (Denmark)

    Simonsen, Karen-Margrethe

    2011-01-01

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

  3. Optimal spænding i kajakken

    DEFF Research Database (Denmark)

    Rossing, Niels Nygaard

    2012-01-01

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

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

    OpenAIRE

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

    2010-01-01

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

  5. 101株鲍曼不动杆菌的耐药性分析%Analysis of drug resistance of acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    王仲书; 李玉梅; 王灿灿

    2011-01-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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

  9. Penicillium araracuarense sp. nov., Penicillium elleniae sp. nov., Penicillium penarojense sp. nov., Penicillium vanderhammenii sp. nov. and Penicillium wotroi sp. nov., isolated from leaf litter

    DEFF Research Database (Denmark)

    Houbraken, Jos; López-Quintero, Carlos A.; Frisvad, Jens Christian;

    2011-01-01

    Several species of the genus Penicillium were isolated during a survey of the mycobiota of leaf litter and soil in Colombian Amazon forest. Five species, Penicillium penarojense sp. nov. (type strain CBS 113178T = IBT 23262T), Penicillium wotroi sp. nov. (type strain CBS 118171T = IBT 23253T......), Penicillium araracuarense sp. nov. (type strain CBS 113149T = IBT 23247T), Penicillium elleniae sp. nov. (type strain CBS 118135T = IBT 23229T) and Penicillium vanderhammenii sp. nov. (type strain CBS 126216T = IBT 23203T) are described here as novel species. Their taxonomic novelty was determined using...... a polyphasic approach, combining phenotypic, molecular (ITS and partial β-tubulin sequences) and extrolite data. Phylogenetic analyses showed that each novel species formed a unique clade for both loci analysed and that they were most closely related to Penicillium simplicissimum, Penicillium janthinellum...

  10. NDM-1-Producing Citrobacter freundii, Escherichia coli, and Acinetobacter baumannii Identified from a Single Patient in China.

    Science.gov (United States)

    Huang, Ying-Min; Zhong, Lan-Lan; Zhang, Xue-Fei; Hu, Hang-Tong; Li, Yu-Qi; Yang, Xiao-Rong; Feng, Lian-Qiang; Huang, Xi; Tian, Guo-Bao

    2015-08-01

    We identified New Delhi metallo-β-lactamase (NDM-1)-producing Citrobacter freundii GB032, Escherichia coli GB102, and Acinetobacter baumannii GB661 in urine and stool samples from a single patient in China. Plasmid profiling and Southern blotting indicated that blaNDM-1 from GB032 and that from GB102 were likely located on the same plasmid, while blaNDM-1 from GB661 was located on a very large (>400-kb) plasmid. This case underscores the broad host range of blaNDM-1 and its potential to spread between members of the family Enterobacteriaceae and A. baumannii.

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

    OpenAIRE

    Hong, Hyerim; Jung, Jaejoon; Park, Woojun

    2014-01-01

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

  12. Characterization of eDNA from the Clinical Strain Acinetobacter baumannii AIIMS 7 and Its Role in Biofilm Formation

    OpenAIRE

    Sahu, Praveen K.; Iyer, Pavithra S.; Amrita M. Oak; Pardesi, Karishma R.; Chopade, Balu A.

    2012-01-01

    Release of extracellular DNA (eDNA) was observed during in vitro growth of a clinical strain of Acinetobacter baumannii. Membrane vesicles (MV) of varying diameter (20–200 nm) containing DNA were found to be released by transmission electron microscopy (TEM) and atomic force microscopy (AFM). An assessment of the characteristics of the eDNA with respect to size, digestion pattern by DNase I/restriction enzymes, and PCR-sequencing, indicates a high similarity with genomic DNA. Role of eDNA in ...

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

    OpenAIRE

    Goel Vikas; Kapil Arti

    2001-01-01

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

  14. 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.

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

    OpenAIRE

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

    2014-01-01

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

  16. Genes encoding OXA-134-like enzymes are found in Acinetobacter lwoffii and A. schindleri and can be used for identification.

    Science.gov (United States)

    Turton, Jane F; Hyde, Rhiannon; Martin, Kate; Shah, Jayesh

    2012-03-01

    bla(OXA-134) genes and variants were sought in 21 species of Acinetobacter and found in A. lwoffii, genomic species 9 (regarded as synonyms), and A. schindleri. Sequencing revealed a 9-bp deletion in the gene in the type strain of genomic species 9 (ATCC 9957) relative to the gene in the type strain of A. lwoffii (ATCC 15309). Primers based on the gene without the deletion gave specific amplification of 29 of 30 clinical isolates of A. lwoffii/genomic species 9.

  17. Draft genome sequence of a multidrug-resistant blaOXA-23-producing Acinetobacter baumannii ST208 isolate from China.

    Science.gov (United States)

    Chen, Yan; Wu, Liyan; Chen, Yu; Xu, Zhijun; Xu, Liqun

    2016-03-01

    Acinetobacter baumannii has emerged worldwide as an important opportunistic nosocomial pathogen and has become a major public health concern. In this study, the draft genome sequence of A. baumannii TCM331 (ST208/CC92), a multidrug-resistant (MDR) isolate harbouring the blaOXA-23 gene isolated in China, was determined. The genome of TCM331 was sequenced via Illumina HiSeq™ 2000, and bioinformatics analysis was performed. Important antimicrobial resistance determinants were observed in an estimated genome size of 4,058,691bp with 3838 predicted coding regions. In conclusion, these data might facilitate further understanding of the specific genomic features of MDR A. baumannii in China.

  18. 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. PMID:26778130

  19. The Response Regulator BfmR Is a Potential Drug Target for Acinetobacter baumannii.

    Science.gov (United States)

    Russo, Thomas A; Manohar, Akshay; Beanan, Janet M; Olson, Ruth; MacDonald, Ulrike; Graham, Jessica; Umland, Timothy C

    2016-01-01

    Identification and validation is the first phase of target-based antimicrobial development. BfmR (RstA), a response regulator in a two-component signal transduction system (TCS) in Acinetobacter baumannii, is an intriguing potential antimicrobial target. A unique characteristic of BfmR is that its inhibition would have the dual benefit of significantly decreasing in vivo survival and increasing sensitivity to selected antimicrobials. Studies on the clinically relevant strain AB307-0294 have shown BfmR to be essential in vivo. Here, we demonstrate that this phenotype in strains AB307-0294 and AB908 is mediated, in part, by enabling growth in human ascites fluid and serum. Further, BfmR conferred resistance to complement-mediated bactericidal activity that was independent of capsular polysaccharide. Importantly, BfmR also increased resistance to the clinically important antimicrobials meropenem and colistin. BfmR was highly conserved among A. baumannii strains. The crystal structure of the receiver domain of BfmR was determined, lending insight into putative ligand binding sites. This enabled an in silico ligand binding analysis and a blind docking strategy to assess use as a potential druggable target. Predicted binding hot spots exist at the homodimer interface and the phosphorylation site. These data support pursuing the next step in the development process, which includes determining the degree of inhibition needed to impact growth/survival and the development a BfmR activity assay amenable to high-throughput screening for the identification of inhibitors. Such agents would represent a new class of antimicrobials active against A. baumannii which could be active against other Gram-negative bacilli that possess a TCS with shared homology. IMPORTANCE Increasing antibiotic resistance in bacteria, particularly Gram-negative bacilli, has significantly affected the ability of physicians to treat infections, with resultant increased morbidity, mortality, and health

  20. Outbreak of resistant Acinetobacter baumannii: measures and proposal for prevention and control

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    Roberta Maia de Castro Romanelli

    2009-10-01

    Full Text Available Acinetobacter baumannii colonization and infection, frequent in Intensive Care Unit (ICU patients, is commonly associated with high morbimortality. Several outbreaks due to multidrug-resistant (MDR A. baumanii have been reported but few of them in Brazil. This study aimed to identify risk factors associated with colonization and infection by MDR and carbapenem-resistant A. baumannii strains isolated from patients admitted to the adult ICU at HC/UFMG. A case-control study was performed from January 2007 to June 2008. Cases were defined as patients colonized or infected by MDR/carbapenem-resistant A. baumannii, and controls were patients without MDR/carbapenem-resistant A. baumannii isolation, in a 1:2 proportion. For statistical analysis, due to changes in infection control guidelines, infection criteria and the notification process, this study was divided into two periods. During the first period analyzed, from January to December 2007, colonization or infection by MDR/carbapenem-resistant A. baumannii was associated with prior infection, invasive device utilization, prior carbapenem use and clinical severity. In the multivariate analysis, prior infection and mechanical ventilation proved to be statistically significant risk factors. Carbapenem use showed a tendency towards a statistical association. During the second study period, from January to June 2008, variables with a significant association with MDR/carbapenem-resistant A. baumannii colonization/infection were catheter utilization, carbapenem and third-generation cephalosporin use, hepatic transplantation, and clinical severity. In the multivariate analysis, only CVC use showed a statistical difference. Carbapenem and third-generation cephalosporin use displayed a tendency to be risk factors. Risk factors must be focused on infection control and prevention measures considering A. baumanni dissemination.

  1. Personalized Therapeutic Cocktail of Wild Environmental Phages Rescues Mice from Acinetobacter baumannii Wound Infections.

    Science.gov (United States)

    Regeimbal, James M; Jacobs, Anna C; Corey, Brendan W; Henry, Matthew S; Thompson, Mitchell G; Pavlicek, Rebecca L; Quinones, Javier; Hannah, Ryan M; Ghebremedhin, Meron; Crane, Nicole J; Zurawski, Daniel V; Teneza-Mora, Nimfa C; Biswas, Biswajit; Hall, Eric R

    2016-10-01

    Multidrug-resistant bacterial pathogens are an increasing threat to public health, and lytic bacteriophages have reemerged as a potential therapeutic option. In this work, we isolated and assembled a five-member cocktail of wild phages against Acinetobacter baumannii and demonstrated therapeutic efficacy in a mouse full-thickness dorsal infected wound model. The cocktail lowers the bioburden in the wound, prevents the spread of infection and necrosis to surrounding tissue, and decreases infection-associated morbidity. Interestingly, this effective cocktail is composed of four phages that do not kill the parent strain of the infection and one phage that simply delays bacterial growth in vitro via a strong but incomplete selection event. The cocktail here appears to function in a combinatorial manner, as one constituent phage targets capsulated A. baumannii bacteria and selects for loss of receptor, shifting the population to an uncapsulated state that is then sensitized to the remaining four phages in the cocktail. Additionally, capsule is a known virulence factor for A. baumannii, and we demonstrated that the emergent uncapsulated bacteria are avirulent in a Galleria mellonella model. These results highlight the importance of anticipating population changes during phage therapy and designing intelligent cocktails to control emergent strains, as well as the benefits of using phages that target virulence factors. Because of the efficacy of this cocktail isolated from a limited environmental pool, we have established a pipeline for developing new phage therapeutics against additional clinically relevant multidrug-resistant pathogens by using environmental phages sourced from around the globe. PMID:27431214

  2. Clonal evolution multi-drug resistant Acinetobacter baumannii by pulsed-field gel electrophoresis

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    P Mohajeri

    2015-01-01

    Full Text Available Background: Acinetobacter baumannii is usually multi-drug resistant (MDR, including third generation cephalosporins, amino glycosides and fluoroquinolone. Resistance to these antibiotics is mediated by multiple factors such as: lactamases, efflux pumps and other mechanisms of resistance. Pulsed-field gel electrophoresis (PFGE was then used to investigate the genetic relationships among the MDR isolates. Aim: The aim of this study was to determine MDR isolates and the existence of OXAs genes among MDR isolates of A. baumannii collected from Kermanshah hospitals in west of Iran. Materials and Methods: Forty-two MDR A. baumannii were collected from patients at Kermanshah hospitals. The isolates were identified by biochemical tests and API 20NE kit. The susceptibility to different antibiotics by disk diffusion method was determined. Polymerase chain reaction (PCR was performed for detection of blaOXA-23-like , blaOXA-24-like , blaOXA-51-like and blaOXA-58-like betalactamase genes in isolates and clonal relatedness was done by PFGE (with the restriction enzyme ApaI and patterns analyzed by Bionumeric software. Results: This study showed high resistant to ciprofloxacin, piperacillin, ceftazidime and also resistant to other anti-microbial agents and more spread blaOXA-23-like gene (93% in MDR isolate. The PFGE method obtained six clones: A (10, B (9, C (5, D (4, E (11 and F (3 that clone E was outbreak and dominant in different wards of hospitals studied. Conclusion: An isolate from the emergency ward of these hospitals had indistinguishable isolates PFGE profile and similar resistance profile to isolates from intensive care unit (ICU, suggesting likely transmission from ICU to emergency via patient or hospital staff contact.

  3. Synergistic effects of sulbactam in multi-drug-resistant Acinetobacter baumannii

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    Fatih Temocin

    2015-12-01

    Full Text Available Abstract Acinetobacter baumannii is a frequently isolated etiologic agent of nosocomial infections, especially in intensive care units. With the increase in multi-drug resistance of A. baumannii isolates, finding appropriate treatment alternatives for infections caused by these bacteria has become more difficult, and available alternate treatments include the use of older antibiotics such as colistin or a combination of antibiotics. The current study aimed to evaluate the in vitro efficacy of various antibiotic combinations against multi-drug resistant A. baumannii strains. Thirty multi-drug and carbapenem resistant A. baumannii strains isolated at the Ankara Training and Research Hospital between June 2011 and June 2012 were used in the study. Antibiotic susceptibility tests and species-level identification were performed using conventional methods and the VITEK 2 system. The effects of meropenem, ciprofloxacin, amikacin, tigecycline, and colistin alone and in combination with sulbactam against the isolates were studied using Etest (bioMérieux in Mueller-Hinton agar medium. Fractional inhibitory concentration index (FIC was used to determine the efficacy of the various combinations. While all combinations showed a predominant indifferent effect, a synergistic effect was also observed in 4 of the 5 combinations. Synergy was demonstrated in 43% of the isolates with the meropenem-sulbactam combination, in 27% of the isolates with tigecycline-sulbactam, and in 17% of the isolates with colistin-sulbactam and amikacin-sulbactam. No synergy was detected with the sulbactam-ciprofloxacin combination and antagonism was detected only in the sulbactam-colistin combination (6.66% of the isolates. Antibiotic combinations can be used as an alternative treatment approach in multi-drug resistant A. baumannii infections.

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

    Science.gov (United States)

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

    2015-05-15

    The traditional markerless gene deletion technique based on overlap extension PCR has been used for generating gene deletions in multidrug-resistant Acinetobacter baumannii. However, the method is time-consuming because it requires restriction digestion of the PCR products in DNA cloning and the construction of new vectors containing a suitable antibiotic resistance cassette for the selection of A. baumannii merodiploids. Moreover, the availability of restriction sites and the selection of recombinant bacteria harboring the desired chimeric plasmid are limited, making the construction of a chimeric plasmid more difficult. We describe a rapid and easy cloning method for markerless gene deletion in A. baumannii, which has no limitation in the availability of restriction sites and allows for easy selection of the clones carrying the desired chimeric plasmid. Notably, it is not necessary to construct new vectors in our method. This method utilizes direct cloning of blunt-end DNA fragments, in which upstream and downstream regions of the target gene are fused with an antibiotic resistance cassette via overlap extension PCR and are inserted into a blunt-end suicide vector developed for blunt-end cloning. Importantly, the antibiotic resistance cassette is placed outside the downstream region in order to enable easy selection of the recombinants carrying the desired plasmid, to eliminate the antibiotic resistance cassette via homologous recombination, and to avoid the necessity of constructing new vectors. This strategy was successfully applied to functional analysis of the genes associated with iron acquisition by A. baumannii ATCC 19606 and to ompA gene deletion in other A. baumannii strains. Consequently, the proposed method is invaluable for markerless gene deletion in multidrug-resistant A. baumannii. PMID:25746991

  5. Identification of New Delhi metallo-β-lactamase 1 in Acinetobacter lwoffii of food animal origin.

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    Yang Wang

    Full Text Available BACKGROUND: To investigate the presence of metallo-β-lactamase (MBL genes and the genetic environment of the New Delhi metallo-β-lactamase gene bla(NDM-1 in bacteria of food animal origin. METHODOLOGY/PRINCIPAL FINDINGS: Gram-negative bacteria with low susceptibility to imipenem (MIC>8 µg/mL were isolated from swab samples collected from 15 animal farms and one slaughterhouse in eastern China. These bacteria were selected for phenotypic and molecular detection of known MBL genes and antimicrobial susceptibility testing. For the bla(NDM-1 positive isolate, conjugation and transformation experiments were carried out to assess plasmid transfer. Southern blotting was conducted to localize the bla(NDM-1 genes, and DNA sequencing was performed to determine the sequences of bla(NDM-1 and the flanking genes. In total, nine gram-negative bacteria of four different species presented a MBL phenotype. bla(NDM-1 was identified on a mobile plasmid named pAL-01 in an Acinetobacter lwoffii isolate of chicken origin. Transfer of pAL-01 from this isolate to E. coli J53 and JM109 resulted in resistance to multiple β-lactams. Sequence analysis revealed that the bla(NDM-1 gene is attached to an intact insertion element ISAba125, whose right inverted repeat (IR-R overlaps with the promoter sequence of bla(NDM-1. Thus, insertion of ISAba125 likely enhances the expression of bla(NDM-1. CONCLUSION: The identification of a bla(NDM-1- carrying strain of A. lwoffii in chickens suggests the potential for zoonotic transmission of bla(NDM-1 and has important implications for food safety.

  6. Resistance Markers and Genetic Diversity in Acinetobacter baumannii Strains Recovered from Nosocomial Bloodstream Infections

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    Hanoch S. I. Martins

    2014-01-01

    Full Text Available In this study, phenotypic and genotypic methods were used to detect metallo-β-lactamases, cephalosporinases and oxacillinases and to assess genetic diversity among 64 multiresistant Acinetobacter baumannii strains recovered from blood cultures in five different hospitals in Brazil from December 2008 to June 2009. High rates of resistance to imipenem (93.75% and polymyxin B (39.06% were observed using the disk diffusion (DD method and by determining the minimum inhibitory concentration (MIC. Using the disk approximation method, thirty-nine strains (60.9% were phenotypically positive for class D enzymes, and 51 strains (79.6% were positive for cephalosporinase (AmpC. Using the E-test, 60 strains (93.75% were positive for metallo-β-lactamases (MβLs. All strains were positive for at least one of the 10 studied genes; 59 (92.1% contained blaVIM-1, 79.6% contained blaAmpC, 93.7% contained blaOXA23 and 84.3% contained blaOXA51. Enterobacteria Repetitive Intergenic Consensus (ERIC-PCR analysis revealed a predominance of certain clones that differed from each other. However, the same band pattern was observed in samples from the different hospitals studied, demonstrating correlation between the genotypic and phenotypic results. Thus, ERIC-PCR is an appropriate method for rapidly clustering genetically related isolates. These results suggest that defined clonal clusters are circulating within the studied hospitals. These results also show that the prevalence of MDR A. baumannii may vary among clones disseminated in specific hospitals, and they emphasize the importance of adhering to appropriate infection control measures.

  7. Epidemiologic and clinical impact of Acinetobacter baumannii colonization and infection: a reappraisal.

    Science.gov (United States)

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

    2014-07-01

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

  8. Clinical epidemiology and resistance mechanisms of carbapenem-resistant Acinetobacter baumannii, French Guiana, 2008-2014.

    Science.gov (United States)

    Mahamat, Aba; Bertrand, Xavier; Moreau, Brigitte; Hommel, Didier; Couppie, Pierre; Simonnet, Christine; Kallel, Hatem; Demar, Magalie; Djossou, Felix; Nacher, Mathieu

    2016-07-01

    This study investigated the clinical epidemiology and resistance mechanisms of Acinetobacter baumannii and characterised the clonal diversity of carbapenem-resistant A. baumannii (CRAB) during an ICU-associated outbreak at Cayenne Hospital, French Guiana. All non-duplicate A. baumannii isolates from 2008 to 2014 were tested for antibiotic susceptibility by disk diffusion. Multilocus sequence typing, pulsed-field gel electrophoresis (PFGE) and characterisation of carbapenemase-encoding genes were performed on CRAB. Of the 441 A. baumannii isolates, most were from males (54.0%) and were detected mainly from the ICU (30.8%) and medicine wards (21.8%). In the ICU, strains were mainly isolated from the respiratory tract (44.1%) and bloodstream (14.0%), whereas in medicine wards they mainly were from wound/drainage (36.5%) and bloodstream (25.0%). A. baumannii showed the greatest susceptibility to piperacillin/tazobactam (92.7%), imipenem (92.5%), colistin (95.6%) and amikacin (97.2%), being lower in the ICU and medicine wards compared with other wards. An outbreak of OXA-23-producing CRAB occurred in the 13-bed ICU in 2010. CRAB strains were more co-resistant to other antimicrobials compared with non-CRAB. Molecular genetics analysis revealed five sequence types [ST78, ST107 and ST642 and two new STs (ST830 and ST831)]. Analysis of PFGE profiles indicated cross-transmissions of CRAB within the ICU, between the ICU and one medicine ward during transfer of patients, and within that medicine ward. This study provides the first clinical and molecular data of A. baumannii from French Guiana and the Amazon basin. The ICU was the highest risk unit of this nosocomial outbreak of OXA-23-producing CRAB, which could subsequently disseminate within the hospital.

  9. Characterising the Transmission Dynamics of Acinetobacter baumannii in Intensive Care Units Using Hidden Markov Models.

    Science.gov (United States)

    Doan, Tan N; Kong, David C M; Marshall, Caroline; Kirkpatrick, Carl M J; McBryde, Emma S

    2015-01-01

    Little is known about the transmission dynamics of Acinetobacter baumannii in hospitals, despite such information being critical for designing effective infection control measures. In the absence of comprehensive epidemiological data, mathematical modelling is an attractive approach to understanding transmission process. The statistical challenge in estimating transmission parameters from infection data arises from the fact that most patients are colonised asymptomatically and therefore the transmission process is not fully observed. Hidden Markov models (HMMs) can overcome this problem. We developed a continuous-time structured HMM to characterise the transmission dynamics, and to quantify the relative importance of different acquisition sources of A. baumannii in intensive care units (ICUs) in three hospitals in Melbourne, Australia. The hidden states were the total number of patients colonised with A. baumannii (both detected and undetected). The model input was monthly incidence data of the number of detected colonised patients (observations). A Bayesian framework with Markov chain Monte Carlo algorithm was used for parameter estimations. We estimated that 96-98% of acquisition in Hospital 1 and 3 was due to cross-transmission between patients; whereas most colonisation in Hospital 2 was due to other sources (sporadic acquisition). On average, it takes 20 and 31 days for each susceptible individual in Hospital 1 and Hospital 3 to become colonised as a result of cross-transmission, respectively; whereas it takes 17 days to observe one new colonisation from sporadic acquisition in Hospital 2. The basic reproduction ratio (R0) for Hospital 1, 2 and 3 was 1.5, 0.02 and 1.6, respectively. Our study is the first to characterise the transmission dynamics of A. baumannii using mathematical modelling. We showed that HMMs can be applied to sparse hospital infection data to estimate transmission parameters despite unobserved events and imperfect detection of the organism

  10. Characterising the Transmission Dynamics of Acinetobacter baumannii in Intensive Care Units Using Hidden Markov Models.

    Directory of Open Access Journals (Sweden)

    Tan N Doan

    Full Text Available Little is known about the transmission dynamics of Acinetobacter baumannii in hospitals, despite such information being critical for designing effective infection control measures. In the absence of comprehensive epidemiological data, mathematical modelling is an attractive approach to understanding transmission process. The statistical challenge in estimating transmission parameters from infection data arises from the fact that most patients are colonised asymptomatically and therefore the transmission process is not fully observed. Hidden Markov models (HMMs can overcome this problem. We developed a continuous-time structured HMM to characterise the transmission dynamics, and to quantify the relative importance of different acquisition sources of A. baumannii in intensive care units (ICUs in three hospitals in Melbourne, Australia. The hidden states were the total number of patients colonised with A. baumannii (both detected and undetected. The model input was monthly incidence data of the number of detected colonised patients (observations. A Bayesian framework with Markov chain Monte Carlo algorithm was used for parameter estimations. We estimated that 96-98% of acquisition in Hospital 1 and 3 was due to cross-transmission between patients; whereas most colonisation in Hospital 2 was due to other sources (sporadic acquisition. On average, it takes 20 and 31 days for each susceptible individual in Hospital 1 and Hospital 3 to become colonised as a result of cross-transmission, respectively; whereas it takes 17 days to observe one new colonisation from sporadic acquisition in Hospital 2. The basic reproduction ratio (R0 for Hospital 1, 2 and 3 was 1.5, 0.02 and 1.6, respectively. Our study is the first to characterise the transmission dynamics of A. baumannii using mathematical modelling. We showed that HMMs can be applied to sparse hospital infection data to estimate transmission parameters despite unobserved events and imperfect detection of

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

    Science.gov (United States)

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

    2016-05-01

    Infection with carbapenem-resistant Acinetobacter baumannii (CRAB) after liver transplantation (LT) is associated with high mortality. This study aimed to identify risk factors for post-LT CRAB infection, as well as to evaluate the impact of pre-LT CRAB acquisition on the incidence of post-LT CRAB infection. This was a prospective cohort study of all patients undergoing LT at our facility between October 2009 and October 2011. Surveillance cultures (SCs) were collected immediately before LT and weekly thereafter, until discharge. We analyzed 196 patients who were submitted to 222 LTs. CRAB was identified in 105 (53.6%); 24 (22.9%) of these patients were found to have acquired CRAB before LT, and 85 (81.0%) tested positive on SCs. Post-LT CRAB infection occurred in 56 (28.6%), the most common site being the surgical wound. Multivariate analysis showed that the risk factors for developing CRAB infection were prolonged cold ischemia, post-LT dialysis, LT due to fulminant hepatitis, and pre-LT CRAB acquisition with pre-LT CRAB acquisition showing a considerable trend toward significance (P = 0.06). Among the recipients with CRAB infection, 60-day mortality was 46.4%, significantly higher than among those without (P < 0.001). Mortality risk factors were post-LT infection with multidrug-resistant bacteria, LT performed because of fulminant hepatitis, retransplantation, prolonged cold ischemia, longer LT surgical time, and pre-LT CRAB acquisition, the last showing a trend toward significance (P = 0.08). In conclusion, pre-LT CRAB acquisition appears to increase the risk of post-LT CRAB infection, which has a negative impact on recipient survival. Liver Transplantation 22 615-626 2016 AASLD.

  12. 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.

  13. Identifying more epidemic clones during a hospital outbreak of multidrug-resistant Acinetobacter baumannii.

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    Matthieu Domenech de Cellès

    Full Text Available Infections caused by multidrug-resistant bacteria are a major concern in hospitals. Current infection-control practices legitimately focus on hygiene and appropriate use of antibiotics. However, little is known about the intrinsic abilities of some bacterial strains to cause outbreaks. They can be measured at a population level by the pathogen's transmission rate, i.e. the rate at which the pathogen is transmitted from colonized hosts to susceptible hosts, or its reproduction number, counting the number of secondary cases per infected/colonized host. We collected data covering a 20-month surveillance period for carriage of multidrug-resistant Acinetobacter baumannii (MDRAB in a surgery ward. All isolates were subjected to molecular fingerprinting, and a cluster analysis of profiles was performed to identify clonal groups. We then applied stochastic transmission models to infer transmission rates of MDRAB and each MDRAB clone. Molecular fingerprinting indicated that 3 clonal complexes spread in the ward. A first model, not accounting for different clones, quantified the level of in-ward cross-transmission, with an estimated transmission rate of 0.03/day (95% credible interval [0.012-0.049] and a single-admission reproduction number of 0.61 [0.30-1.02]. The second model, accounting for different clones, suggested an enhanced transmissibility of clone 3 (transmission rate 0.047/day [0.018-0.091], with a single-admission reproduction number of 0.81 [0.30-1.56]. Clones 1 and 2 had comparable transmission rates (respectively, 0.016 [0.001-0.045], 0.014 [0.001-0.045]. The method used is broadly applicable to other nosocomial pathogens, as long as surveillance data and genotyping information are available. Building on these results, more epidemic clones could be identified, and could lead to follow-up studies dissecting the functional basis for variation in transmissibility of MDRAB lineages.

  14. Predictors of mortality in patients with extensively drug-resistant Acinetobacter baumannii pneumonia receiving colistin therapy.

    Science.gov (United States)

    Choi, Ik Sung; Lee, Yu Ji; Wi, Yu Mi; Kwan, Byung Soo; Jung, Kae Hwa; Hong, Woong Pyo; Kim, June Myong

    2016-08-01

    The ratio of the area under the free (unbound) concentration-time curve to minimum inhibitory concentration (fAUC/MIC) was proposed to be the pharmacokinetic/pharmacodynamic index most strongly linked to the antibacterial effect of colistin against Acinetobacter baumannii. A retrospective study of patients who received colistin to treat pneumonia caused by extensively drug-resistant (XDR) A. baumannii over a 4-year period was performed to assess the impact of the colistin MIC on mortality. A total of 227 patients were included in the analysis. The 7-day and 14-day mortality rates of patients with XDR A. baumannii pneumonia receiving colistin therapy were 15.0% and 23.8%, respectively. In the multivariate analysis, Acute Physiology and Chronic Health Evaluation (APACHE) II score, days from index culture to first dose of colistin, underlying tumour and septic shock at presentation were independent predictors of mortality in patients with XDR A. baumannii pneumonia receiving colistin therapy. In the univariate analysis, the colistin dose based on ideal body weight (IBW) correlated with patient outcome. Therefore, the use of IBW appeared to be more appropriate to calculate the colistin dosage. In addition, these results highlight the clinical significance of colistin MIC in patients with XDR A. baumannii pneumonia receiving colistin therapy. Although MICs were in the 'susceptible' range, patients infected with isolates with high colistin MICs showed a poorer clinical response rate than patients infected with isolates with low colistin MICs. Further clinical studies are needed to evaluate the roles of colistin MIC for predicting mortality in XDR A. baumannii pneumonia with a high colistin MIC. PMID:27423416

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

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    J.-M. Rolain

    2016-05-01

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

  16. Strategies for the treatment of polymyxin B-resistant Acinetobacter baumannii infections.

    Science.gov (United States)

    Menegucci, Thatiany Cevallos; Albiero, James; Migliorini, Letícia Busato; Alves, Janio Leal Borges; Viana, Giselle Fukita; Mazucheli, Josmar; Carrara-Marroni, Floristher Elaine; Cardoso, Celso Luiz; Tognim, Maria Cristina Bronharo

    2016-05-01

    In this study, the activity of meropenem (MEM), fosfomycin (FOF) and polymyxin B (PMB), alone and in combination, was analysed. In addition, optimisation of the pharmacodynamic index of MEM and FOF against six isolates of OXA-23-producing Acinetobacter baumannii (including three resistant to PMB) that were not clonally related was assessed. Antimicrobial combinations were evaluated by chequerboard analysis and were considered synergistic when the fractional inhibitory concentration index (FICI) was ≤0.5. Pharmacodynamic analyses of the MEM and FOF dosing schemes were performed by Monte Carlo simulation. The target pharmacodynamic index (%ƒT>MIC) for MEM and FOF was ≥40% and ≥70%, respectively, and a probability of target attainment (PTA) ≥0.9 was considered adequate. Among the PMB-resistant isolates, combinations of PMB+MEM and PMB+FOF+MEM showed the highest synergistic activity (FICI ≤0.125); isolates that were previously PMB-resistant were included in the susceptible category using CLSI interpretive criteria. Pharmacodynamic evaluation found that for a FOF minimum inhibitory concentration (MIC) of ≤16μg/mL, treatment both by bolus dosing and prolonged infusion achieved adequate PTA, whilst for MIC=32μg/mL only infusion achieved adequate PTA. For a MEM MIC of 4μg/mL, only the bolus treatment scheme with 1.5g q6h and the infusion schemes with 1.0g q8h, 1.5g q6h and 2.0g q8h achieved PTA ≥0.9. Results of antimicrobial and pharmacodynamic analyses can assist in treating infections caused by multidrug-resistant A. baumannii. However, in vivo clinical studies are essential to evaluate the true role of these compounds, including intravenous antimicrobial FOF therapy. PMID:27068675

  17. A meta-analysis of in vitro antibiotic synergy against Acinetobacter baumannii.

    Science.gov (United States)

    March, Gabriel A; Bratos, Miguel A

    2015-12-01

    The aim of the work was to describe the different in vitro models for testing synergism of antibiotics and gather the results of antibiotic synergy against multidrug-resistant Acinetobacter baumannii (MDR-Ab). The different original articles were obtained from different web sites. In order to compare the results obtained by the different methods for synergy testing, the Pearson chi-square and the Fischer tests were used. Moreover, non-parametric chi-square test was used in order to compare the frequency distribution in each analysed manuscript. In the current meta-analysis 24 manuscripts, which encompassed 2016 tests of in vitro synergism of different antimicrobials against MDR-Ab, were revised. Checkerboard synergy testing was used in 11 studies, which encompasses 1086 tests (53.9%); time-kill assays were applied in 12 studies, which encompass 359 tests (17.8%); gradient diffusion methods were used in seven studies, encompassing 293 tests (14.5%). And, finally, time-kill plus checkerboard were applied in two studies, encompassing 278 tests (13.8%). By comparing these data, checkerboard and time-kill methods were significantly more used than gradient diffusion methods (ptests (20.9%) with a synergistic effect; time-kill assays yielded 222 tests (61.8%) with a synergistic effect; gradient diffusion methods only provided 29 tests (9.9%) with a synergistic effect; and, finally, time-kill plus checkerboard yielded just 15 tests (5.4%) with a synergistic effect. When comparing these percentages, synergy rates reported by time-kill methods were significantly higher than that obtained by checkerboard and gradient diffusion methods (pplus Tigecycline, Vancomycin or Teicoplanin are not recommended. The best combinations of antibiotics are those which include bactericidal antibiotics such as Carbapenems, Fosfomycin, Amikacin, Polymyxins, Rifampicin and Ampicillin/Sulbactam. PMID:26415528

  18. Infections caused by Acinetobacter baumannii in recipients of hematopoietic stem cell transplantation

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    Khalid Ahmed Al-Anazi

    2014-07-01

    Full Text Available Acinetobacter baumannii (A. baumannii is a Gram-negative, strictly aerobic, non-fermentative coccobacillus which is widely distributed in nature. Recently, it has emerged as a major cause of health care-associated infections in addition to its capacity to cause community acquired infections. Risk factors for A. baumannii infections and bacteremia in recipients of hematopoietic stem cell transplantation include: severe underlying illness such as hematological malignancy, prolonged use of broad-spectrum antibiotics, invasive instrumentation such as central venous catheters or endotracheal intubation, colonization of respiratory, gastrointestinal or urinary tracts in addition to severe immunosuppression caused by using corticosteroids for treating graft versus host disease. The organism causes a wide spectrum of clinical manifestations, but serious complications such as bacteremia, septic shock, ventilator-associated pneumonia, extensive soft tissue necrosis and rapidly progressive systemic infections that ultimately lead to multiorgan failure and death are prone to occur in severely immunocompromised hosts. The organism is usually resistant to many antimicrobials including penicillins, cephalosporins, trimethoprim-sulfamethoxazole, almost all flouroquinolones and most of the aminoglycosides. The recently increasing resistance to carbapenems, colistin and polymyxins is alarming. Additionally, there are geographic variations in the resistance patterns and several globally and regionally resistant strains have already been described. Successful management of A.baumannii infections depends upon appropriate utilization of antibiotics and strict application of preventive and infection control measures. In uncomplicated infections, the use of a single active beta-lactam may be justified, while definitive treatment of complicated infections in critically ill individuals may require drug combinations such as colistin and rifampicin or colistin and

  19. Diversity of multi-drug resistant Acinetobacter baumannii population in a major hospital in Kuwait

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    Leila eVali

    2015-07-01

    Full Text Available Acinetobacter baumannii is one of the most important opportunistic pathogens that causes serious health care associated complications in critically ill patients. In the current study we report on the diversity of the clinical multi-drug resistant A. baumannii in Kuwait by molecular characterization. One hundred A. baumannii were isolated from one of the largest governmental hospitals in Kuwait. Following the identification of the isolates by molecular methods, the amplified blaOXA-51-like gene product of one isolate (KO-12 recovered from blood showed the insertion of the ISAba19 at position 379 in blaOXA-78. Of the 33 multi-drug resistant isolates, 28 (85% contained blaOXA-23, 2 (6% blaOXA-24 and 6 (18% blaPER-1 gene. We did not detect blaOXA-58, blaVIM, blaIMP, blaGES, blaVEB and blaNDM genes in any of the tested isolates. In 3 blaPER-1 positive isolates the genetic environment of blaPER-1 consisted of two copies of ISPa12 (tnpiA1 surrounding the blaPER-1 gene on a highly stable plasmid of ca. 140-kb. MLST analysis of the 33 A. baumannii isolates identified 20 different STs, of which 6 (ST-607, ST-608, ST-609, ST-610, ST-611 and ST-612 were novel. Emerging STs such as ST15 (identified for the first time in the Middle East, ST78 and ST25 were also detected. The predominant clonal complex was CC2. PFGE and MLST defined the MDR isolates as multi-clonal with diverse lineages. Our results lead us to believe that A. baumannii is diverse in clonal origins and / or is undergoing clonal expansion continuously while multiple lineages of MDR A. baumannii circulate in hospital wards simultaneously.

  20. In Vitro Activity and In Vivo Efficacy of Clavulanic Acid against Acinetobacter baumannii▿

    Science.gov (United States)

    Beceiro, Alejandro; López-Rojas, Rafael; Domínguez-Herrera, Juan; Docobo-Pérez, Fernando; Bou, Germán; Pachón, Jerónimo

    2009-01-01

    Clavulanic acid (CLA) exhibits low MICs against some Acinetobacter baumannii strains. The present study evaluates the efficacy of CLA in a murine model of A. baumannii pneumonia. For this purpose, two clinical strains, Ab11 and Ab51, were used; CLA MICs for these strains were 2 and 4 mg/liter, respectively, and the imipenem (IPM) MIC was 0.5 mg/liter for both. A pneumonia model in C57BL/6 mice was used. The CLA dosage (13 mg/kg of body weight given intraperitoneally) was chosen to reach a maximum concentration of the drug in serum similar to that in humans and a time during which the serum CLA concentration remained above the MIC equivalent to 40% of the interval between doses. Six groups (n = 15) were inoculated with Ab11 or Ab51 and were allocated to IPM or CLA therapy or to the untreated control group. In time-kill experiments, CLA was bactericidal only against Ab11 whereas IPM was bactericidal against both strains. CLA and IPM both decreased bacterial concentrations in lungs, 1.78 and 2.47 log10 CFU/g (P ≤ 0.001), respectively, in the experiments with Ab11 and 2.42 and 2.28 log10 CFU/g (P ≤ 0.001), respectively, with Ab51. IPM significantly increased the sterility of blood cultures over that for the controls with both strains (P ≤ 0.005); CLA had the same effect with Ab51 (P < 0.005) but not with Ab11 (P = 0.07). For the first time, we suggest that CLA may be used for the treatment of experimental severe A. baumannii infections. PMID:19635957

  1. Detection and typing of integrons in epidemic strains of Acinetobacter baumannii found in the United Kingdom.

    Science.gov (United States)

    Turton, Jane F; Kaufmann, Mary E; Glover, Judith; Coelho, Juliana M; Warner, Marina; Pike, Rachel; Pitt, Tyrone L

    2005-07-01

    Integrons were sought in Acinetobacter isolates from hospitals in the United Kingdom by integrase gene PCR. Isolates were compared by pulsed-field gel electrophoresis, and most belonged to a small number of outbreak strains or clones of A. baumannii, which are highly successful in the United Kingdom. Class 1 integrons were found in all of the outbreak isolates but in none of the sporadic isolates. No class 2 integrons were found. Three integrons were identified among the main outbreak strains and clones. While a particular integron was usually associated with a strain or clone, some members carried a different integron. Some integrons were associated with more than one strain. The cassette arrays of two of the integrons were very similar, both containing gene aacC1, which confers resistance to gentamicin, two open reading frames coding for unknown products (orfX, orfX'), and gene aadA1a, which confers resistance to spectinomycin and streptomycin. The larger of these integrons had two copies of the first (orfX) of the gene cassettes coding for unknown products. The third integron, with a cassette array containing gene aacA4, which codes for amikacin, netilmicin, and tobramycin resistance; a chloramphenicol acetyltransferase, catB8; and gene aadA1, conferring resistance to spectinomycin and streptomycin, was associated with an OXA-23 carbapenemase-producing clone, which has spread rapidly in hospitals in the United Kingdom during 2003 and 2004. These integron cassette arrays have been found in other outbreak strains of A. baumannii from other countries. We conclude that integrons are useful markers for epidemic strains of A. baumannii and that integron typing provides valuable information for epidemiological studies.

  2. 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.

  3. CRISPR-cas subtype I-Fb in Acinetobacter baumannii: evolution and utilization for strain subtyping.

    Science.gov (United States)

    Karah, Nabil; Samuelsen, Ørjan; Zarrilli, Raffaele; Sahl, Jason W; Wai, Sun Nyunt; Uhlin, Bernt Eric

    2015-01-01

    Clustered regularly interspaced short palindromic repeats (CRISPR) are polymorphic elements found in the genome of some or all strains of particular bacterial species, providing them with a system of acquired immunity against invading bacteriophages and plasmids. Two CRISPR-Cas systems have been identified in Acinetobacter baumannii, an opportunistic pathogen with a remarkable capacity for clonal dissemination. In this study, we investigated the mode of evolution and diversity of spacers of the CRISPR-cas subtype I-Fb locus in a global collection of 76 isolates of A. baumannii obtained from 14 countries and 4 continents. The locus has basically evolved from a common ancestor following two main lineages and several pathways of vertical descent. However, this vertical passage has been interrupted by occasional events of horizontal transfer of the whole locus between distinct isolates. The isolates were assigned into 40 CRISPR-based sequence types (CST). CST1 and CST23-24 comprised 18 and 9 isolates, representing two main sub-clones of international clones CC1 and CC25, respectively. Epidemiological data showed that some of the CST1 isolates were acquired or imported from Iraq, where it has probably been endemic for more than one decade and occasionally been able to spread to USA, Canada, and Europe. CST23-24 has shown a remarkable ability to cause national outbreaks of infections in Sweden, Argentina, UAE, and USA. The three isolates of CST19 were independently imported from Thailand to Sweden and Norway, raising a concern about the prevalence of CST19 in Thailand. Our study highlights the dynamic nature of the CRISPR-cas subtype I-Fb locus in A. baumannii, and demonstrates the possibility of using a CRISPR-based approach for subtyping a significant part of the global population of A. baumannii.

  4. Comparative proteomics of inner membrane fraction from carbapenem-resistant Acinetobacter baumannii with a reference strain.

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    Vishvanath Tiwari

    Full Text Available Acinetobacter baumannii has been identified by the Infectious Diseases Society of America as one of the six pathogens that cause majority of hospital infections. Increased resistance of A.baumannii even to the latest generation of β-lactams like carbapenem is an immediate threat to mankind. As inner-membrane fraction plays a significant role in survival of A.baumannii, we investigated the inner-membrane fraction proteome of carbapenem-resistant strain of A.baumannii using Differential In-Gel Electrophoresis (DIGE followed by DeCyder, Progenesis and LC-MS/MS analysis. We identified 19 over-expressed and 4 down-regulated proteins (fold change>2, p<0.05 in resistant strain as compared to reference strain. Some of the upregulated proteins in resistant strain and their association with carbapenem resistance in A.baumannii are: i β-lactamases, AmpC and OXA-51: cleave and inactivate carbapenem ii metabolic enzymes, ATP synthase, malate dehydrogenase and 2-oxoglutarate dehydrogenase: help in increased energy production for the survival and iii elongation factor Tu and ribosomal proteins: help in the overall protein production. Further, entry of carbapenem perhaps is limited by controlled production of OmpW and low levels of surface antigen help to evade host defence mechanism in developing resistance in A.baumannii. Present results support a model for the importance of proteins of inner-membrane fraction and their synergistic effect in the mediation of resistance of A.baumannii to carbapenem.

  5. CRISPR-cas subtype I-Fb in Acinetobacter baumannii: evolution and utilization for strain subtyping.

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    Nabil Karah

    Full Text Available Clustered regularly interspaced short palindromic repeats (CRISPR are polymorphic elements found in the genome of some or all strains of particular bacterial species, providing them with a system of acquired immunity against invading bacteriophages and plasmids. Two CRISPR-Cas systems have been identified in Acinetobacter baumannii, an opportunistic pathogen with a remarkable capacity for clonal dissemination. In this study, we investigated the mode of evolution and diversity of spacers of the CRISPR-cas subtype I-Fb locus in a global collection of 76 isolates of A. baumannii obtained from 14 countries and 4 continents. The locus has basically evolved from a common ancestor following two main lineages and several pathways of vertical descent. However, this vertical passage has been interrupted by occasional events of horizontal transfer of the whole locus between distinct isolates. The isolates were assigned into 40 CRISPR-based sequence types (CST. CST1 and CST23-24 comprised 18 and 9 isolates, representing two main sub-clones of international clones CC1 and CC25, respectively. Epidemiological data showed that some of the CST1 isolates were acquired or imported from Iraq, where it has probably been endemic for more than one decade and occasionally been able to spread to USA, Canada, and Europe. CST23-24 has shown a remarkable ability to cause national outbreaks of infections in Sweden, Argentina, UAE, and USA. The three isolates of CST19 were independently imported from Thailand to Sweden and Norway, raising a concern about the prevalence of CST19 in Thailand. Our study highlights the dynamic nature of the CRISPR-cas subtype I-Fb locus in A. baumannii, and demonstrates the possibility of using a CRISPR-based approach for subtyping a significant part of the global population of A. baumannii.

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

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    Liliana Ramírez- Moreno; Roxana Olvera-Ramírez

    2006-01-01

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

  7. 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.

  8. Prevalence of antibiotic-resistant Acinetobacter baumannii in a 1000-bed tertiary care hospital in Tehran, Iran

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    Rahbar Mohammad

    2010-04-01

    Full Text Available Acinetobacter baumannii is a ubiquitous pathogen that has emerged as a major cause of healthcare-associated infections. Acinetobacter baumannii usually causes respiratory tract, urinary tract, blood stream and surgical site infections. They are of increasing importance because of its ability to rapidly develop resistance to the major groups of antibiotics. There are few data available on the antimicrobial susceptibility of A. baumannii in Iran. During the period of study from July 2005 to November 2006, a total of 88 strains of A. baumannii were isolated from clinical specimens obtained from patients hospitalized in an Iranian 1000-bed tertiary care hospital. Conventional bacteriological methods were used for identification of A. baumannii. Susceptibility testing was performed by the method recommended by Clinical Laboratory and Standards Institute (CLSI. The majority of isolates were from respiratory tract specimens. The organism showed high rate of resistance to ceftriaxone (90.9%, piperacillin (90.9%, ceftazidime (84.1%, amikacin (85.2% and ciprofloxacin (90.9%. Imipenem was the most effective antibiotic against A. baumannii and the rate of resistance for imipenem was 4.5%. The second most effective antibiotic was tobramycin, and 44.3% of A. baumannii isolates were resistant to this antibiotic. In conclusion, our study showed that the rate of resistance in A. baumannii to imipenem was low. There was a significant relationship between demographic features of patients such as age, undergoing mechanical ventilation, length of hospital stay and drug resistance.

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

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    Noha Salah Elsayed

    2016-06-01

    Full Text Available Being biodegradable and biocompatible natural polymer, poly-β-hydroxybutyrate (PHB drew the attention of scientists to substitute synthetic plastics in our daily lives. However, its industrial production is hampered by its high cost. In this study, an extensive screening program was done to isolate bacteria with high PHB productivity from agricultural fields and develop a cost-effective PHB production. A promising bacterial isolate Acinetobacter baumannii P39 was recovered and identified using 16S ribosomal gene sequencing. It produced 24% PHB per dry weight after 48 h. Several experiments were conducted to optimize the composition of the culture medium and environmental factors for the selected isolate. Results revealed that 60% aeration, 28°C incubation temperature and initial pH 7.5 showed the highest productivity. Besides, 0.7% corn oil and 0.1 g/L peptone were the best carbon and nitrogen sources, respectively. Substituting glucose with corn oil led to a 23% reduction in total input cost and an estimate price for 1kg PHB is 20.5 L.E. Strain improvement by UV mutation succeeded in improving PHB production by two fold in the selected mutant P39M2. Finally, this study valorizes usage of Acinetobacter isolate in PHB production in addition to solving the critical problem of high cost of production.

  10. Drug Resistance of Acinetobacter Baumannii%鲍曼不动杆菌的耐药情况

    Institute of Scientific and Technical Information of China (English)

    唐希才; 郭亚云; 郭旭光; 夏勇; 江镜全

    2011-01-01

    [Objective] To understand the clinical distribution and the resistance of acinetobacter baumanii to in order to antibiotics, and provide evidence for the clinical therapeutics. [Methods]The strains identification and drug resistance of Acinetobacter baumanii were detected by Walkaway automatic bacterium identifying and drug sensitivity analyzing systems, and the results were analyzed [Results] There were 85 specimens detected with Acinetobacter baumanii , including sputum, blood, urine, cerebrospinal fluid (CSF) and incisional secretion, etc. The main specimen was the sputum (72.94% ). The drug resistant rates to Cefoperazone / sul-bactam and imipenem was 11.76% and 30.59% respectively, and to other antibiotics were high. [ Conclusion ] Acinetobacter baumanii mainly causes lower respiratory tract infection, had a high drug resistance rate to most antibiotics, imipenem and sulbactam are the first choice to treat the infections caused by Acinetobacter baumanii. It is very important to select rational drugs according to the results of antibiotics susceptibility tests to control the infection effectively and delay the occurrence of bacteria resistance.%目的 了解鲍曼不动杆菌的临床分布及其对常用抗生素的耐药状况,为临床使用抗生素治疗提供依据。方法 用Walkaway自动化细菌鉴定及药敏分析系统对菌落进行鉴定并做药敏试验,对检出的鲍曼不动杆菌的药敏结果做一分析。结果 在检出鲍曼不动杆菌的标本中有痰液、血液、尿液、脑脊液、伤口分泌物等标本,共85份。其中主要为痰液,占所有标本的72.94%。在药敏结果中,鲍曼不动杆菌对头孢哌酮/舒巴坦(舒普深)耐药率为¨.76%、亚胺培南30.59%,对其他抗生素耐药性较高。结论 鲍曼不动杆菌主要引起下呼吸道感染,其敏感抗生素谱窄,舒普深、亚胺培南可作为治疗的首选药物,对常用抗生素的使用,临床应根据药物敏感

  11. Presence of high-risk clones of OXA-23-producing Acinetobacter baumannii (ST79) and SPM-1-producing Pseudomonas aeruginosa (ST277) in environmental water samples in Brazil.

    Science.gov (United States)

    Turano, Helena; Gomes, Fernando; Medeiros, Micheli; Oliveira, Silvane; Fontes, Lívia C; Sato, Maria I Z; Lincopan, Nilton

    2016-09-01

    This study reports the presence of hospital-associated high-risk lineages of OXA-23-producing ST79 Acinetobacter baumannii and SPM-1-producing ST277 Pseudomonas aeruginosa in urban rivers in Brazil. These findings indicate that urban rivers can act as reservoirs of clinically important multidrug-resistant bacteria, which constitute a potential risk to human and animal health. PMID:27342783

  12. Investigation and management of multidrug-resistant Acinetobacter baumannii spread in a French medical intensive care unit: one outbreak may hide another.

    Science.gov (United States)

    Bourigault, Céline; Corvec, Stéphane; Bretonnière, Cédric; Guillouzouic, Aurélie; Crémet, Lise; Marraillac, Julie; Juvin, Marie-Emmanuelle; Bemer, Pascale; Le Gallou, Florence; Reynaud, Alain; Boutoille, David; Villers, Daniel; Lepelletier, Didier

    2013-07-01

    An outbreak in a medical intensive care unit was due to an OXA-23-producing Acinetobacter baumannii strain imported from a repatriate hospitalized in Singapore. This outbreak revealed another multidrug resistant epidemic strain that had been present in the hospital for 2 years. Both outbreaks were controlled after 9 months of an extensive infection control program.

  13. The 1.7 angstrom crystal structure of the apo form of the soluble quinoprotein glucose dehydrogenase from Acinetobacter calcoaceticus reveals a novel internal conserved sequence repeat

    NARCIS (Netherlands)

    Oubrie, A; Rozeboom, HJ; Kalk, KH; Duine, JA; Dijkstra, BW

    1999-01-01

    The crystal structure of a dimeric apo form of the soluble quinoprotein glucose dehydrogenase (s-GDH) from Acinetobacter calcoaceticus has been solved by multiple isomorphous replacement followed by density modification, and was subsequently refined at 1.72 Angstrom resolution to a final crystallogr

  14. Draft Genome Sequence of a Multidrug-Resistant Klebsiella pneumoniae Carbapenemase-Producing Acinetobacter baumannii Sequence Type 2 Isolate from Puerto Rico.

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    Martínez, Teresa; Ropelewski, Alexander J; González-Mendez, Ricardo; Vázquez, Guillermo J; Robledo, Iraida E

    2016-01-01

    We report here the draft genome sequence of Acinetobacter baumannii strain M3AC14-8, sequence type 2 (ST2), carrying a chromosomally carried blaKPC-2 gene. The draft genome consists of a total length of 4.11 Mbp and a G+C content of 39.25%. PMID:27540056

  15. Amplification of a single-locus variable-number direct repeats with restriction fragment length polymorphism (DR-PCR/RFLP) for genetic typing of Acinetobacter baumannii strains.

    Science.gov (United States)

    Nowak-Zaleska, Alicja; Krawczyk, Beata; Kotłowski, Roman; Mikucka, Agnieszka; Gospodarek, Eugenia

    2008-01-01

    In search of an effective DNA typing technique for Acinetobacter baumannii strains for hospital epidemiology use, the performance and convenience of a new target sequence was evaluated. Using known genomic sequences of Acinetobacter baumannii strains AR 319754 and ATCC 17978, we developed single-locus variable-number direct-repeat analysis using polymerase chain reaction-restriction fragment length polymorphism (DR-PCR/RFLP) method. A total of 90 Acinetobacter baumannii strains isolated from patients of the Clinical Hospital in Bydgoszcz, Poland, were examined. Initially, all strains were typed using macrorestriction analysis of the chromosomal DNA by pulsed-field gel electrophoresis (REA-PFGE). Digestion of the chromosomal DNA with the ApaI endonuclease and separation of the fragments by PFGE revealed 21 unique types. Application of DR-PCR/RFLP resulted in recognition of 12 clusters. The results showed that the DR-PCR/RFLP method is less discriminatory than REA-PFGE, however, the novel genotyping method can be used as an alternative technique for generating DNA profiles in epidemiological studies of intra-species genetic relatedness of Acinetobacter baumannii strains.

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

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    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.

  17. GENERATION OF A PROTON MOTIVE FORCE BY THE EXCRETION OF METAL-PHOSPHATE IN THE POLYPHOSPHATE-ACCUMULATING ACINETOBACTER-JOHNSONII STRAIN 210A

    NARCIS (Netherlands)

    VANVEEN, HW; ABEE, T; KORTSTEE, GJJ; PEREIRA, H; KONINGS, WN; ZEHNDER, AJB

    1994-01-01

    The strictly aerobic, polyphosphate-accumulating Acinetobacter johnsonii strain 210A degrades its polyphosphate when oxidative phosphorylation is impaired. The endproducts of this degradation, divalent metal ions and inorganic phosphate, are excreted as a neutral metal-phosphate (MeHPO(4)) chelate v

  18. ENERGETICS OF ALANINE, LYSINE, AND PROLINE TRANSPORT IN CYTOPLASMIC MEMBRANES OF THE POLYPHOSPHATE-ACCUMULATING ACINETOBACTER-JOHNSONII STRAIN 210A

    NARCIS (Netherlands)

    VANVEEN, HW; ABEE, T; KLEEFSMAN, AWF; MELGERS, B; KORTSTEE, GJJ; KONINGS, WN; ZEHNDER, AJB

    1994-01-01

    Amino acid transport in right-side-out membrane vesicles of Acinetobacter johnsonii 210A was studied. L-Alanine, L-lysine, and L-proline were actively transported when a proton motive force of -76 mV tvas generated by the oxidation of glucose via the membrane-bound glucose dehydrogenase. Kinetic ana

  19. Comparison of Acinetobacter baumannii isolates from the United Kingdom and the United States that were associated with repatriated casualties of the Iraq conflict.

    Science.gov (United States)

    Turton, Jane F; Kaufmann, Mary E; Gill, Martin J; Pike, Rachel; Scott, Paul T; Fishbain, Joel; Craft, David; Deye, Gregory; Riddell, Scott; Lindler, Luther E; Pitt, Tyrone L

    2006-07-01

    Acinetobacter isolates associated with casualties from the Iraq conflict from the United States were compared with those from the United Kingdom by pulsed-field gel electrophoresis and integron analysis. Representatives of the main outbreak strain associated with casualties from both countries were indistinguishable in DNA profile. Two further outbreak strains were common to both sets of isolates.

  20. [Toxocara sp. eggs and Ancylostoma sp. larva in public parks, Brazil].

    Science.gov (United States)

    Guimarães, Antônio Marcos; Alves, Endrigo Gabellini Leonel; de Rezende, Glycia Ferreira; Rodrigues, Marcelo Costa

    2005-04-01

    Visceral and cutaneous larva migrans are parasitic zoonoses caused by the infection of larval nematodes Toxocara sp. and Ancylostoma sp. respectively. The objective of this study was to investigate the contamination by Toxocara sp. eggs and Ancylostoma sp. eggs and larva of soil samples collected from public parks and children's playground areas in state of Minas Gerais, Brazil, using both Baermann's method and centrifugal flotation technique. Toxocara sp. and Ancylostoma sp. eggs were observed in soil samples collected from public squares in 17.4% (4/23) and 69.6 (16/23) respectively. In schools and child day care settings the contamination by Ancylostoma sp. larva in sand samples was 11.1% (2/18). Public parks are settings of more potential risk of Toxocara sp. eggs and Ancylostoma sp. infection. Stool parasitology testing of 174 stool samples showed 58% and 23% of Ancylostoma sp and Toxocara sp eggs infection respectively.

  1. Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov. and Lactobacillus kullabergensis sp. nov., isolated from the honey stomach of the honeybee Apis mellifera.

    Science.gov (United States)

    Olofsson, Tobias C; Alsterfjord, Magnus; Nilson, Bo; Butler, Eile; Vásquez, Alejandra

    2014-09-01

    We previously discovered a symbiotic lactic acid bacterial (LAB) microbiota in the honey stomach of the honeybee Apis mellifera. The microbiota was composed of several phylotypes of Bifidobacterium and Lactobacillus. 16S rRNA gene sequence analyses and phenotypic and genetic characteristics revealed that the phylotypes isolated represent seven novel species. One grouped with Lactobacillus kunkeei and the others belong to the Lactobacillus buchneri and Lactobacillus delbrueckii subgroups of Lactobacillus. We propose the names Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov. and Lactobacillus kullabergensis sp. nov. for these novel species, with the respective type strains being Fhon13N(T) ( = DSM 26257(T) = CCUG 63287(T)), Bin4N(T) ( = DSM 26254(T) = CCUG 63291(T)), Hon2N(T) ( = DSM 26255(T) = CCUG 63289(T)), Hma8N(T) ( = DSM 26256(T) = CCUG 63629(T)), Hma2N(T) ( = DSM 26263(T) = CCUG 63633(T)), Bma5N(T) ( = DSM 26265(T) = CCUG 63301(T)) and Biut2N(T) ( = DSM 26262(T) = CCUG 63631(T)).

  2. Isolation and Characterization of a Virulent Bacteriophage AB1 of Acinetobacter baumannii

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    Jia Shiru

    2010-04-01

    Full Text Available Abstract Background Acinetobacter baumannii is an emerging nosocomial pathogen worldwide with increasing prevalence of multi-drug and pan-drug resistance. A. baumannii exists widely in natural environment, especially in health care settings, and has been shown difficult to be eradicated. Bacteriophages are often considered alternative agent for controlling bacterial infection and contamination. In this study, we described the isolation and characterization of one virulent bacteriophage AB1 capable of specifically infecting A. baumannii. Results A virulent bacteriophage AB1, specific for infecting a clinical strain A. baumannii KD311, was first isolated from marine sediment sample. Restriction analysis indicated that phage AB1 was a dsDNA virus with an approximate genome size of 45.2 kb to 46.9 kb. Transmission electron microscopy showed that phage AB1 had an icosahedral head with a non-contractile tail and collar or whisker structures, and might be tentatively classified as a member of the Siphoviridae family. Proteomic pattern of phage AB1, generated by SDS-PAGE using purified phage particles, revealed five major bands and six minor bands with molecular weight ranging from 14 to 80 kilo-dalton. Also determined was the adsorption rate of phage AB1 to the host bacterium, which was significantly enhanced by addition of 10 mM CaCl2. In a single step growth test, phage AB1 was shown having a latent period of 18 minutes and a burst size of 409. Moreover, pH and thermal stability of phage AB1 were also investigated. At the optimal pH 6.0, 73.2% of phages survived after 60 min incubation at 50°C. When phage AB1 was used to infect four additional clinical isolates of A. baumannii, one clinical isolate of Stenotrophomonas maltophilia, and Pseudomonas aeruginosa lab strains PAK and PAO1, none of the tested strains was found susceptible, indicating a relatively narrow host range for phage AB1. Conclusion Phage AB1 was capable of eliciting efficient lysis

  3. INHIBITION OF Acinetobacter baumannii ADHESION BY ANTI-FIMBRIAL ANTIBODY: THE FIMBRIAL ANTIGEN EFFECTIVENESS

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    Hadeel K. Musafer

    2013-01-01

    Full Text Available Collecting samples of Acinetobacter baumannii taken from different clinical cases of wounds, septicemia, and urinary tract infections. That was accomplished by taking (296 samples from Baghdad educational hospital and Ibn-al-Baladi hospital. Samples were cultured on solid media (McConkey and blood agars, and according to microscopical, cultural, and biochemical identification, in addition to using API 20-E system, (21 isolates of A. baumannii were identified and in percentage of 47.619, 9.523, 14.285, and 28.571 for wound, blood, sputum, and urine samples, respectively. Methods: detection of fimbriated bacterial isolates among 21 isolates, and all those isolated were fimbriae forming isolates; isolate number (9 was selected as an effective isolate in formation of fimbriae. Non-forming fimbriae isolate of Shigella flexneri is used as negative control. Results and Conclusion: the average of adherence of fimbriated bacterial cell with human epithelial cells was reached (50 adherent bacterial cell per epithelial cell compared with the average of adherence of control isolate (12 adherent bacterial cell per epithelial cell, the inhibition processes are performed: Inhibition of bacterial adherence by specific antibodies of fimbriae antigen showed inhibition effect of adherence in respect to fimbriated isolate A. baumannii 9 also the subminimum inhibitory concentration for four antibiotics (Gentamicin, Tobramycin, Cefepime, and Amikacin inhibit the adherence of fimbriated isolate. The isolates (used in the study have the ability to agglutinate Saccharomyces cerevisiae and human red blood corpuscles (RBCs. The study of effect of different fimbriae extract concentrations (25, 50, 100 μg/ml on immune cells; consequently, reached to the following results: Concentrations of (25, 50, 100 μg/ml showed a negative effect on lymphocyte and PMNs viability which increased significantly (P≤0.05 with increasing of fimbriae extract concentration. On the other hand

  4. Drug-resistant genes carried by Acinetobacter baumanii isolated from patients with lower respiratory tract infection

    Institute of Scientific and Technical Information of China (English)

    DAI Ning; ZHANG Wei; LI Jia-shu; YU Qin; WAN Huan-ying; MU Lan; ZHONG Xiao-ning; WEI Li-ping; MA Jian-jun; WANG Qiu-yue; HU Ke; LI De-zhi; TIAN Gui-zhen; CAI Shao-xi; WANG Rui-qin; HE Bei; WANG Si-qin; WANG Zhan-wei; ZHAO Su-rui; GAO Zhan-cheng; CHEN Ji-chao; CHEN Yu-sheng; GENG Rong; HU Ying-hui; YANG Jing-ping; DU Juan; HU Cheng-ping

    2010-01-01

    Background Acinetobacter baumanii (A. baumanii) remains an important microbial pathogen resulting in nosocomial acquired infections with significant morbidity and mortality. The mechanism by which nosocomial bacteria, like A.baumanii, attain multidrug resistance to antibiotics is of considerable interest. The aim in this study was to investigate the spread status of antibiotic resistance genes, such as multiple β-lactamase genes and aminoglycoside-modifying enzyme genes, from A. baumanii strains isolated from patients with lower respiratory tract infections (LRTIs).Methods Two thousand six hundred and ninety-eight sputum or the bronchoalveolar lavage samples from inpatients with LRTIs were collected in 21 hospitals in the mainland of China from November 2007 to February 2009. All samples were routinely inoculated. The isolated bacterial strains and their susceptibility were analyzed via VITEK-2 expert system.Several kinds of antibiotic resistant genes were further differentiated via polymerase chain reaction and sequencing methods.Results Totally, 39 A. baumanii strains were isolated from 2698 sputum or bronchoalveolar lavage samples. There was not only a high resistant rate of the isolated A. baumanii strains to ampicillin and first- and second-generation cephalosporins (94.87%, 100% and 97.44%, respectively), but also to the third-generation cephalosporins (ceftriaxone at 92.31%, ceftazidine at 51.28%) and imipenem (43.59%) as well. The lowest antibiotic resistance rate of 20.51% was found to amikacin. The OXA-23 gene was identified in 17 strains of A. baumanii, and the AmpC gene in 23 strains. The TEM-1 gene was carried in 15 strains. PER-1 and SHV-2 genes were detected in two different strains.Aminoglycoside-modifying enzyme gene aac-3-la was found in 23 strains, and the aac-6'-lb gene in 19 strains, aac-3-la and aac-6'-lb genes hibernated in three A. baumanii strains that showed no drug-resistant phenotype.Conclusions A. baumaniican carry multiple drug

  5. Adjuvant role of Pseudomonas flagellin for Acinetobacter baumannii biofilm associated protein

    Science.gov (United States)

    Sefidi, Mozhgan Derakhshan; Rasooli, Iraj; Owlia, Parviz; Talei, Daryush; Astaneh, Shakiba Darvish Alipour; Nazarian, Shahram

    2016-01-01

    AIM To study immunogenicity of Pseudomonas N terminal flagellin as an adjuvant for Acinetobacter baumannii (A. baumannii) biofilm associated protein (Bap). METHODS The N terminal flagellin gene was amplified. The pET28a (+) and polymerase chain reaction products were digested with HindIII and EcoR I. The ligation of N terminal flagellin into pET28a (‏+) was performed using T4 DNA ligase and was then transformed into Escherichia coli BL21 (DE3) as a suitable expression host. pET28a (‏+) vector harboring a conserved region of Bap from our previous work was used. The recombinant proteins were expressed, analyzed by SDS-PAGE method and was purified by affinity chromatography with His-Tag residues followed by confirmation with western blotting. Mice were immunized with recombinant N terminal flagellin and Bap subunits. The immunized animals were intranasally (i.n) challenged with A. baumannii and Pseudomonas aeruginosa (P. aeruginosa). RESULTS The flagellin enhanced the immunogenicity of Bap causing an increase in specific IgG titers in serum (P Bap-Flagellin immunized group challenged with A. baumannii showed significantly lower bacterial load compared to the control group. The bacterial loads were studied in internal organs. A. baumannii infected immunized animals with Bap-Flagellin exhibited internal organs with minor bacterial load while P. aeruginosa PAO1 infected group showed heavy bacterial load of (4.3 ± 0.12) × 106, (1.1 ± 0.01) × 106 and (2.2 ± 0.22) × 106 per gram of lungs, liver and spleen respectively. Bacterial loads were detected per gram of lungs, liver and spleen of the mice group immunized with Bap were (1.2 ± 0.06) × 107, (11.1 ± 0.041) × 105 and (3.6 ± 0.42) × 106 respectively. In vivo neutralization assay indicated that all experimental mice groups, except for Flagellin administered group was significantly (P < 0.05) protected against A. baumannii. CONCLUSION These results demonstrate that P. aeruginosa Flagellin as an adjuvant for

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

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    Aynur Camkıran

    2011-08-01

    Full Text Available Objective: Multidrug resistant Acinetobacter baumannii (MRAB is an important cause of hospital acquired infection and leads to an increasing morbidity and mortality in intensive care units (ICU. The aim of this study was to investigate the predictors of MRAB infection in surgical ICU patients. Material and Method: The charts of the patients who were admitted to the ICU between January 2008 and August 2010 were reviewed to identify patients with MRAB infection. Recorded data were as follows: age, sex, medical history, underlying surgical pathology, Acute Physiology and Chronic Health Evaluation II score (APACHE II and Glasgow Coma Score on ICU admission,presence of invasive procedures (intubation, arterial, central venous lines, urinary catheters, and renal replacement therapy, days in ICU and white blood cells (WBC and lactate count on infection day, infection site, complications (such as organ/system failure, length of stay (LOS in the ICU and hospital, and final outcome. Results: During the study period 25 patients with MRAB infection were identified. When compared with their matched control group (n=25, patients with MRAB infection had a significantly higher mean APACHE II score (p=0.001 and more frequently had an open wound (p=0.002 or required mechanical ventilation (p=0.005, with respiratory system disease (p=0.03, arterial catheterization (p=0.006, and central venous catheterization (p=0.004. Multivariate logistic regression revealed that APACHE II score (OR,1.155; CI, 1.008-1.324; p= 0.038 and open wound (OR, 27.77; CI, 2.020-333.333; p=0.018 were predictors of MRAB infection in these patients. Compared to their controls, patients with MRAB infection hand a longer LOS in ICU (36.44±30.44 days vs 7.80±8.13 days, p<0.000 and hospital (55.12±40.81 days vs 19.04±13.44 days, p<0.000. In hospital mortality rates for patients with MRAB infection and their controls were 56% and 32%, respectively (p=0.154. Conclusion: Our results indicate

  7. The influence of carbapenem resistance on mortality in solid organ transplant recipients with Acinetobacter baumannii infection

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    de Gouvêa Erika

    2012-12-01

    Full Text Available Abstract Background Infection with carbapenem-resistant Acinetobacter baumannii has been associated with high morbidity and mortality in solid organ transplant recipients. The main objective of this study was to assess the influence of carbapenem resistance and other potential risk factors on the outcome of A. baumannii infection after kidney and liver transplantation. Methods Retrospective study of a case series of A. baumannii infection among liver and renal transplant recipients. The primary outcome was death associated with A. baumannii infection. Multivariate logistic regression was used to assess the influence of carbapenem resistance and other covariates on the outcome. Results Forty-nine cases of A. baumannii infection affecting 24 kidney and 25 liver transplant recipients were studied. Eighteen cases (37% were caused by carbapenem-resistant isolates. There were 17 (35% deaths associated with A. baumannii infection. In unadjusted analysis, liver transplantation (p = 0.003, acquisition in intensive care unit (p = 0.001, extra-urinary site of infection (p A. baumannii infection. The number of deaths associated with A. baumannii infection was higher among patients infected with carbapenem-resistant isolates, but the difference was not significant (p = 0.28. In multivariate analysis, the risk of A. baumannii-associated mortality was higher in patients with infection acquired in the intensive care unit (odds ratio [OR] = 34.8, p = 0.01 and on mechanical ventilation (OR = 15.2, p = 0.04. Appropriate empiric antimicrobial therapy was associated with significantly lower mortality (OR = 0.04, p = 0.03, but carbapenem resistance had no impact on it (OR = 0.73, p = 0.70. Conclusion These findings suggest that A. baumannii-associated mortality among liver and kidney transplant recipients is influenced by baseline clinical severity and by the early start of appropriate therapy, but not by carbapenem

  8. Surveillance of multidrug resistance-associated genes in Acinetobacter baumannii isolates from elderly patients

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    Zhe DONG

    2012-03-01

    Full Text Available Objective To understand the status of multidrug resistance-associated genes carried by Acinetobacter baumannii isolates from elderly patients in our hospital in order to provide a basis for surveillance of drug-resistance and inflection control. Methods One hundred and twenty A. baumannii isolates were collected from elderly patients between 2008 and 2010. The mean age of the patients was 85 (65 to 95 years. Whonet 5.6 software was used to analyze the resistance rate of 16 antimicrobial agents. Polymerase chain reaction (PCR and the sequencing method were adopted to detect 10 kinds of resistance genes (blaOXA-51-like, blaOXA- 23-like, blaOXA-24-like, blaOXA-58-like, blaTEM, blaampC, armA, ISAba1, intI 1, and intI 2. The corresponding resistance gene profiling(RGP was analyzed and designated according to the status of resistance genes. Results The resistance rates to the remaining 15 kinds of antibiotics varied between 70.8% and 97.5%, with the exception of the sensitivity rate to polymyxin B by up to more than 90%. The positivity rates of blaOXA-51-like, blaOXA-23-like, blaOXA-58-like, blaTEM, blaampC, armA, ISAba1 and intI 1 were 100%, 81.7%, 0.8%, 10.8%, 91.7%, 81.7%, 86.7%, and 83.3% respectively. A total of 18 kinds of drug-resistant gene maps were found, but blaOXA-24-like and intI 2 were not detected. Among these gene maps, the rate of RGP1 (blaOXA-23-like+blaampC+armA+ISAba1+ intI 1 was as high as 60.8%. Conclusions A. baumannii isolates from elderly patients have a higher carrying rate of drug-resistant genes, resulting in severe multidrugresistant conditions. Therefore, full-time infection control personnel and clinical physicians should actively participate in the surveillance, prevention, and control of infections caused by A. baumannii in the elderly.

  9. Multiple drug resistant carbapenemases producing Acinetobacter baumannii isolates harbours multiple R-plasmids

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    Rajagopalan Saranathan

    2014-01-01

    Full Text Available Background & objectives: The nosocomial human pathogen Acinetobacter baumannii has high propensity to develop resistance to antimicrobials and to become multidrug resistant (MDR, consequently complicating the treatment. This study was carried out to investigate the presence of resistant plasmids (R-plasmids among the clinical isolates of A. baumannii. In addition, the study was performed to check the presence of common β-lactamases encoding genes on these plasmids. Methods: A total of 55 clinical isolates of A. baumannii were included in the study and all were subjected to plasmid DNA isolation, followed by PCR to check the presence of resistance gene determinants such as blaOXA-23 , blaOXA-51, blaOXA-58 and blaIMP-1 on these plasmids that encode for oxacillinase (OXA and metallo-β-lactamase (MBL type of carbapenemases. Plasmid curing experiments were carried out on selected isolates using ethidium bromide and acridine orange as curing agents and the antibiotic resistance profiles were evaluated before and after curing. Results: All the isolates were identified as A. baumannii by 16SrDNA amplification and sequencing. Plasmid DNA isolated from these isolates showed the occurrence of multiple plasmids with size ranging from 500bp to ≥ 25 kb. The percentage of blaOXA-51 and blaOXA-23 on plasmids were found to be 78 and 42 per cent, respectively and 20 isolates (36% carried blaIMP-1 gene on plasmids. Significant difference was observed in the antibiograms of plasmid cured isolates when compared to their parental ones. The clinical isolates became susceptible to more than two antibiotic classes after curing of plasmids indicating plasmid borne resistance. Interpretation & conclusions: Our study determined the plasmid mediated resistance mechanisms and occurrence of different resistance genes on various plasmids isolated from MDR A. baumannii. The present findings showed the evidence for antibiotic resistance mediated through multiple plasmids in

  10. Pantoea vagans sp. nov., Pantoea eucalypti sp. nov., Pantoea deleyi sp. nov. and Pantoea anthophila sp. nov.

    Science.gov (United States)

    Brady, Carrie L; Venter, Stephanus N; Cleenwerck, Ilse; Engelbeen, Katrien; Vancanneyt, Marc; Swings, Jean; Coutinho, Teresa A

    2009-09-01

    Bacteria isolated from eucalyptus leaves and shoots showing symptoms of blight and die-back collected in Uganda, Uruguay and Argentina and from maize displaying brown stalk rot symptoms in South Africa were tentatively placed in the genus Pantoea on the basis of phenotypic and biochemical tests. These isolates, together with two strains (LMG 2558 and LMG 2560) previously assigned to Pantoea agglomerans based on protein electrophoregrams but later excluded from this species, were further investigated using molecular techniques. 16S rRNA gene sequencing and multilocus sequence analyses (MLSA) revealed that the strains were phylogenetically closely related to Pantoea agglomerans, Pantoea stewartii and Pantoea ananatis. MLSA and amplified fragment length polymorphism analysis placed the strains into four separate clusters, not containing any of the type strains of species of the genus Pantoea. DNA-DNA hybridization confirmed the classification of the isolates into four novel species, for which the names Pantoea vagans sp. nov. (type strain R-21566T=LMG 24199T=BCC 105T=BD 765T), Pantoea eucalypti sp. nov. (type strain R-25678T=LMG 24197T=BCC 076T=BD 769T), Pantoea deleyi sp. nov. (type strain R-31523T=LMG 24200T=BCC 109T=BD 767T) and Pantoea anthophila sp. nov. (type strain LMG 2558T=BD 871T=NCPPB 1682T) are proposed. PMID:19620357

  11. 鲍曼不动杆菌临床分布和耐药性分析%Clinical Distribution and Drug Resistance of Acinetobacter baumanii

    Institute of Scientific and Technical Information of China (English)

    王厚照; 张玲; 尚碧莲; 孙光伟; 邸玥莹

    2011-01-01

    目的 了解临床标本中鲍曼不动杆菌的临床分布和耐药情况,为临床控制感染提供依据.方法 采用回顾性方法统计分析93株鲍曼不动杆菌的标本来源、感染科室分布及耐药状况.结果 鲍曼不动杆菌最常出现在痰液标本中;神经外科ICU病房鲍曼不动杆菌的检出率较高;鲍曼不动杆菌耐药现象比较严重,对多种抗生素耐药率均大于30%(除头孢哌酮/舒巴坦和亚胺培南).结论 鲍曼不动杆菌为多重耐药菌株,临床要重视合理使用抗菌药物,加强预防标准,控制其引发的院内感染.%Objective To investigate the clinical distribution and drug resistance of Acinetobacter baumanii in clinical specimens, and to provide the reference for control of nosocomial infections.Methods Sample sources, clinical distribution and drug resistance of 93 strains of Acinetobacter baumanii were retrospectively analyzed.Results Among the 93 specimens, the dominant specimen was the sputum.The detection rate of Acinetobacter baumanii in the ICU of Department of Neurosurgery was the highest.The drug resistant rates to most antibacterials were over 30% except SCF and imipenem.Conclusions Acinetobacter baumani was multi - drug resistant organism.Rational application of antibiotics and standard prevention should be strengthened to control the nosocomial infection caused by Acinetobacter baumani mainly.

  12. Proteogenomic Characterization of Monocyclic Aromatic Hydrocarbon Degradation Pathways in the Aniline-Degrading Bacterium Burkholderia sp. K24.

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    Sang-Yeop Lee

    Full Text Available Burkholderia sp. K24, formerly known as Acinetobacter lwoffii K24, is a soil bacterium capable of utilizing aniline as its sole carbon and nitrogen source. Genomic sequence analysis revealed that this bacterium possesses putative gene clusters for biodegradation of various monocyclic aromatic hydrocarbons (MAHs, including benzene, toluene, and xylene (BTX, as well as aniline. We verified the proposed MAH biodegradation pathways by dioxygenase activity assays, RT-PCR, and LC/MS-based quantitative proteomic analyses. This proteogenomic approach revealed four independent degradation pathways, all converging into the citric acid cycle. Aniline and p-hydroxybenzoate degradation pathways converged into the β-ketoadipate pathway. Benzoate and toluene were degraded through the benzoyl-CoA degradation pathway. The xylene isomers, i.e., o-, m-, and p-xylene, were degraded via the extradiol cleavage pathways. Salicylate was degraded through the gentisate degradation pathway. Our results show that Burkholderia sp. K24 possesses versatile biodegradation pathways, which may be employed for efficient bioremediation of aniline and BTX.

  13. An Sp1/Sp3 binding polymorphism confers methylation protection.

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    Yanis A Boumber

    Full Text Available Hundreds of genes show aberrant DNA hypermethylation in cancer, yet little is known about the causes of this hypermethylation. We identified RIL as a frequent methylation target in cancer. In search for factors that influence RIL hypermethylation, we found a 12-bp polymorphic sequence around its transcription start site that creates a long allele. Pyrosequencing of homozygous tumors revealed a 2.1-fold higher methylation for the short alleles (P<0.001. Bisulfite sequencing of cancers heterozygous for RIL showed that the short alleles are 3.1-fold more methylated than the long (P<0.001. The comparison of expression levels between unmethylated long and short EBV-transformed cell lines showed no difference in expression in vivo. Electrophorectic mobility shift assay showed that the inserted region of the long allele binds Sp1 and Sp3 transcription factors, a binding that is absent in the short allele. Transient transfection of RIL allele-specific transgenes showed no effects of the additional Sp1 site on transcription early on. However, stable transfection of methylation-seeded constructs showed gradually decreasing transcription levels from the short allele with eventual spreading of de novo methylation. In contrast, the long allele showed stable levels of expression over time as measured by luciferase and approximately 2-3-fold lower levels of methylation by bisulfite sequencing (P<0.001, suggesting that the polymorphic Sp1 site protects against time-dependent silencing. Our finding demonstrates that, in some genes, hypermethylation in cancer is dictated by protein-DNA interactions at the promoters and provides a novel mechanism by which genetic polymorphisms can influence an epigenetic state.

  14. Nickel biosorption by Acinetobacter baumannii and Pseudomonas aeruginosa isolated from industrial wastewater Bioadsorção de niquel por Acinetobacter baumannii e Pseudomonas aeruginosa isoladas de águas residuais industriais

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    Carlos E. Rodríguez

    2006-12-01

    Full Text Available Nickel biosorption ability was evaluated in two bacterial strains: Acinetobacter baumannii UCR-2971 and Pseudomonas aeruginosa UCR-2957, resulting in greatest adsorption at pH 4.5 and a residence time of 100 minutes. Biosorption isotherms showed that the process follows the Langmuir model. The maximum adsorption rates (Nmax were 8.8 and 5.7 mg·g-1 for A. baumannii and P. aeruginosa, respectively; however, affinity constants suggest that P. aeruginosa (K=1.28 has higher affinity for nickel than A. baumannii (K=0.68. It is suggested that both strains could be used for wastewater treatment, as long as the concentration of Ni2+ is within the range of mg·L-1.Foi avaliada a capacidade de adsorção do Ni2+ por duas bactérias, Acinetobacter baumannii e Pseudomonas aeruginosa, em pH 4.5 com tempo de contato de 100 minutos. Isotermas de adsorção foram calculadas com as duas linhagens. Observou-se que, para ambas, o processo de adsorção está de acordo com o modelo fisicoquímico de Langmuir. A captação máxima do Ni2+ (Nmax foi 5.7 e 8.8 mg Ni2+ g-1 para P. aeruginosa e A. baumannii, respectivamente. Não obstante, P. aeruginosa apresenta uma constante de afinidade (K=1.28 maior que A. baumannii (K=0.68. Estes resultados indicam que ambas as linhagens são adequadas para o tratamento de águas contaminadas, desde que a concentração de níquel seja da ordem de mg·L-1.

  15. 不动杆菌肺部感染诊治进展%Advances in diagnosis and treatment of pulmonary infection with Acinetobacter

    Institute of Scientific and Technical Information of China (English)

    施毅; 印洁

    2011-01-01

    Acinetobacter,especially Acinetobacter baumannii has emerged in recent years as a major cause of nosocomial infections, especially in intensive care units (ICUs),due to its multidrug-resistance (MDR) even pan-drug-resistance (PDR) characteristics.Acinetobacter infection may lead to high mortality, and it is serious and detrimental to patients. In the year 2009, CHINET antimicrobial surveillance showed that lung was the most commonly infected organ, and SENTRY antimicrobial surveillance showed that Acinetobacter had become the top fifth cause of hospital-acquired pneumonia (HAP), and its antibiotic resistance had gradually increased in these years. Colonization or infection of Acinetobacter should be determined at once when the bacteria were detected from culture of respiratory secretions. Generally, antibacterial treatment is not recommended if no clinical symptoms appear or imaging evidence unavailable. Since the resistance rate of Acinetobacter baumannii to most of the antibiotics reached 50% and above, an effective antibiotics should be carefully selected based on susceptibility test. Sulbactam or sulbactam-based composition is recommended for the carbapenem-resistant bacteria infection, particularly for infections caused by pan-resistant strains. As the first glycylcycline was approved to use in clinic, the anti-bacterial activity of Tigecycline against anti-carbapenem-resistant Acinetobacter has already been proven in vitro. In addition, the most important measure in controlling Acinetobacter pneumonia is to prevent the outbreak of Acinetobacter in medical institutions.%近年来,不动杆菌尤其是鲍曼不动杆菌已成为院内感染的常见病原菌,并呈现多重耐药甚至泛耐药趋势.不动杆菌感染病死率高、危害严重.2009年中国细菌耐药监测网(CHINET)的数据显示,不动杆菌最常见的感染部位为肺部,全球细菌耐药监测数据(SENTRY)显示,不动杆菌居医院获得性肺炎(HAP)常见致病原的第5位.

  16. Draft genome sequence of a multidrug-resistant blaOXA-23-producing Acinetobacter baumannii ST208 isolate from China.

    Science.gov (United States)

    Chen, Yan; Wu, Liyan; Chen, Yu; Xu, Zhijun; Xu, Liqun

    2016-03-01

    Acinetobacter baumannii has emerged worldwide as an important opportunistic nosocomial pathogen and has become a major public health concern. In this study, the draft genome sequence of A. baumannii TCM331 (ST208/CC92), a multidrug-resistant (MDR) isolate harbouring the blaOXA-23 gene isolated in China, was determined. The genome of TCM331 was sequenced via Illumina HiSeq™ 2000, and bioinformatics analysis was performed. Important antimicrobial resistance determinants were observed in an estimated genome size of 4,058,691bp with 3838 predicted coding regions. In conclusion, these data might facilitate further understanding of the specific genomic features of MDR A. baumannii in China. PMID:27436391

  17. Purification and partial characterization of lignin peroxidase from Acinetobacter calcoaceticus NCIM 2890 and its application in decolorization of textile dyes.

    Science.gov (United States)

    Ghodake, Gajanan S; Kalme, Satish D; Jadhav, Jyoti P; Govindwar, Sanjay P

    2009-01-01

    Lignin peroxidase was purified (72-fold) from Acinetobacter calcoaceticus NCIM 2890. The purified lignin peroxidase (55-65 kDa) showed dimeric nature. The maximum enzyme activity was observed at pH 1.0, between a broad temperature range of 50 and 70 degrees C, at H2O2 concentration (40 mM) and the substrate concentration (n-propanol, 100 mM). Purified lignin peroxidase was able to oxidize a variety of substrates including Mn2+, tryptophan, mimosine, L-Dopa, hydroquinone, xylidine, n-propanol, veratryl alcohol, and ten textile dyes of various groups indicating as a versatile peroxidase. Most of the dyes decolorized up to 90%. Tryptophan stabilizes the lignin peroxidase activity during decolorization of dyes.

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

    Science.gov (United States)

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

    2011-10-01

    Acinetobacter calcoaceticus NCIM 2890 (A. caloaceticus) was found to decolorize 20 different textile dyes of various classes. Decolorization of an azo dye amaranth was observed effectively (91%) at static anoxic condition, whereas agitated culture grew well but showed less decolorization (68%) within 48 h of incubation. Induction of intracellular and extracellular lignin peroxidase, intracellular laccase, dichlorophenol indophenol (DCIP) reductase and riboflavin reductase represented their involvement in the biodegradation of amaranth. The products obtained after degradation of Amaranth were characterized as naphthalene sulfamide, hydroxyl naphthalene diazonium and naphthalene diazonium. The germination and growth of Sorghum vulgare and Phaseolus mungo seeds, and the growth of E. coli and Bacillus substilis were not inhibited by the metabolic products of the dye.

  19. Clinical validation of a real-time polymerase chain reaction assay for rapid detection of Acinetobacter baumannii colonization.

    Science.gov (United States)

    Blanco-Lobo, P; González-Galán, V; García-Quintanilla, M; Valencia, R; Cazalla, A; Martín, C; Alonso, I; Pérez-Romero, P; Cisneros, J M; Aznar, J; McConnell, M J

    2016-09-01

    Real-time polymerase chain reaction (PCR)-based approaches have not been assessed in terms of their ability to detect patients colonized by Acinetobacter baumannii during active surveillance. This prospective, double-blind study demonstrated that a real-time PCR assay had high sensitivity (100%) and specificity (91.2%) compared with conventional culture for detecting A. baumannii in 397 active surveillance samples, and provided results within 3h. Receiver-operator curve analyses demonstrated that the technique has diagnostic accuracy of 97.7% (95% confidence interval 96.0-99.3%). This method could facilitate the rapid implementation of infection control measures for preventing the transmission of A. baumannii. PMID:27206968

  20. Plant growth-promoting and rhizosphere-competent Acinetobacter rhizosphaerae strain BIHB 723 from the cold deserts of the Himalayas.

    Science.gov (United States)

    Gulati, Arvind; Vyas, Pratibha; Rahi, Praveen; Kasana, Ramesh Chand

    2009-04-01

    A phosphate-solubilizing bacterial strain BIHB 723 isolated from the rhizosphere of Hippophae rhamnoides was identified as Acinetobacter rhizosphaerae on the basis of phenotypic characteristics, carbon source utilization pattern, fatty acid methyl esters analysis, and 16S rRNA gene sequence. The strain exhibited the plant growth-promoting attributes of inorganic and organic phosphate solubilization, auxin production, 1-aminocyclopropane-1-carboxylate deaminase activity, ammonia generation, and siderophore production. A significant increase in the growth of pea, chickpea, maize, and barley was recorded for inoculations under controlled conditions. Field testing with the pea also showed a significant increment in plant growth and yield. The rifampicin mutant of the bacterial strain effectively colonized the pea rhizosphere without adversely affecting the resident microbial populations. PMID:19137371

  1. Abrp, a new gene, confers reduced susceptibility to tetracycline, glycylcine, chloramphenicol and fosfomycin classes in Acinetobacter baumannii.

    Science.gov (United States)

    Li, X; Quan, J; Yang, Y; Ji, J; Liu, L; Fu, Y; Hua, X; Chen, Y; Pi, B; Jiang, Y; Yu, Y

    2016-08-01

    Acinetobacter baumannii, a non-fermenting gram-negative coccobacillus, is a major pathogen responsible for a variety of healthcare-associated infections, including pneumonia, urinary tract and bloodstream infections. Moreover, A. baumannii is associated with alarming increases in drug resistance rates to almost all available antibiotics leaving limited treatment options. Here, we characterize the biological functions of a novel gene, abrp, which encodes a peptidase C13 family. We demonstrate that the abrp is associated with decreased susceptibility to tetracycline, minocycline, doxycycline, tigecycline, chloramphenicol and fosfomycin. Deletion of abrp was able to increase cell membrane permeability and display slower cell growth rate. Results from the present study show that abrp plays an important role in conferring reduced susceptibility to different classes of antibiotics and cell growth in A. baumannii. The change of antibiotic sensitivities may result from modifications to the cell membrane permeability of A. baumannii. PMID:27220329

  2. In vitro synergy of colistin combinations against extensively drug-resistant Acinetobacter baumannii producing OXA-23 carbapenemase.

    Science.gov (United States)

    Wei, Wenjuan; Yang, Haifei; Liu, Yanyan; Ye, Ying; Li, Jiabin

    2016-06-01

    Fifty extensively drug-resistant Acinetobacter baumannii (XDRAB) were isolated from patients. The chequerboard microdilution method was used to determine the in vitro activities of five colistin (COL)-based combinations including COL+fosfomycin (FOS), COL+rifampicin (RIF), COL+imipenem (IMP), COL+sulbactam (SUP) and COL+levofloxacin (LVX). The synergistic activity was evaluated by the fractional inhibitory concentration index (FICI). According to our results, the combination of COL was synergistic with FOS, RIF, IMP, SUP and LVX with the ratios of 50, 72, 88, 92 and 64%, respectively. When combined with COL, the other five agents showed increased antimicrobial activities. In addition, two of the combinations, COL+RIF and COL+IMP, were more active than the combinations of COL+FOS, COL+SUP and COL+LVX. More importantly, these combination regimens could exert synergistic effects at the sub-minimum inhibitory concentration (MIC) levels against XDRAB strains. PMID:25978105

  3. Study of a hydrocarbon-utilizing and emulsifier-producing Acinetobacter calcoaceticus strain isolated from heating oil.

    Science.gov (United States)

    Marín, M M; Pedregosa, A M; Ortiz, M L; Laborda, F

    1995-12-01

    Twenty bacterial strains were isolated from a sample of contaminated heating oil and screened for their ability to use petroleum and several common fuels as the sole source of carbon and energy. One of the isolates, named MM5, was able to grow on petroleum derivatives and brought about an emulsification of those compounds. Gas chromatography studies showed that strain MM5 was able to degrade hydrocarbons of heating oil. MM5 has been tentatively identified as a strain of Acinetobacter calcoaceticus. The fine structure of MM5 was examined by transmission electron microscopy. Incubation in the presence of hydrocarbon substrates resulted in the development of intracellular electron-transparent inclusions. These structures were absent in the non-hydrocarbon cultures studied.

  4. Genome Sequence of a Clinical Strain of Acinetobacter baumannii Belonging to the ST79/PFGE-HUI-1 Clone Lacking the AdeABC (Resistance-Nodulation-Cell Division-Type) Efflux Pump.

    Science.gov (United States)

    López, M; Álvarez-Fraga, L; Gato, E; Blasco, L; Poza, M; Fernández-García, L; Bou, G; Tomás, M

    2016-01-01

    Increased expression of chromosomal genes for resistance-nodulation-cell division-type efflux systems plays a major role in the multidrug resistance of Acinetobacter baumannii Little is known about the genetic characteristics of clinical strains of Acinetobacter baumannii lacking the AdeABC pump. In this study, we sequenced the genome of clinical strain Ab421 GEIH-2010 (belonging to clone ST79/PFGE-HUI-1 from the GEIH-REIPI Ab. 2010 project) which lacks this efflux pump. PMID:27609928

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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. PMID:27448835

  7. Acinetobacter Baumannii Clinical Distribution and Drug Sensitivity Analysis%鲍曼不动杆菌的临床分布及药敏结果分析

    Institute of Scientific and Technical Information of China (English)

    钟志宏; 李启星

    2012-01-01

    Objective Learn Acinetobacter baumannii (ABA) the clinical characteristics of the distribution, clinical isolation rate, and its antibiotic sensitivity and resistance trends in clinical medicine for hospital treatment and prevention of Acinetobacter baumannii nosocomial infections were caused by experimental basis. Methods Retrospective analysis of Changsha a Hospital from August 2009 to October 2011 submission of clinical specimens isolated Acinetobacter baumannii. Results August 2009 to October 2011, a total of 653 isolated Acinetobacter baumannii in a non-fermenting bacteria,the Acinetobacter accounted for the first, the detection rate from 6.09% in the second half of 2009, followed in 2011 rose to 8.91 percent. Distribution of clinical departments to ICU ward, followed by the Department of Neurology. 22 antibacterial drugs, polymyxin E-resistant to the lowest, followed by imipenem. Conclusion Acinetobacter baumannii clinical specimens in a high detection rate, and there is a rising trend,Resistance strong, the phenomenon of multi-drug resistant serious, and the majority are located in critical surgical departments or wards.%目的:了解鲍曼不动杆菌(ABA)的临床分布特点,临床分离率,及其对抗生素的敏感性与耐药趋势,为医院临床用药治疗及预防鲍曼不动杆菌引起的院内感染提供实验依据.方法:回顾分析长沙市某医院2009年8月至2011年10月临床送检标本中分离出的鲍曼不动杆菌与药敏试验.结果:2009年8月至2011年10月共分离出653株鲍曼不动杆菌,在不动杆菌属中占第一位,检出率自2009年下半年的6.09%依次上升至2011年的8.91%.临床科室分布以ICU病房为主,其次是神经内科.22种抗菌药物中,以多粘菌素E耐药率最低,亚胺培南次之.结论:鲍曼不动杆菌在临床标本中的检出率有逐年增加的趋势,耐药性强,多重耐药现象严重,且多数分布在手术科室或危重病房中.

  8. 鲍曼不动杆菌感染的高危因素的分析%The risk factors for nosocomial infection caused by Acinetobacter baumanii

    Institute of Scientific and Technical Information of China (English)

    张玲; 欧阳玲; 尚碧莲; 孙光伟; 邸玥莹; 马莉; 王厚照

    2011-01-01

    Objective To analyze the risk factors for nosocomial infection caused by Acinetobacter baumanii in our hospital. Methods 187 patients clinical data infected by Acinetobacter baumanii from January to December in 2010 in our hospital were collected, and the risk factors for nosocomial infection caused by Acinetobacter baumanii were analyzed by muti-factor logistic regression analysis. Results Ventilator applied, intensive care unit(ICU)stay, previous use of third generation cephalosporin antibiotics and indwelling catheter were independent risk factors for nosocomial infection caused by Acinetobacter baumanii[odd ratios(OR) = 39. 242,19. 651,4. 534 ,3. 439 ,P<0. 01]. Conclusion It is important to prevent nosocomial infection caused by Acinetobacter baumanii by strict limitation on the indication of ICU stay,the use of ventilator,third generation cephalosporin antibiotics and indwelling catheter,and target monitoring of nosocomial infection caused by Acinetobacter baumanii in our hospital should be strengthened.%目的 对该院鲍曼不动杆菌(Ab)感染的危险因素进行分析.方法 收集2010年1~12月该院187例感染Ab住院患者的临床资料,采用多因素logistic回归方法 分析感染Ab的危险因素.结果 使用呼吸机、入住ICU、前期大量使用3代头孢和泌尿道插管是Ab感染的独立危险因素(比值比分别为39.242、19.651、4.534、3.439,P<0.05).结论 严格把握入住ICU、前期3代头孢大量使用、呼吸机及泌尿道插管的使用,及时进行医院感染的检测,对控制Ab所引发的医院感染具有突出的临床意义.

  9. 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

  10. PATTERN OF ANTIMICROBIAL RESISTANCE IN CLINICAL ISO LATES OF ACINETOBACTER SPECIES AT A TERTIARY LEVEL HEALTH CA RE FACILITY IN NORTHERN INDIA

    Directory of Open Access Journals (Sweden)

    Pooja

    2013-01-01

    Full Text Available ABSTRACT: BACKGROUND: Multi drug resistant Acinetobacter species is a rapi dly emerging pathogen in health care settings and has limited the options for effective treatment. It is increasingly reported as the cause of outbreaks and nosocomial infections such as blood-stream infections, ventilator-associated pneumonia, urinary tract infections and wound infections. AIM: The present study was undertaken to isolate and iden tify the multi drug resistant (MDR and extensively drug resistant (XDR Acinetobacter speci es. DESIGN AND SETTINGS: This is a prospective study conducted over a period of two years (September 2009 to August 2011 in a tertiary care hospital. Clinical samples were collect ed from both indoor and outdoor patients, irrespective of age and sex. MATERIALS AND METHODS: Three hundred non duplicate clinical isolates of Acinetobacter species were processed for species identification by standard Microbiological procedures. Antimicrobial susceptibil ity of these isolates was performed by Kirby-Bauer disc diffusion method. RESULTS: Of the 300 isolates, 224 (74.6% were identified as A. baumannii followed by A. lwoffii 73/300 (24.3 % and A. haemolyticus 3/300 (1%. Majority of the isolates were recovered from ICU pat ients 183/300 (61%, followed by patients admitted in wards 93/300 (31% and 24/300 (8% isol ates were from outdoor patients. Out of 300, 153 (51% isolates were XDR and 11% were MDR. Only about 10% of the isolates were sensitive to β-lactams and 30-40% of the strains we re sensitive to aminoglycosides and fluoroquinolones. None of the isolate was resistant to cefoperazone sulbactam, ceftriaxone sulbactam and polymyxins. Statistically significant difference (p value <0.001 was noticed between antibiotic resistance of A. baumannii and A . lwoffii. CONCLUSION: The increasing trends towards antibiotic resistance reflect the ex tensive use of antibiotics in hospitals which in turn exerts selective pressure on Acinetobacter in h ospital

  11. SP-A and SP-D in host defense against fungal infections and allergies.

    Science.gov (United States)

    Pandit, Hrishikesh; Madhukaran, Shanmuga P; Nayak, Annapurna; Madan, Taruna

    2012-01-01

    Innate immunity mediated by pattern recognition proteins is relevant in the host defense against fungi. SP-A and SP-D are two such proteins belonging to the class of collagen domain containing C-type lectins, or collectins. They bind to the sugar moieties present on the cell walls of various fungi in a dose dependent manner via their carbohydrate recognition domain (CRD). SP-A and SP-D directly interact with alveolar macrophages, neutrophils, lymphocytes. We review these roles of SP-A and SP-D against various clinically relevant fungal pathogens and fungal allergens. SP-A and SP-D gene deficient mice showed increased susceptibility/ resistance to various fungal infections. Patients of fungal infections and allergies are reported with alterations in the serum or lung lavage levels of SP-A and SP-D. There are studies associating the gene polymorphisms in SP-A and SP-D with alterations in their levels or functions or susceptibility of the host to fungal diseases. In view of the protective role of SP-D in murine models of Aspergillus fumigatus infections and allergies, therapeutic use of SP-D could be explored further.

  12. Acinetobacter spp. e Pseudomonas aeruginosa resistentes aos carbapenêmicos no Hospital Universitário de Santa Maria, Rio Grande do Sul = Carbapenem-resistant Acinetobacter spp. and Pseudomonas aeruginosa at the University Hospital of Santa Maria, Rio Grande do Sul state, Brazil

    Directory of Open Access Journals (Sweden)

    Brezolin, Daiane

    2014-01-01

    Conclusões: Neste estudo Acinetobacter spp. e P. aeruginosa apresentaram elevada resistência aos antimicrobianos. A polimixina B mostrou-se um bom antimicrobiano para o tratamento de infecções por microrganismos resistentes aos carbapenêmicos neste nosocômio

  13. Potensi Tanaman Ornamental (Aglaonema sp., Dieffenbachia sp., dan Spathiphyllum sp.) dalam Menurunkan Jumlah Mikroba Udara dalam Ruangan Kelas Sekolah Dasar

    OpenAIRE

    Mangunsong, Sisca Nency Teresia

    2016-01-01

    Bioaerosol is dust particles consisting of bacteria and other fungi with spores that are in the room when the temperature and humidity level are adequate. Its presence in the room are generally harmless, but some time causes disease. This research was aims to determine the effect of ornamental plant Aglaonema sp., Dieffenbachia sp., and Spathiphyllum sp. on amount of bacteria and fungi in the class room. Bioaerosol isolation was performed according to the method of air sampling with three rep...

  14. Draft genome sequence of a multidrug-resistant New Delhi metallo-β-lactamase NDM-1-producing Acinetobacter pittii sequence type 207 isolate from China.

    Science.gov (United States)

    Wang, Jianfeng; Wu, Liyan; Xu, Liqun; Chen, Yu; Chen, Yan

    2016-09-01

    The increasing emergence of carbapenem-resistant Acinetobacter spp. worldwide has resulted in the limited availability of effective antimicrobial agents and has become a major public health concern. In this study, the draft genome sequence of Acinetobacter pittii TCM292 belonging to sequence type 207 (ST207), a multidrug-resistant (MDR) isolate harbouring the New Delhi metallo-β-lactamase blaNDM-1 gene, was determined using an Illumina HiSeq™ 2000 platform. The genome sequence was analysed by bioinformatics methods. The A. pittii TCM292 genome size was estimated to be 3791758bp with 3486 predicted coding regions. These data might facilitate further understanding of the specific genomic features of MDR A. pittii in China. PMID:27530847

  15. 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

    sulfamethoxazole-resistant contained sulII (96%; 129/134) and/or sulI (14%; 19/134) (as part of class I integrons). sulII and tet(39) were located on plasmids differing in size in the isolates tested. Conclusions: The study shows tet(39) and sulII to be common resistance genes among clonally distinct Acinetobacter...... spp. from integrated fish farms and these bacteria may constitute reservoirs of resistance genes that may increase owing to a selective pressure caused by the use of antimicrobials in the overlaying animal production.......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...

  16. First Preliminary Report on Isolation and Characterization of Novel Acinetobacter spp. in Casing Soil Used for Cultivation of Button Mushroom, Agaricus bisporus (Lange Imbach

    Directory of Open Access Journals (Sweden)

    D. K. Choudhary

    2011-01-01

    Full Text Available Despite evaluation of large number of agroindustrial wastes for their use as casing material for Agaricus bisporus (Lange Imbach cultivation, scant attention has been given to the importance of biological properties of casing materials. In the present study, an attempt was made to characterize the bacterial flora in casing layer, namely, Farm Yard Manure (FYM and Spent Mushroom Substrate/spent compost (SMS/SC (FYM+SC, 3 : 1 and FYM and Vermi Compost (VC (FYM+VC, 3 : 1, employing partial 16S rDNA sequencing. Available data showed a significant variety of organisms that included Acinetobacter and Pseudomonas of the γ-proteobacteria, that were the most frequently encountered genera. This is the first preliminary report on the microbial diversity of casing soils and demonstrates the presence of Acinetobacter spp. that has not been previously described in casing material.

  17. Research advance in clinical multi-drug resistant Acinetobacter baumannii%临床多重耐药鲍曼不动杆菌的研究进展

    Institute of Scientific and Technical Information of China (English)

    陆坤; 胡志东

    2013-01-01

    随着新型广谱抗菌药物的广泛应用,鲍曼不动杆菌的耐药率逐年升高,多重耐药甚至泛耐药鲍曼不动杆菌的临床分离率明显增高.此文对近年来国内外多重耐药鲍曼不动杆菌感染的耐药机制、分型检测方法及临床治疗作一综述.%With the extensive use of new broad-spectrum antibiotics,the resistant rate of Acinetobacter baumannii has increased gradually.While the clinical isolates of multi-drug resistant and pan-resistant Acinetobacter baumanniihave also increased significantly.In this review,the resistant mechanisms,typing methods and treatment of multi-drug resistant A cinetobacter baumanii are summarized.

  18. Draft genome sequence of a multidrug-resistant New Delhi metallo-β-lactamase NDM-1-producing Acinetobacter pittii sequence type 207 isolate from China.

    Science.gov (United States)

    Wang, Jianfeng; Wu, Liyan; Xu, Liqun; Chen, Yu; Chen, Yan

    2016-09-01

    The increasing emergence of carbapenem-resistant Acinetobacter spp. worldwide has resulted in the limited availability of effective antimicrobial agents and has become a major public health concern. In this study, the draft genome sequence of Acinetobacter pittii TCM292 belonging to sequence type 207 (ST207), a multidrug-resistant (MDR) isolate harbouring the New Delhi metallo-β-lactamase blaNDM-1 gene, was determined using an Illumina HiSeq™ 2000 platform. The genome sequence was analysed by bioinformatics methods. The A. pittii TCM292 genome size was estimated to be 3791758bp with 3486 predicted coding regions. These data might facilitate further understanding of the specific genomic features of MDR A. pittii in China.

  19. DISTRIBUSI Solen sp DI PERAIRAN KABUPATEN BANGKALAN

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    Eva Ari Wahyuni

    2016-03-01

    Full Text Available DISTRIBUTION OF Solen sp IN BANGKALAN WATERSSolen sp potential needs to be developed on the island of Madura, particularly in Bangkalan. Solen sp utilization has increased which has the potential to overfishing. Therefore, this study aims to determine the density of Solen sp and their ecology in the waters Modung village, Modung District, Bangkalan. The experiment was conducted in April 2015 using the descriptive method. The materials used include Solen sp and physico-chemical parameters of the environment (temperature, salinity, pH, and substrate. The analyzes were conducted at the Laboratory of Marine Science, Department of Marine Sciences, Trunojoyo University of Madura by using the tool grabsampler, sieveshaker, and pipetting with gravimetric method. The analysis shows the range of values of temperature between 29-300C, salinity between 31-32 ppt, pH were 7.9-8.0 and the type of substrate in the form of sandy mud, as well as the density of Solen sp from 8-10 individuals/m2. All measurement results indicate normal conditions and in accordance with the sea water quality standard for marine life, which can be a suitable habitat for the growth and development of Solen sp. This condition is thought to affect the density of Solen sp.Keywords: Bangkalan, density, distribution, Solen sp, substrate.ABSTRAKPotensi Solen sp perlu dikembangkan di pulau Madura, khususnya di Kabupaten Bangkalan. Pemanfaatan Solen sp mengalami peningkatan sehingga berpotensi overfishing. Untuk itu, penelitian ini bertujuan untuk mengetahui kepadatan Solen sp dan ekologinya di perairan desa Modung, Kecamatan Modung, Kabupaten Bangkalan. Penelitian dilaksanakan pada bulan April 2015 dengan metode deskriptif. Materi dan bahan yang digunakan diantaranya Solen sp dan parameter fisika-kimia lingkungan (suhu, salinitas, pH, dan substrat. Analisa dilakukan di Laboratorium Ilmu Kelautan, Program studi/Jurusan Ilmu Kelautan Universitas Trunojoyo Madura dengan menggunakan alat

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

    Directory of Open Access Journals (Sweden)

    Sílvia Cristina Benetti

    2010-02-01

    Full Text Available

    This research had as main objectives the evaluation of cedar’s seeds seed-borne fungi and the Fusarium
    sp. and Pestalotia sp. pathogenicities. For the fungi detection Potato Dextrose and Agar medium and Blotter
    test methods were used. For the pathogenicity tests, isolates of Fusarium sp. and Pestalotia sp. were used. The following fungi were observed: Pestalotia sp., Fusarium sp., Phomopsis sp., Colletotrichum sp., Macrophomina sp. and Cladosporium sp. The fungi observed in the highest frequencies were: Fusarium sp., Phomopsis sp. and Pestalotia sp. A reduction of the germination level was observed in seedlings from cedar’s seed inoculated with Fusarium sp.

     

    doi: 10.4336/2009.pfb.58.81

    Este trabalho teve por objetivos avaliar fungos em sementes de cedro e testar a patogenicidade de Fusarium sp. e Pestalotia sp. Para detecção de fungos, foram utilizados batata-dextrose-ágar e papel filtro. Para o teste de patogenicidade, utilizaram-se isolados de Fusarium sp. e de Pestalotia sp. Foi constatada a presença dos seguintes fungos nas sementes: Pestalotia sp., Fusarium sp., Phomopsis sp., Colletotrichum sp., Macrophomina sp. e Cladosporium sp. Os fungos de maior freqüência foram: Fusarium sp., Phomopsis sp. e Pestalotia sp. Observou-se decréscimo nos valores de emergência das plântulas oriundas das sementes inoculadas com Fusarium sp.

     

    Doi: 10.4336/2009.pfb.58.81

  1. Pharmacodynamics of the Antibacterial Effect of and Emergence of Resistance to Doripenem in Pseudomonas aeruginosa and Acinetobacter baumannii in an In Vitro Pharmacokinetic Model

    OpenAIRE

    Bowker, Karen E.; Noel, Alan R.; Tomaselli, Sharon G.; Elliott, Heather; MacGowan, Alasdair P.

    2012-01-01

    An in vitro dilutional pharmacokinetic model of infection was used to study the pharmacodynamics of doripenem in terms of the ability to kill Pseudomonas aeruginosa or Acinetobacter baumannii and also changes in their population profiles. In dose-ranging studies, the cumulative percentages of a 24-h period that the drug concentration exceeds the MIC under steady-state pharmacokinetic conditions (TMICs) required for doripenem to produce a 24-h bacteriostatic effect and a −2-log-unit reduction ...

  2. An Exocellular Protein from the Oil-Degrading Microbe Acinetobacter venetianus RAG-1 Enhances the Emulsifying Activity of the Polymeric Bioemulsifier Emulsan

    OpenAIRE

    Bach, Horacio; Berdichevsky, Yevgeny; Gutnick, David

    2003-01-01

    The oil-degrading microorganism Acinetobacter venetianus RAG-1 produces an extracellular polyanionic, heteropolysaccharide bioemulsifier termed emulsan. Emulsan forms and stabilizes oil-water emulsions with a variety of hydrophobic substrates. Removal of the protein fraction yields a product, apoemulsan, which exhibits much lower emulsifying activity on hydrophobic substrates such as n-hexadecane. One of the key proteins associated with the emulsan complex is a cell surface esterase. The este...

  3. Genomic comparison of multi-drug resistant invasive and colonizing Acinetobacter baumannii isolated from diverse human body sites reveals genomic plasticity

    OpenAIRE

    Hsiao William W; Phillippy Adam M; Harris Anthony D; Johnson J Kristie; Sahl Jason W; Thom Kerri A; Rasko David A

    2011-01-01

    Abstract Background Acinetobacter baumannii has recently emerged as a significant global pathogen, with a surprisingly rapid acquisition of antibiotic resistance and spread within hospitals and health care institutions. This study examines the genomic content of three A. baumannii strains isolated from distinct body sites. Isolates from blood, peri-anal, and wound sources were examined in an attempt to identify genetic features that could be correlated to each isolation source. Results Pulsed...

  4. Prevalence of class1, 2 and 3 integrons among extensive drug resistance Acinetobacter baumanii strains isolated from intensive care units in Hamadan, west province, Iran

    OpenAIRE

    Fatemeh abestani, 1Mina Safari, 2Ghodratollah Roshanaii, 1Mohammad Yousef Alikhani Moammadi; Mohammad Reza Arabestani; Mina Safari; Ghodratollah Roshanaii; Mohammad Yousef Alikhani

    2014-01-01

    Background and Aim: Acinetobacter baumannii is opportunistic, gram negative, aerobic and nonfermentative coccobacilli. It is difficult to control and eradicate these bacteria, because of increased resistance to last-line antibiotic therapy and high peripheral resistance. The purpose of this study was to determine the prevalence of integron  and its relationship with the antibiotic resistance in A. baumannii. Materials and Methods: 100 isolates of A. baumannii were ...

  5. Association of Single Nucleotide Polymorphisms in Toll-like Recep¬tors with Acinetobacter baumanii Infectionin a Chinese Popu¬lation

    OpenAIRE

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

    2016-01-01

    Background: During recent years, infection of Acinetobacter baumanii showed a rapid growth in hospitals and community. Toll-like receptors (TLRs) are the most important pattern recognition receptors, which play a critical role during recognizing invading pathogens by the natural immune system. Our objective was to determine the associations of TLRs polymorphisms with the susceptibility to A. baumanii infection in a Chinese population.Methods: We carried out a case-control study, genotyping 13...

  6. Draft Genome Sequence of Colistin-Resistant Acinetobacter baumannii Strain VB22595 Isolated from a Central Line-Associated Bloodstream Infection.

    Science.gov (United States)

    Veeraraghavan, Balaji; Anandan, Shalini; Ragupathi, Naveen Kumar Devanga; Vijayakumar, Saranya; Sethuvel, Dhiviya Prabaa Muthuirulandi; Biswas, Indranil

    2016-01-01

    Acinetobacter baumannii is an important emerging pathogen that causes health care-associated infections. In this study, we determined the genome of a multidrug-resistant clinical strain, VB22595, isolated from a hospital in Southern India. The draft genome indicates that strain VB22595 encodes a genome of ~3.92 Mb in size and does not contain plasmid derived MCR-1 for colistin resistance. PMID:27516521

  7. Extremely high prevalence of antiseptic resistant Quaternary Ammonium Compound E gene among clinical isolates of multiple drug resistant Acinetobacter baumannii in Malaysia

    OpenAIRE

    Babaei, Mohammad Reza; Sulong, Anita; Hamat, Rukman Awang; Nordin, Syafinaz Amin; Neela, Vasantha Kumari

    2015-01-01

    Background Antiseptics are commonly used for the management of MDR (multiple drug resistance) pathogens in hospitals. They play crucial roles in the infection control practices. Antiseptics are often used for skin antisepsis, gauze dressing, preparation of anatomical sites for surgical procedure, hand sterilization before in contact with an infected person, before an invasive procedure and as surgical scrub. Methods We screened 122 multiple drug resistant Acinetobacter baumannii (MDRAB) isola...

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Acinetobacter baumannii Infection in Prior ICU Bed Occupants Is an Independent Risk Factor for Subsequent Cases of Ventilator-Associated Pneumonia

    Directory of Open Access Journals (Sweden)

    Eirini Tsakiridou

    2014-01-01

    Full Text Available Objective. We aimed to evaluate risk factors for ventilator-associated pneumonia (VAP due to Acinetobacter baumannii (AbVAP in critically ill patients. Methods. This was a prospective observational study conducted in an intensive care unit (ICU of a district hospital (6 beds. Consecutive patients were eligible for enrolment if they required mechanical ventilation for >48 hours and hospitalization for >72 hours. Clinical, microbiological, and laboratory parameters were assessed as risk factors for AbVAP by univariate and multivariate analysis. Results. 193 patients were included in the study. Overall, VAP incidence was 23.8% and AbVAP, 11.4%. Previous hospitalization of another patient with Acinetobacter baumannii infection was the only independent risk factor for AbVAP (OR (95% CI 12.016 (2.282–19.521 P<0.001. ICU stay (25±17 versus 12±9   P<0.001, the incidence of other infections (OR (95% CI 9.485 (1.640–10.466 P=0.002 (urinary tract infection, catheter related infection, and bacteremia, or sepsis (OR (95% CI 10.400 (3.749–10.466 P<0.001 were significantly increased in patients with AbVAP compared to patients without VAP; no difference was found with respect to ICU mortality. Conclusion. ICU admission or the hospitalization of patients infected by Acinetobacter baumannii increases the risk of AbVAP by subsequent patients.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 鲍曼不动杆菌107株感染的分布与耐药性%Acinetobacter baumannii infection in 107 tribution and drug resistance

    Institute of Scientific and Technical Information of China (English)

    马艳; 李俊伟; 翟金翎; 吴莉

    2009-01-01

    目的 分析鲍曼不动杆菌的标本来源、分布及耐药变迁趋势,为有效预防控制感染、指导临床合理用药提供依据.方法 采用VTTEK-32型自动微生物鉴定/药敏分析系统进行菌株鉴定及药物敏感性测试,耐药性数据分析采用WHONET5软件.结果 3年间分离出107株鲍曼不动杆菌,其对12种抗菌药物活性较好的是亚胺培南、阿米卡星、氨苄西林/舒巴坦,耐药率为0.9%、5.6%、6.5%;耐药率较高的是氨苄西林74.8%、头孢曲松钠63.6%、头孢噻肟钠38.3%,氨曲南25.2%.2008年与2006和2007年相比较,鲍曼不动杆菌的耐药率均有逐年上升的趋势.结论 本院监测结果显示鲍曼不动杆菌对碳青霉烯类、氨基糖苷类、β-内酰胺酶抑制剂复合药物保持较好的敏感性,但鲍曼不动杆菌临床分布逐年增加,耐药率逐渐上升.%Objective To investigate the variations of tendency of drug-resistance from Jan 2006 to Dec 2008. the origin and the distributing of Acinetobacter baumannii and provide basis for selection of clinical drugs.Methods The characteriztion and sensitivity to antibiotics of Acinetobacter baumannii were analysed using VTTEK-32 system.Results 107 strains of Acinetobacter baumannii were separated and characterized during the three years.The rates of resistance to antibiotics were Imipenem 0.9%,Amikacin 5.6%,Ampicillin/Sulbactam 6.5%,Ampicillin 74.8% Ceftriaone 63.6%,Cefotaxime 38.3%,Aztreonam 25.2%.The resistance rate of Acinetobacter baumanii increased from 2006 to 2008,showed increasing tendency.Conclusion Acinetobacter baumannii showed good sensitivity to Carbapenems,Aminoglycosides,β-lactam antibiotics,Acinetobacter baumanii are widely distributing in hospital and are widely resistant to many kinds of antibiotics,The results suggested that the resistance of Acinetobacter baumannii to antibiotics should be continuously monitored,it will be beneficial for infection-control to collect antibiotics basing on the

  13. 重症监护病房鲍曼不动杆菌耐药性分析%Antibiotics resistance of Acinetobacter baumannii in intensive care unit

    Institute of Scientific and Technical Information of China (English)

    邓健康; 郭晓兰

    2015-01-01

    Objective To investigate the specimen source and antibiotics resistance of Acinetobacter baumannii isolated from in‐patient in Intensive Care Unit(ICU) .Methods Specimen source and antibiotics resistance of 520 strains of Acinetobacter bauman‐nii ,isolated from patients of ICU in Affiliated Hospital of North Sichuan Medical College from 2011 to 2014 ,were retrospectively analyzed .Results The main source of Acinetobacter baumannii was sputum specimens ,accounting for 90 .4% .Acinetobacter bau‐mannii isolates showed the lowest resistance rates to cefoperazone‐sulbactam and minocycline(32 .0% and 25 .2% ,respectively) .A‐bout 68 .1% and 74 .9% of these strains were resistant to trimethoprim‐sulfamethoxazole and levofloxacin ,respectively .More than 86 .0% of the strains were resistant to other tested antibacterial agents .Conclusion Acinetobacter baumanii strains ,isolated from ICU ,could have high resistance rates to many kinds of antibacterial agents ,and cefoperazone‐sulbactam and minocycline might be with fine antibacterial activity against Acinetobacter baumanii .Drug resistance monitoring of Acinetobacter baumanii should be strengthened ,and antibacterial agents should be selected and used rationally according to the results of drug sensitivity test .%目的:了解分离自重症监护病房(IC U )送检标本鲍曼不动杆菌的标本来源和耐药性。方法回顾性分析2011~2014年分离自川北医学院附属医院IC U患者临床标本的520株鲍曼不动杆菌的临床分布和耐药性。结果鲍曼不动杆菌主要分离自痰液标本,占90.4%。鲍曼不动杆菌对头孢哌酮/舒巴坦和米诺环素的耐药率相对较低,分别为32.0%和25.2%;对复方磺胺甲噁唑和左旋氧氟沙星的耐药率分别为68.1%和74.9%;对其他常用抗菌药物的耐药率均超过86.0%。结论分离自IC U送检标本的鲍曼不动杆菌对多种抗菌药物耐药率高,对头孢哌酮/

  14. 49株鲍曼不动杆菌的耐药性分析%Resistance Analysis of 49 Strains of Acinetobacter Baumannii

    Institute of Scientific and Technical Information of China (English)

    周志坚

    2012-01-01

      Objective :To analysis resistance of 49 strains of acinetobacter baumannii for clinical control and treatment of acinetobacter baumannii provides the basis.Methods :From January 2010 to January 2011,specimens of secretions,cerebrospinal fluid,lung lavage fluid,sputum,purulent fluid in hospitalized patients were separated out of acinetobacter baumannii 49 strains,used VITEK-2 system to identify bacteria ;Drug sensitive test was conducted by antibiotics drug diffusion method ;acinetobacter baumannii resistance was analyzed by WHONET 5.4 analysis software.Results :Acinetobacter baumannii resistance had the grim situation,the separating and resistant rate were increasing year by year,and multiple resistance and the resistance ratio increased significantly.Resistance of seven clinical common antibiotic was tested in 49 strain of acinetobacter baumannii,the antibiotic resistance rate of gentamycin, meropenem,cefepime,ceftazidime,cefotaxime,ciprofloxacin,amikacin were 53.06%,32.65%,22.45%,32.65%,44.90%,30.61%,8.16%.Through the data,the antibiotic resistance rate of gentamycin was higher.Conclusion :Compound drug and active antibacterial agent are more effectively.The measures of cleaning the sanitary status in patient’s living space and improving immunity can help to control and treat acinetobacter baumannii.%  目的:对49株鲍曼不动杆菌的耐药性进行分析,为临床控制和治疗鲍曼不动杆菌提供依据.方法:以2010年1月-2011年1月笔者所在医院的住院患者伤口分泌物、脑脊液、肺灌洗液、痰液、脓液为标本,共分离出鲍曼不动杆菌49株,应用 VITEK-32系统进行细菌鉴定;抗菌药物纸片扩散法行药敏试验;WHONET 5.4软件分析鲍曼不动杆菌的耐药性.结果:鲍曼不动杆菌耐药形势严峻,其分离率和耐药率呈逐年上升趋势,且多重耐药和泛耐药比例明显增加.49株鲍曼不动杆菌对7种临床常用抗生素的耐药性测试

  15. Babesia sp. in Colombian bats (Microchiroptera).

    Science.gov (United States)

    Marinkelle, C J

    1996-07-01

    Two leaf-chinned bats (Mormoops megalophylla) collected in 1963 in central Colombia were heavily infected with Babesia sp., probably Babesia vesperuginis. Both bats had pronounced splenomegaly. This is the first report of a Babesia sp. infection of a bat in the Americas. PMID:8827683

  16. Glyphosate catabolism by Pseudomonas sp

    International Nuclear Information System (INIS)

    The pathway for the degradation of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. PG2982 has been determined using metabolic radiolabeling experiments. Radiorespirometry experiments utilizing [3-14C] glyphosate revealed that approximately 50-59% of the C3 carbon was oxidized to CO2. Fractionation of stationary phase cells labeled with [3-14C]glyphosate revealed that from 45-47% of the assimilated C3 carbon is distributed to proteins and that amino acids methionine and serine are highly labeled. The nucleic acid bases adenine and guanine received 90% of the C3 label that was incorporated into nucleic acids, and the only pyrimidine base labeled was thymine. Pulse labeling of PG2982 cells with [3-14C]glyphosate revealed that [3-14C]sarcosine is an intermediate in glyphosate degradation. Examination of crude extracts prepared from PG2982 cells revealed the presence of an enzyme that oxidizes sarcosine to glycine and formaldehyde. These results indicate that the first step in glyphosate degradation by PG2982 is cleavage of the carbon-phosphorus bond, resulting in the release of sarcosine and a phosphate group. The phosphate group is utilized as a source of phosphorus, and the sarcosine is degraded to glycine and formaldehyde. Phosphonate utilization by Pseudomonas sp. PG2982 was investigated. Each of the ten phosphonates tested were utilized as a sole source of phosphorus by PG2982. Representative compounds tested included alkylphosphonates, 1-amino-substituted alkylphosphonates, amino-terminal phosphonates, and an arylphosphonate. PG2982 cultures degraded phenylphosphonate to benzene and produced methane from methylphosphonate. The data indicate that PG2982 is capable of cleaving the carbon-phosphorus bond of several structurally different phosphonates

  17. Listeria floridensis sp. nov., Listeria aquatica sp. nov., Listeria cornellensis sp. nov., Listeria riparia sp. nov. and Listeria grandensis sp. nov., from agricultural and natural environments.

    Science.gov (United States)

    den Bakker, Henk C; Warchocki, Steven; Wright, Emily M; Allred, Adam F; Ahlstrom, Christina; Manuel, Clyde S; Stasiewicz, Matthew J; Burrell, Angela; Roof, Sherry; Strawn, Laura K; Fortes, Esther; Nightingale, Kendra K; Kephart, Daniel; Wiedmann, Martin

    2014-06-01

    Sampling of agricultural and natural environments in two US states (Colorado and Florida) yielded 18 Listeria-like isolates that could not be assigned to previously described species using traditional methods. Using whole-genome sequencing and traditional phenotypic methods, we identified five novel species, each with a genome-wide average BLAST nucleotide identity (ANIb) of less than 85% to currently described species. Phylogenetic analysis based on 16S rRNA gene sequences and amino acid sequences of 31 conserved loci showed the existence of four well-supported clades within the genus Listeria; (i) a clade representing Listeria monocytogenes, L. marthii, L. innocua, L. welshimeri, L. seeligeri and L. ivanovii, which we refer to as Listeria sensu stricto, (ii) a clade consisting of Listeria fleischmannii and two newly described species, Listeria aquatica sp. nov. (type strain FSL S10-1188(T) = DSM 26686(T) = LMG 28120(T) = BEI NR-42633(T)) and Listeria floridensis sp. nov. (type strain FSL S10-1187(T) = DSM 26687(T) = LMG 28121(T) = BEI NR-42632(T)), (iii) a clade consisting of Listeria rocourtiae, L. weihenstephanensis and three novel species, Listeria cornellensis sp. nov. (type strain TTU A1-0210(T) = FSL F6-0969(T) = DSM 26689(T) = LMG 28123(T) = BEI NR-42630(T)), Listeria grandensis sp. nov. (type strain TTU A1-0212(T) = FSL F6-0971(T) = DSM 26688(T) = LMG 28122(T) = BEI NR-42631(T)) and Listeria riparia sp. nov. (type strain FSL S10-1204(T) = DSM 26685(T) = LMG 28119(T) = BEI NR- 42634(T)) and (iv) a clade containing Listeria grayi. Genomic and phenotypic data suggest that the novel species are non-pathogenic.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Differences in Acinetobacter baumannii strains and host innate immune response determine morbidity and mortality in experimental pneumonia.

    Directory of Open Access Journals (Sweden)

    Anna de Breij

    Full Text Available Despite many reports documenting its epidemicity, little is known on the interaction of Acinetobacter baumannii with its host. To deepen our insight into this relationship, we studied persistence of and host response to different A. baumannii strains including representatives of the European (EU clones I-III in a mouse pneumonia model. Neutropenic mice were inoculated intratracheally with five A. baumannii strains and an A. junii strain and at several days morbidity, mortality, bacterial counts, airway inflammation, and chemo- and cytokine production in lungs and blood were determined. A. baumannii RUH875 and RUH134 (EU clone I and II, respectively and sporadic strain LUH8326 resulted in high morbidity/mortality, whereas A. baumannii LUH5875 (EU clone III, which is less widespread than clone I and II caused less symptoms. A. baumannii type strain RUH3023(T and A. junii LUH5851 did not cause disease. All strains, except A. baumannii RUH3023(T and A. junii LUH5851, survived and multiplied in the lungs for several days. Morbidity and mortality were associated with the severity of lung pathology and a specific immune response characterized by low levels of anti-inflammatory (IL-10 and specific pro-inflammatory (IL-12p40 and IL-23 cytokines at the first day of infection. Altogether, a striking difference in behaviour among the A. baumannii strains was observed with the clone I and II strains being most virulent, whereas the A. baumannii type strain, which is frequently used in virulence studies appeared harmless.

  20. Inhibitory effects of reserpine and carbonyl cyanide m-chloro-phenylhydrazone on fluoroquinolone resistance of Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    SHI Wei-feng; JIANG Jian-ping; XU Ning; HUANG Zhi-mi; WANG Yu-yue

    2005-01-01

    @@ Mechanisms of bacterial resistance to fluoro-quinolones may be grouped into three principal categories: gene mutations of DNA topoisomerase Ⅱ (GyrA or GyrB), DNA topoisomerase Ⅳ (ParC or ParE), decrease of outer membrane permeation and upregulation of multi-drug efflux pump (active efflux system).1 Efflux pumps are transport proteins removing toxic substrates (including virtually all classes of clinically relevant antibiotics) from cells to the external environment. These proteins exist in both Gram positive bacteria and Gram negative bacteria as well as in fungi and mammalian (tumour) cells.2-4 It has been reported that alkaloid reserpine and carbonyl cyanide m-chlorophenylhydrazone (CCCP) can inhibit NorA multi-drug efflux.5,6 In order to explore the universality of drug efflux in microorganisms, 85 strains of Acinetobacter baumannii (A. Baumannii) were tested using reserpine and CCCP. The quinolone-resistant-determining region (QRDR) of gyrA and parC genes in 35 isolates of A. Baumannii were amplified by polymerase chain reaction (PCR) and sequenced by DNA sequencer. The correlation between resistant mutation regularity and bacterial drug efflux were analysed.

  1. Structure of the capsular polysaccharide of Acinetobacter baumannii 1053 having the KL91 capsule biosynthesis gene locus.

    Science.gov (United States)

    Shashkov, Alexander S; Shneider, Mikhail M; Senchenkova, Sof'ya N; Popova, Anastasiya V; Nikitina, Anastasia S; Babenko, Vladislav V; Kostryukova, Elena S; Miroshnikov, Konstantin A; Volozhantsev, Nikolay V; Knirel, Yuriy A

    2015-03-01

    Acinetobacter baumannii 1053 is the type strain for the maintenance of specific bacteriophage AP22, which infects a fairly broad range of A. baumannii strains circulating in Russian clinics and hospitals. A capsular polysaccharide (CPS) was isolated from cells of strain 1053 and studied by sugar analysis along with 1D and 2D (1)H and (13)C NMR spectroscopy. The following structure of the linear trisaccharide repeating unit was established: -->4)-β-D-ManpNAcA-(1-->4)-β-D-ManpNAcA-(1-->3)-α-D-FucpNAc-(1--> where ManNAcA and FucNAc indicate 2-acetamido-2-deoxymannuronic acid and 2-acetamido-2,6-dideoxygalactose, respectively. A polysaccharide having the same repeating unit but a shorter chain was isolated by the phenol-water extraction of bacterial cells. Sequencing of the CPS biosynthesis gene locus showed that A. baumannii 1053 belongs to a new group designated KL91. The gene functions assigned putatively by a comparison with available databases were in agreement with the CPS structure established.

  2. Transmission Electron Microscopic Morphological Study and Flow Cytometric Viability Assessment of Acinetobacter baumannii Susceptible to Musca domestica cecropin

    Directory of Open Access Journals (Sweden)

    Shuiqing Gui

    2014-01-01

    Full Text Available Multidrug-resistant (MDR Acinetobacter baumannii infections are difficult to treat owing to the extremely limited armamentarium. Expectations about antimicrobial peptides' use as new powerful antibacterial agents have been raised on the basis of their unique mechanism of action. Musca domestica cecropin (Mdc, a novel antimicrobial peptide from the larvae of Housefly (Musca domestica, has potently active against Gram-positive and Gram-negative bacteria standard strain. Here we evaluated the antibacterial activity of Mdc against clinical isolates of MDR-A. baumannii and elucidate the related antibacterial mechanisms. The minimal inhibitory concentration (MIC of Mdc was 4 μg/mL. Bactericidal kinetics of Mdc revealed rapid killing of A. baumannii (30 min. Flow cytometry using viability stain demonstrated that Mdc causes A. baumannii membrane permeabilization in a concentration- and time-dependent process, which correlates with the bactericidal action. Moreover, transmission electron microscopic (TEM examination showed that Mdc is capable of disrupting the membrane of bacterial cells, resulting in efflux of essential cytoplasmic components. Overall, Mdc could be a promising antibacterial agent for MDR-A. baumannii infections.

  3. Persistence of Multidrug-Resistant Acinetobacter baumannii Isolates Harboring blaOXA-23 and bap for 5 Years.

    Science.gov (United States)

    Sung, Ji Youn; Koo, Sun Hoe; Kim, Semi; Kwon, Gye Cheol

    2016-08-28

    The emergence and dissemination of carbapenemase-producing Acinetobacter baumannii isolates have been reported worldwide, and A. baumannii isolates harboring blaOXA-23 are often resistant to various antimicrobial agents. Antimicrobial resistance can be particularly strong for biofilm-forming A. baumannii isolates. We investigated the genetic basis for carbapenem resistance and biofilm-forming ability of multidrug-resistant (MDR) clinical isolates. Ninety-two MDR A. baumannii isolates were collected from one university hospital located in the Chungcheong area of Korea over a 5-year period. Multiplex PCR and DNA sequencing were performed to characterize carbapenemase and bap genes. Clonal characteristics were analyzed using REP-PCR. In addition, imaging and quantification of biofilms were performed using a crystal violet assay. All 92 MDR A. baumannii isolates involved in our study contained the blaOXA-23 and bap genes. The average absorbance of biomass in Bap-producing strains was much greater than that in non-Bap-producing strains. In our study, only three REP-PCR types were found, and the isolates showing type A or type B were found more than 60 times among unique patients during the 5 years of surveillance. These results suggest that the isolates have persisted and colonized for 5 years, and biofilm formation ability has been responsible for their persistence and colonization.

  4. 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. PMID:26471472

  5. Characterization of eDNA from the Clinical Strain Acinetobacter baumannii AIIMS 7 and Its Role in Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Praveen K. Sahu

    2012-01-01

    Full Text Available Release of extracellular DNA (eDNA was observed during in vitro growth of a clinical strain of Acinetobacter baumannii. Membrane vesicles (MV of varying diameter (20–200 nm containing DNA were found to be released by transmission electron microscopy (TEM and atomic force microscopy (AFM. An assessment of the characteristics of the eDNA with respect to size, digestion pattern by DNase I/restriction enzymes, and PCR-sequencing, indicates a high similarity with genomic DNA. Role of eDNA in static biofilm formed on polystyrene surface was evaluated by biofilm augmentation assay using eDNA available in different preparations, for example, whole cell lysate, cell-free supernatant, MV suspension, and purified eDNA. Biofilm augmentation was seen up to 224.64%, whereas biofilm inhibition was 59.41% after DNase I treatment: confirming that eDNA facilitates biofilm formation in A. baumannii. This is the first paper elucidating the characteristics and role of eDNA in A. baumannii biofilm, which may provide new insights into its pathogenesis.

  6. Characterization of eDNA from the clinical strain Acinetobacter baumannii AIIMS 7 and its role in biofilm formation.

    Science.gov (United States)

    Sahu, Praveen K; Iyer, Pavithra S; Oak, Amrita M; Pardesi, Karishma R; Chopade, Balu A

    2012-01-01

    Release of extracellular DNA (eDNA) was observed during in vitro growth of a clinical strain of Acinetobacter baumannii. Membrane vesicles (MV) of varying diameter (20-200 nm) containing DNA were found to be released by transmission electron microscopy (TEM) and atomic force microscopy (AFM). An assessment of the characteristics of the eDNA with respect to size, digestion pattern by DNase I/restriction enzymes, and PCR-sequencing, indicates a high similarity with genomic DNA. Role of eDNA in static biofilm formed on polystyrene surface was evaluated by biofilm augmentation assay using eDNA available in different preparations, for example, whole cell lysate, cell-free supernatant, MV suspension, and purified eDNA. Biofilm augmentation was seen up to 224.64%, whereas biofilm inhibition was 59.41% after DNase I treatment: confirming that eDNA facilitates biofilm formation in A. baumannii. This is the first paper elucidating the characteristics and role of eDNA in A. baumannii biofilm, which may provide new insights into its pathogenesis. PMID:22593716

  7. Imported PER-1 producing Pseudomonas aeruginosa, PER-1 producing Acinetobacter baumanii and VIM-2-producing Pseudomonas aeruginosa strains in Hungary

    Directory of Open Access Journals (Sweden)

    Nagy Károly

    2008-05-01

    Full Text Available Abstract Introduction Pseudomonas aeruginosa and Acinetobacter baumanii are important nosocomial pathogens with wide intrinsic resistance. However, due to the dissemination of the acquired resistance mechanisms, such as extended-spectrum beta-lactamase (ESBL and metallo beta-lactamase (MBL production, multidrug resistant strains have been isolated more often. Case presentation We report a case of a Hungarian tourist, who was initially hospitalized in Egypt and later transferred to Hungary. On the day of admission PER-1-producing P. aeruginosa, PER-1 producing A. baumannii, SHV-5-producing Klebsiella pneumoniae and VIM-2-producing P. aeruginosa isolates were subcultured from the patient's samples in Hungary. Comparing the pulsed-field gel electrophoresis (PFGE patterns of the P. aeruginosa strains from the patient to the P. aeruginosa strains occurring in this hospital, we can state that the PER-1-producing P. aeruginosa and VIM-2-producing P. aeruginosa had external origin. Conclusion This is the first report of PER-1-producing P. aeruginosa,and PER-1-producing A. baumanii strains in Hungary. This case highlights the importance of spreading of the beta-lactamase-mediated resistance mechanisms between countries and continents, showing the importance of careful screening and the isolation of patients arriving from a different country.

  8. Antimicrobial action of zinc oxide nanoparticles in combination with ciprofloxacin and ceftazidime against multidrug-resistant Acinetobacter baumannii.

    Science.gov (United States)

    Ghasemi, F; Jalal, R

    2016-09-01

    Acinetobacter baumannii is a serious concern amongst hospitalised patients worldwide and its resistance to antibiotics has emerged as a threat to public health in recent years. Metal oxide nanoparticles were found to be effective for overcoming bacterial resistance owing to their antibacterial activities. The aim of this study was to investigate the combined effects of zinc oxide nanoparticles (ZnO-NPs) and the conventional antibiotics ciprofloxacin and ceftazidime as well as their mechanisms of action against resistant A. baumannii. ZnO-NPs were prepared by the solvothermal method and were characterised by various methods. Broth microdilution and disk diffusion methods were used to determine the antibacterial activities of ciprofloxacin and ceftazidime antibiotics in the absence and presence of a subinhibitory concentration of ZnO-NPs. The mechanism of action of ZnO-NPs alone and in combination with these antibiotics was assessed by flow cytometry, DNA extraction, fluorescence and scanning electron microscopy. The results showed that the antibacterial activities of both antibiotics increased in the presence of a subinhibitory concentration of ZnO-NPs. Combination of ZnO-NPs with antibiotics increased the uptake of antibiotics and changed the bacterial cells from rod to cocci forms. Bacterial filamentation was also observed and exhibited no DNA fragmentation. In conclusion, the results of this study indicate that ZnO-NPs potentiate the antimicrobial action of ciprofloxacin and ceftazidime. A mechanism is proposed to explain this phenomenon. PMID:27530853

  9. Antibiotic resistance and carriage class 1 and 2 integrons in clinical isolates of Acinetobacter baumannii from Tehran, Iran

    Institute of Scientific and Technical Information of China (English)

    Reza Mirnejad; Sepideh Mostofi; Faramaz Masjedian

    2013-01-01

    Objective: To investigate antibiotic resistance and carriage class 1 and 2 integrons in clinical isolates of Acinetobacter baumannii (A. baumannii) from Tehran, Iran. Methods: Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute. The presence of integrons was investigated by PCR using specific primers. Results:Among isolated A. baumannii strains, 82%were multidrug resistant, 27 samples (54%) were resistant to three or more than three antibiotics and 16 samples (32%) showed resistance to two antibiotics. Integrons were detected from 44 of 50 isolates (88%), with classes 1 and 2 being observed in 42% (21/50) and 82%(41/50) of isolates, respectively. Integron-positive A. baumannii isolates showed higher antibiotic resistance than integron-negative isolates and all showed a multidrug-resistant phenotype. Conclusions:Our findings show that classes 1 and 2 integrons, and especially classes 2 integrons are widely disseminated among A. baumannii strains isolated from Tehran and these structures are playing a major role in the acquisition of multidrug resistance in these strains. So monitoring of drug resistance with investigating carriage class 1 and 2 integrons is very important to plan specific infection control measures due to multidrug resistance A. baumannii in Iran hospitals.

  10. Low-Frequency Ultrasound Enhances Antimicrobial Activity of Colistin-Vancomycin Combination against Pan-Resistant Biofilm of Acinetobacter baumannii.

    Science.gov (United States)

    Liu, Xu; Yin, Hong; Weng, Chun-Xiao; Cai, Yun

    2016-08-01

    Acinetobacter baumannii biofilms in catheters are very difficult to treat. Low-frequency ultrasound (LFU) may improve bactericidal or bacteriostatic activity. However, no previous studies have been reported on its efficacy against pan-resistant biofilms of A. baumannii. This study was designed to investigate whether LFU can enhance the activity of colistin, vancomycin and colistin-vancomycin combinations against pan-resistant biofilms of A. baumannii. The efficacy of colistin combinations was determined using the fractional inhibitory concentration index (FICI). The antibacterial effect was determined from bacteria counts in biofilms and the establishment of 24-h time-kill curves. A significantly synergistic effect was detected between colistin and vancomycin (FICI colistin in the combination treatments resulted in a better ultrasound-enhanced antibacterial effect. In 24-h time-kill curves, the combination of colistin (8 μg/mL) plus vancomycin (4 μg/mL) with LFU caused a significant reduction in bacteria counts in biofilms after 8 h and a continuing decline until 24 h. Bacterial counts were reduced by 3.77 log(CFU/mL) by LFU plus combinations, compared with combinations without LFU at 24 h. Our results indicate that LFU in combination with colistin plus vancomycin may be useful in treating pan-resistant A. baumannii infections. PMID:27131840

  11. The molecular epidemiological study of colistin-only-sensitive strains in multi-drug resistant Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    YANG Li; HAN Lizhong; SUN Jingyong; YU Yunsong; NI Yuxing

    2007-01-01

    This paper reported the epidemiology of the colistin-only-sensitive Acinetobacter baumannii(COS-AB)in a tertiary teaching hospital in China.We analyzed the clinical data of 136 COS-AB isolates from June 2004 to May 2005 and collected 66 A.baumannii isolates in which 33 strains were COS-AB,and the rest were non-COS-AB.Random amplified polymorphic DNA(RAPD)analysis (primer ERIC2 and 272)showed that all COS-AB were identical,while pulsed-field gel electrophotesis(PFGE)analysis showed two separate genotypes of these COS-ABwhich were distinctly different from that of non-COS-AB.The COS-AB from burn wards showed the identical PFGE pattern which was distinguished from the genotype of COS-AB in other departments,mainly surgical systems.The cross-infection was severe and strict methods of disinfection and sterilization should be implemented.Meanwhile,the epidemiology of COS-AB in environment and patients should be closely monitored.The PFGE analysis is a reliable method of A.baumannii typing.

  12. Transcriptomic analysis of colistin-susceptible and colistin-resistant isolates identifies genes associated with colistin resistance in Acinetobacter baumannii.

    Science.gov (United States)

    Park, Y K; Lee, J-Y; Ko, K S

    2015-08-01

    The emergence of colistin-resistant Acinetobacter baumannii is concerning, as colistin is often regarded as the last option for treating multidrug-resistant (MDR) A. baumannii infections. Using mRNA sequencing, we compared whole transcriptomes of colistin-susceptible and colistin-resistant A. baumannii strains, with the aim of identifying genes involved in colistin resistance. A clinical colistin-susceptible strain (06AC-179) and a colistin-resistant strain (07AC-052) were analysed in this study. In addition, a colistin-resistant mutant (06AC-179-R1) derived from 06AC-179 was also included in this study. High throughput mRNA sequencing was performed with an Illumina HiSeq TM 2000. In total, six genes were identified as associated with colistin resistance in A. baumannii. These six genes encode PmrAB two-component regulatory enzymes, PmrC (a lipid A phosphoethanolamine transferase), a glycosyltransferase, a poly-β-1,6-N-acetylglucosamine deacetylase, and a putative membrane protein. Matrix-assisted laser desorption/ionization time of flight mass spectrometry revealed that all three colistin-resistant strains used in this study had modified lipid A structure by addition of phosphoethanolamine. As genes found in our results are all associated with either lipopolysaccharide biosynthesis or electrostatic changes in the bacterial cell membrane, lipopolysaccharide modification might be one of the principal modes of acquisition of colistin resistance in some A. baumannii strains.

  13. The quorum sensing molecule N-acyl homoserine lactone produced by Acinetobacter baumannii displays antibacterial and anticancer properties.

    Science.gov (United States)

    John, James; Saranathan, Rajagopalan; Adigopula, Lakshmi Narayana; Thamodharan, Vasanth; Singh, Satya Prakash; Lakshmi, T Pragna; CharanTej, Mallu Abhiram; Rao, R Srinivasa; Krishna, R; Rao, H Surya Prakash; Prashanth, K

    2016-10-01

    Secretory N-acyl homoserine lactones (AHLs) mediate quorum sensing (QS) in bacteria. AHLs are shown to be inhibitory for an unrelated group of bacteria and might mimic host signalling elements, thereby subverting the regulatory events in host cells. This study investigated the AHL produced by Acinetobacter baumannii and analysed its effect on other bacterial species and mammalian cells. Chemically characterized AHL had an m/z value of 325 with a molecular formula C18H31NO4 and showed its inhibitory potential against Staphylococcus aureus. Molecular docking studies identified D-alanine-D-alanine synthetase A, a cell wall synthesizing enzyme of S. aureus having a strong binding affinity towards AHL. Electron microscopy showed the disruption and sloughing off of the S. aureus cell wall when treated with AHL. In vitro experiments revealed that this bacteriostatic AHL showed time-dependent activity and induced apoptosis in cancer cell lines. This compound could be a potential structural backbone for constructing new AHL analogues against S. aureus. The findings emphasize the need to re-evaluate all previously characterized AHLs for any additional new biological functions other than QS. PMID:27643959

  14. Novel cassette array in a class 1 integron in clinical isolates of Acinetobacter baumannii from central Iran.

    Science.gov (United States)

    Japoni-Nejad, Alireza; Farshad, Shohreh; van Belkum, Alex; Ghaznavi-Rad, Ehsanollah

    2013-12-01

    Antibiotic resistance in Acinetobacter baumannii is a major problem in the hospital and outbreaks caused by this organism have been reported frequently. The present study aimed at determining the antibiotic susceptibility patterns, the prevalence of different classes of integrons and the characterization of integron class 1 gene cassettes in Iranian A. baumannii isolates. A total of 63 non-duplicate A. baumannii isolates were collected from clinical and environmental specimens in the Vali-Asr hospital in the central province of Iran (March to September, 2011). The antimicrobial susceptibility for 15 antibiotics which are used conventionally was determined by disk diffusion. The presence of different integron classes was investigated by PCR and the size of gene cassettes in class 1 integrons was then determined by PCR as well. Moreover, integron cassette arrays of isolates were delineated by RFLP and sequencing amplicons with different lengths. Of 63 isolates 62 (98.4%) carried a class 1 integron. The prevalence of IntI2 was 15.9% and the length of the amplicons ranged from 500 bp to 3 kb. Sequencing of integrons of class 1 revealed the presence of many resistance genes (aadA, aacA, aacC, dfrA, bla(GES) and bla(IMP)). We identified a completely new gene cassette which contained aacA7-qacF-aadA5-bla(IMP), this cassette has not been reported previously in A. baumannii. PMID:24161711

  15. Diversity and Evolution of AbaR Genomic Resistance Islands in Acinetobacter baumannii Strains of European Clone I▿†

    Science.gov (United States)

    Krizova, Lenka; Dijkshoorn, Lenie; Nemec, Alexandr

    2011-01-01

    To assess the diversity of AbaR genomic resistance islands in Acinetobacter baumannii European clone I (MLST clonal complex 1), we investigated 26 multidrug-resistant strains of this major clone isolated from hospitals in 21 cities of 10 European countries between 1984 and 2005. Each strain harbored an AbaR structure integrated at the same position in the chromosomal ATPase gene. AbaR3, including four subtypes based on variations in class 1 integron cassettes, and AbaR10 were found in 15 and 2 strains, respectively, whereas a new, unique AbaR variant was discovered in each of the other 9 strains. These new variants, designated AbaR11 to AbaR19 (19.8 kb to 57.5 kb), seem to be truncated derivatives of AbaR3, likely resulting from the deletions of its internal parts mediated by either IS26 elements (AbaR12 to AbaR19) or homologous recombination (AbaR11). AbaR3 was detected in all 10 strains isolated in 1984 to 1991, while AbaR11 to AbaR19 were carried only by strains isolated since 1997. Our results and those from previous publications suggest that AbaR3 is the original form of AbaR in European clone I, which may have provided strains of the lineage with a selective advantage facilitating their spread in European hospitals in the 1980s or before. PMID:21537009

  16. Molecular Epidemiology of Carbapenem-Resistant Acinetobacter Baumannii Complex Isolates from Patients that were Injured During the Eastern Ukrainian Conflict.

    Science.gov (United States)

    Granzer, Heike; Hagen, Ralf Matthias; Warnke, Philipp; Bock, Wolfgang; Baumann, Tobias; Schwarz, Norbert Georg; Podbielski, Andreas; Frickmann, Hagen; Koeller, Thomas

    2016-06-24

    This study addressed carbapenem-resistant Acinetobacter baumannii complex (ABC) isolates from patients that were injured during the military conflict in the Eastern Ukraine and treated at German Armed Forces Hospitals in 2014 and 2015. Clonal diversity of the strains and potential ways of transmission were analyzed. Patients with one or several isolation events of carbapenem-resistant ABC were included. Isolates were characterized by VITEK II-based identification and resistance testing, molecular screening for frequent carbapenemase genes, and DiversiLab rep-PCR-based typing. Available clinical information of the patients was assessed. From 21 young male Ukrainian patients with battle injuries, 32 carbapenem- and fluoroquinolone-resistant ABC strains were isolated. Four major clonal clusters were detected. From four patients (19%), ABC isolates from more than one clonal cluster were isolated. The composition of the clusters suggested transmission events prior to the admission to the German hospitals. The infection and colonization pressure in the conflict regions of the Eastern Ukraine with ABC of low clonal diversity is considerable. Respective infection risks have to be considered in case of battle-related injuries in these regions. The low number of local clones makes any molecular exclusion of transmission events difficult. PMID:27429793

  17. Early detection of metallo-β-lactamase NDM-1- and OXA-23 carbapenemase-producing Acinetobacter baumannii in Libyan hospitals.

    Science.gov (United States)

    Mathlouthi, Najla; El Salabi, Allaaeddin Ali; Ben Jomàa-Jemili, Mariem; Bakour, Sofiane; Al-Bayssari, Charbel; Zorgani, Abdulaziz A; Kraiema, Abdulmajeed; Elahmer, Omar; Okdah, Liliane; Rolain, Jean-Marc; Chouchani, Chedly

    2016-07-01

    Acinetobacter baumannii is an opportunistic pathogen causing various nosocomial infections. The aim of this study was to characterise the molecular support of carbapenem-resistant A. baumannii clinical isolates recovered from two Libyan hospitals. Bacterial isolates were identified by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF/MS). Antibiotic susceptibility testing was performed using disk diffusion and Etest methods, and carbapenem resistance determinants were studied by PCR amplification and sequencing. Multilocus sequence typing (MLST) was performed for typing of the isolates. All 36 imipenem-resistant isolates tested were identified as A. baumannii. The blaOXA-23 gene was detected in 29 strains (80.6%). The metallo-β-lactamase blaNDM-1 gene was detected in eight isolates (22.2%), showing dissemination of multidrug-resistant (MDR) A. baumannii in Tripoli Medical Center and Burn and Plastic Surgery Hospital in Libya, including one isolate that co-expressed the blaOXA-23 gene. MLST revealed several sequence types (STs). Imipenem-resistant A. baumannii ST2 was the predominant clone (16/36; 44.4%). This study shows that NDM-1 and OXA-23 contribute to antibiotic resistance in Libyan hospitals and represents the first incidence of the association of these two carbapenemases in an autochthonous MDR A. baumannii isolated from patients in Libya, indicating that there is a longstanding infection control problem in these hospitals. PMID:27216382

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

    Directory of Open Access Journals (Sweden)

    Saghi

    2015-02-01

    Full Text Available Background Infection due to Acinetobacter baumannii has become a significant challenge to modern healthcare systems. The rapid emergence and global dissemination of A. baumannii as a major nosocomial pathogen is remarkable and it demonstrates its successful adaptation to the 21st century hospital environment. Recent studies have discussed about essential oil of Origanum vulgare against a range of bacteria, including various species of Staphylococcus, Pseudomonas, Bacillus and Escherichia coli. Objectives The present study aimed to investigate the inhibitory effects O. vulgare essence against multidrug-resistant (MDR strains of A. baumannii from selected hospitals in Tehran, Iran. Materials and Methods This oil was obtained using the hydrodistillation method and analyzed by gas chromatography mass spectrography (GC/MS. The antimicrobial activity against MDR isolates was achieved using disc diffusion method and macro-broth dilution assay. Results Analysis of the essential oil revealed the presence of pulegone (68.59% piperitone (7.8%, piperitenone (7.8%, 1, 8-cineole (1.3%, and carvacrol (1.6% as the major components. The results showed a significant activity against MDR A. baumannii with inhibition zones and minimal inhibitory concentration values in the ranges of 7-15 mm and 20-35 µL/mL respectively. Conclusions This investigation showed that the essence oil of O. vulgare had a potent antimicrobial activity against MDR A. baumannii. Further research is required to evaluate the practical values of therapeutic applications.

  19. In vitro activities of nontraditional antimicrobials against multiresistant Acinetobacter baumannii strains isolated in an intensive care unit outbreak.

    Science.gov (United States)

    Appleman, M D; Belzberg, H; Citron, D M; Heseltine, P N; Yellin, A E; Murray, J; Berne, T V

    2000-04-01

    Fifteen multiresistant Acinetobacter baumannii isolates from patients in intensive care units and 14 nonoutbreak strains were tested to determine in vitro activities of nontraditional antimicrobials, including cefepime, meropenem, netilmicin, azithromycin, doxycycline, rifampin, sulbactam, and trovafloxacin. The latter five drugs were further tested against four of the strains for bactericidal or bacteriostatic activity by performing kill-curve studies at 0.5, 1, 2, and 4 times their MICs. In addition, novel combinations of drugs with sulbactam were examined for synergistic interactions by using a checkerboard configuration. MICs at which 90% of the isolates tested were inhibited for antimicrobials showing activity against the multiresistant A. baumannii strains were as follows (in parentheses): doxycycline (1 microg/ml), azithromycin (4 microg/ml), netilmicin (1 microg/ml), rifampin (8 microg/ml), polymyxin (0.8 U/ml), meropenem (4 microg/ml), trovafloxacin (4 microg/ml), and sulbactam (8 microg/ml). In the kill-curve studies, azithromycin and rifampin were rapidly bactericidal while sulbactam was more slowly bactericidal. Trovafloxacin and doxycycline were bacteriostatic. None of the antimicrobials tested were bactericidal against all strains tested. The synergy studies demonstrated that the combinations of sulbactam with azithromycin, rifampin, doxycycline, or trovafloxacin were generally additive or indifferent.

  20. Predictive value of Sp1/Sp3/FLIP signature for prostate cancer recurrence.

    Directory of Open Access Journals (Sweden)

    Roble G Bedolla

    Full Text Available Prediction of prostate cancer prognosis is challenging and predictive biomarkers of recurrence remain elusive. Although prostate specific antigen (PSA has high sensitivity (90% at a PSA level of 4.0 ng/mL, its low specificity leads to many false positive results and considerable overtreatment of patients and its performance at lower ranges is poor. Given the histopathological and molecular heterogeneity of prostate cancer, we propose that a panel of markers will be a better tool than a single marker. We tested a panel of markers composed of the anti-apoptotic protein FLIP and its transcriptional regulators Sp1 and Sp3 using prostate tissues from 64 patients with recurrent and non-recurrent cancer who underwent radical prostatectomy as primary treatment for prostate cancer and were followed with PSA measurements for at least 5 years. Immunohistochemical staining for Sp1, Sp3, and FLIP was performed on these tissues and scored based on the proportion and intensity of staining. The predictive value of the FLIP/Sp1/Sp3 signature for clinical outcome (recurrence vs. non-recurrence was explored with logistic regression, and combinations of FLIP/Sp1/Sp3 and Gleason score were analyzed with a stepwise (backward and forward logistic model. The discrimination of the markers was identified by sensitivity-specificity analysis and the diagnostic value of FLIP/Sp1/Sp3 was determined using area under the curve (AUC for receiver operator characteristic curves. The AUCs for FLIP, Sp1, Sp3, and Gleason score for predicting PSA failure and non-failure were 0.71, 0.66, 0.68, and 0.76, respectively. However, this increased to 0.93 when combined. Thus, the "biomarker signature" of FLIP/Sp1/Sp3 combined with Gleason score predicted disease recurrence and stratified patients who are likely to benefit from more aggressive treatment.

  1. PENGARUH FILTRAT CENDAWAN Aspergillus sp. DAN Fusarium sp. TERHADAP VIABILITAS BENIH DAN PERTUMBUHAN BIBIT SENGON (Paraserianthes falcataria)

    OpenAIRE

    Naning Yuniarti; Tati Suharti; Yulianti Bramasto

    2013-01-01

    Fungi are one of the main causes of damage to seeds. Fungi can be a pathogen or saprophyte such as Aspergillus sp. and Fusarium sp. The purpose of this study was to determine the effects of filtrate fungus Aspergillus sp and Fusarium sp on seed viability and seedling growth performance of Sengon (Paraserianthes falcataria). The experiment design used was the Completely Randomized Design (CRD), with treatment: control, filtrate of Aspergillus sp and Fusarium sp filtrate. Each treatment was rep...

  2. Fresh Water Cyanobacteria Geitlerinema sp. CCC728 and Arthrospira sp. CCC729 as an Anticancer Drug Resource

    OpenAIRE

    Akanksha Srivastava; Ratnakar Tiwari; Vikas Srivastava; Tej Bali Singh; Ravi Kumar Asthana

    2015-01-01

    An increasing number of cancer patients worldwide, especially in third world countries, have raised concern to explore natural drug resources, such as the less explored fresh water filamentous cyanobacteria. Six strains of cyanobacteria (Phormidium sp. CCC727, Geitlerinema sp. CCC728, Arthrospira sp. CCC729, Phormidium sp. CCC731, Phormidium sp. CCC730, and Leptolyngbya sp. CCC732) were isolated (paddy fields and ponds in the Banaras Hindu University, campus) and five strains screened for ant...

  3. Clinical analysis of 74 cases of bloodstream infections caused by multidrug-resist-ant Acinetobacter%多重耐药不动杆菌属血流感染74例临床分析

    Institute of Scientific and Technical Information of China (English)

    邹颖; 徐晓刚; 郭庆兰; 李光辉

    2014-01-01

    Objective To study the clinical characteristics,antimicrobial restistance of bloodstream infections (bacteremia) caused by multidrug-resistant Acinetobacter and analyze the outcomes of antibacterial therapy.Methods The clinical data were reviewed retrospectively for 74 patients with bloodstream infection caused by multidrug-resistant Acinetobacter who were trea-ted in HuaShan hospital from January 2005 to December 2011 .Results During the 6-year period,74 patients were diagnosed with multidrug-resistant Acinetobacter bacteremia,73 of which were nosocomial infections.The remaining one was community-acquired. Primary bloodstream infection accounted for 51 .4% (38/74),and secondary infection 48.6% (36/74), mainly secondary to pulmonary infections (23.0%,17/74). Solid tumor was the most common underlying disease (24.3%,18/74).Prior corticosteroid therapy,indwelling deep venous catheter,surgery and invasive procedures were predisposing factors of bacteremia. Acinetobacter-related bloodstream infections were associated with higher white blood cell count,increased neutrophil percentage,higher APACHE II score and lower serum albumin level.The bloodstream infection was caused by Acinetobacter baumannii in 65 pa-tients,Acinetobacter lwoffi in 7 patients,both Acinetobacter baumannii and Acinetobacter junii in one patient.The all-cause mortality rate was 27.0% (20/74).In vitro susceptibility testing showed that 20.0% (15/75 )of the Acinetobacter isolates were resistant to cefoperazone-sulbactam,which was the lowest among all the antibiotics tested.About 40.0% to 42.7% of the isolates were resistant to carbapenems.The outcome was related to the antimicrobial restistance.Carbapenem non-suscepti-ble Acinetobacter was associated with poorer outcome compared with carbapenem-susceptible Acinetobacter (mortality 46.9%vs 11 .9%,P <0.05 ).Cefoperazone-sulbactam non-susceptible Acinetobacter was also associated with poorer outcome com-pared with cefoperazone-sulbactam susceptible

  4. Coexistence of Extended Spectrum Beta-Lactamases, AmpC Beta-Lactamases and Metallo-Beta-Lactamases in Acinetobacter baumannii from burns patients: a report from a tertiary care centre of India.

    Science.gov (United States)

    Gupta, V; Garg, R; Garg, S; Chander, J; Attri, A K

    2013-12-31

    Multidrug-resistant Acinetobacter baumanii is a major pathogen encountered in pyogenic infections, especially from burns patients in hospital settings. Often there is also coexistence of multiple beta-lactamase enzymes responsible for beta-lactam resistance in a single isolate, which further complicates treatment options. We conducted a study on burn wound pus samples obtained from the burns unit of our hospital. Phenotypic tests were used to determine the Extended Spectrum Beta-Lactamase, AmpC Beta-Lactamase and Metallo-Beta-Lactamase producing status of the isolates. Almost half of the samples from the burn wounds yielded Acinetobacter baumanii as the predominant pathogen (54.05%). Coexistence of the three resistance mechanisms was seen in 25 of the 100 (25%) isolates of Acinetobacter baumanii. This study emphasizes the need for the detection of isolates that produce these enzymes to avoid therapeutic failures and nosocomial outbreaks. PMID:24799848

  5. Safradan İzole Edilen Campylobacter Sp.

    OpenAIRE

    Yorgancıgil, Birdal; Tezeren, Deniz; Balaban, Neriman; Terzioğlu, Serdar; Öztürk, Süheyla

    2009-01-01

    SüleymanDemirel Üniversitesi TIP FAKÜLTESİ DERGİSİ: 1997 Haziran; 4(3) Safradan İzole Edilen Campylobacter Sp. Birdal YORGANCIGİL Deniz TEZEREN Neriman BALABAN Serdar TERZlOĞLU Süheyla ÖZTÜRK Özet Campylobacter sp. 'in neden olduğu, gastrointestinal traktüs haricindeki lokal veya sistemik infeksiyon vakaları oldukça azdır. Bu çalışmada safradan izole edilen bir Campylobacter sp. olgusu incelenmiştir. Ankara Numune Hastanesi Cerrahi Kliniğinde koles...

  6. Evaluation of the antibacterial effect of Echium amoenum Fisch. et Mey. against multidrug resistant Acinetobacter baumannii strains isolated from burn wound infection

    Directory of Open Access Journals (Sweden)

    Mandana Sabour

    2015-02-01

    Full Text Available Introduction and aims: Acinetobacter baumannii in recent decay has become an increasing concern in hospitals for its ability to acquire antibiotic resistance determinants rapidly and becoming resistant to almost all of the antibiotic classes. Borage (Echium amoenum  Fisch. et Mey, is a wild annual plant of Boraginaceae family, grows in northern mountains of Iran and has largely been used by Iranian folk as a mood enhancer, anti anxiolytic, anti inflammatory, a laxative, an emollients and also it has been used  for treatment of infectious diseases. So, in this study the methanolic extract of dried flowers of Echium amoenom were tested against the isolates of Acinetobacter baumannii from wound of burn patients.Materials and methods: 30 drug resistant Acinetobacter baumannii strains which were isolated from burn wounds at the Motahari hospital of Tehran were selected. Antibacterial activity of the methanolic extract was evaluated by the disc diffusion method based on CLSI protocol 2012Results: The mean diameter of the inhibition zone for different extracts  were; 9.967±6.139 mm at the concentration of 4000 ppm, at the concentration of 400 ppm 13.37±5.45 mm, 13.53±5.49 mm at the concentration of 200 ppm, 14.77±5.17mm  at the concentration of 100 ppm and 14.13±5.7806mm  at the concentration of 50 ppm.Conclusion: clinical strains of the A. baumannii were almost highly resistant to imipenem which is the common choice of antibiotic therapy in the hospitals. Due to the calculated p value ≤ 0.05 in this study, it can say that borage extract can be as good as or even better than the imipenem which is used in the hospitals now.

  7. 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.

  8. Uji Efektifitas Jamur Antagonis Trichoderma sp. Dan Gliocladium sp. Untuk Mengendalikan Penyakit Layu Fusarium

    OpenAIRE

    Nasution, Rima Yunisa

    2015-01-01

    Rima Yunisa Nasution. 2014. Effectiveness test on antagonist fungi Trichoderma sp. and Gliocladium Sp. to control fusarium disease (Fusarium oxysporum F.sp capsici) for chilli crop (Capsicum Annuum L.) at screen house. Supervised by Lahmuddin Lubis and Hassanuddin. The goal of the research is to examine antagonist fungi Trichoderma and Gliocladium virens towards F. Oxysporum that lead the fusarium disease for chilli crop at screen house. The research was conducted at Plant Dise...

  9. Metabolites from marine fungus Aspergillus sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Rajmanickam, R.; DeSouza, L.

    Chemical examination of a methanolic extract of the marine fungus, Aspergillus sp., isolated from marine grass environment, yielded a steroid, ergosterol peroxide (1), and a mixture of known glyceride esters (2,3) of unsaturated fatty acids...

  10. Tubulinosema sp. Microsporidian Myositis in Immunosuppressed Patient

    OpenAIRE

    Choudhary, Maria M.; Metcalfe, Maureen G.; Arrambide, Kathryn; Bern, Caryn; Visvesvara, Govinda S.; Pieniazek, Norman J.; Bandea, Rebecca D.; Deleon-Carnes, Marlene; Adem, Patricia; Choudhary, Moaz M.; Zaki, Sherif R.; Saeed, Musab U.

    2011-01-01

    The Phylum Microsporidia comprises >1,200 species, only 15 of which are known to infect humans, including the genera Trachipleistophora, Pleistophora, and Brachiola. We report an infection by Tubulinosema sp. in an immunosuppressed patient.

  11. Chemical shift assignments and secondary structure prediction of the C-terminal domain of the response regulator BfmR from Acinetobacter baumannii.

    Science.gov (United States)

    Olson, Andrew L; Thompson, Richele J; Melander, Christian; Cavanagh, John

    2014-04-01

    Acinetobacter baumannii is a Gram-negative pathogen responsible for severe nocosomial infections by forming biofilms in healthcare environments. The two-domain response regulator BfmR has been shown to be the master controller for biofilm formation. Inactivation of BfmR resulted in an abolition of pili production and consequently biofilm creation. Here we report backbone and sidechain resonance assignments and secondary structure prediction for the C-terminal domain of BfmR (residues 130-238) from A. baumannii.

  12. Rgional Difference of Drug Resistance of Acinetobacter Baumanii in Guangxi%广西鲍曼不动杆菌耐药性的地区差异

    Institute of Scientific and Technical Information of China (English)

    于虹

    2016-01-01

    Objective To study the reginal difference of drug resistance situation of acinetobacter baumanii in Guangxi. Methods The drug resistance rate of 1243 strains of acinetobacter baumanii isolated from clinical specimens in some grade AAA hospital in Guangxi to common antibiotics was counted and analyzed. Results In addition to cefoperazone/sulbactam in 2014, the drug resistance rates of acinetobacter baumanii to the other antimicrobial drugs were obviously at a high level, a-mong them, the resistance rate to aztreonam, piperacillin and ciprofloxacin and carbapenem (imipenem, meropenem) were respectively 100%, nearly 90% and more than 80%, which was higher than the drug resistance monitoring data of China CHINET. Conclusion The drug situation of acinetobacter baumanii in Guangxi was obviously higher than the national level with regional difference, which should be paid great attention.%目的:探讨广西地区鲍曼不动杆菌耐药形势的地区差异性。方法对广西某大型三甲医院2014年临床标本分离出的1243株鲍曼不动杆菌对常用抗菌素的耐药率进行统计和分析。结果2014年除头胞哌酮/舒巴坦外,鲍曼不动杆菌对其他监测的抗菌药物耐药率均明显处于高水平,其中对氨曲南耐药率为100%,对哌拉西林及环丙沙星耐药率已接近90%,对碳青霉烯类药物(亚胺培南、美罗培南)耐药率已大于80%,并高于中国CHINET耐药监测数据。结论广西地区鲍曼不动杆菌耐药形势明显高于全国水平,具有地方差异性,应引起高度重视。

  13. Carboxylation and Decarboxylation of Active Site Lys 84 Controls the Activity of OXA-24 β-Lactamase of Acinetobacter baumannii: Raman Crystallographic and Solution Evidence

    OpenAIRE

    Che, Tao; Robert A Bonomo; Shanmugam, Sivaprakash; Bethel, Christopher R.; Pusztai-Carey, Marianne; Buynak, John D.; Carey, Paul R.

    2012-01-01

    The class D β-lactamases are characterized by the presence of a carboxylated lysine in the active site that participates in catalysis. Found in Acinetobacter baumannii, OXA-24 is a class D carbapenem hydrolyzing enzyme that exhibits resistance to most available β-lactamase inhibitors. In this study, the reaction between a 6-alkylidiene penam sulfone inhibitor, SA-1-204, in single crystals of OXA-24 is followed by Raman microscopy. Details of its reaction with SA-1-204 provide insight into the...

  14. First Description of Two Sequence Type 2 Acinetobacter baumannii Isolates Carrying OXA-23 Carbapenemase in Pagellus acarne Fished from the Mediterranean Sea near Bejaia, Algeria.

    Science.gov (United States)

    Brahmi, Soumia; Touati, Abdelaziz; Cadière, Axelle; Djahmi, Nassima; Pantel, Alix; Sotto, Albert; Lavigne, Jean-Philippe; Dunyach-Remy, Catherine

    2016-04-01

    To determine the occurrence of carbapenem-resistantAcinetobacter baumanniiin fish fished from the Mediterranean Sea near the Bejaia coast (Algeria), we studied 300 gills and gut samples that had been randomly and prospectively collected during 1 year. After screening on selective agar media, using PCR arrays and whole-genome sequencing, we identified for the first time two OXA-23-producingA. baumanniistrains belonging to the widespread sequence type 2 (ST2)/international clone II and harboring aminoglycoside-modifying enzymes [aac(6')-Ib andaac(3')-I genes]. PMID:26787693

  15. Synergy between Colistin and the Signal Peptidase Inhibitor MD3 Is Dependent on the Mechanism of Colistin Resistance in Acinetobacter baumannii.

    Science.gov (United States)

    Martínez-Guitián, Marta; Vázquez-Ucha, Juan C; Odingo, Joshua; Parish, Tanya; Poza, Margarita; Waite, Richard D; Bou, German; Wareham, David W; Beceiro, Alejandro

    2016-07-01

    Synergy between colistin and the signal peptidase inhibitor MD3 was tested against isogenic mutants and clinical pairs of Acinetobacter baumannii isolates. Checkerboard assays and growth curves showed synergy against both colistin-susceptible strains (fractional inhibitory concentration index [FICindex] = 0.13 to 0.24) and colistin-resistant strains with mutations in pmrB and phosphoethanolamine modification of lipid A (FICindex = 0.14 to 0.25) but not against colistin-resistant Δlpx strains with loss of lipopolysaccharide (FICindex = 0.75 to 1). A colistin/MD3 combination would need to be targeted to strains with specific colistin resistance mechanisms. PMID:27139471

  16. Synthesis, optimization, and characterization of silver nanoparticles from Acinetobacter calcoaceticus and their enhanced antibacterial activity when combined with antibiotics

    Directory of Open Access Journals (Sweden)

    Singh R

    2013-11-01

    Full Text Available Richa Singh,1 Priyanka Wagh,1 Sweety Wadhwani,1 Sharvari Gaidhani,2 Avinash Kumbhar,3 Jayesh Bellare,4 Balu Ananda Chopade1 1Department of Microbiology, University of Pune, Pune, Maharashtra, India; 2Institute of Bioinformatics and Biotechnology, University of Pune, Pune, Maharashtra, India; 3Department of Chemistry, University of Pune, Pune, Maharashtra, India; 4Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India Background: The development of nontoxic methods of synthesizing nanoparticles is a major step in nanotechnology to allow their application in nanomedicine. The present study aims to biosynthesize silver nanoparticles (AgNPs using a cell-free extract of Acinetobacter spp. and evaluate their antibacterial activity. Methods: Eighteen strains of Acinetobacter were screened for AgNP synthesis. AgNPs were characterized using various techniques. Reaction parameters were optimized, and their effect on the morphology of AgNPs was studied. The synergistic potential of AgNPs on 14 antibiotics against seven pathogens was determined by disc-diffusion, broth-microdilution, and minimum bactericidal concentration assays. The efficacy of AgNPs was evaluated as per the minimum inhibitory concentration (MIC breakpoints of the Clinical and Laboratory Standards Institute (CLSI guidelines. Results: Only A. calcoaceticus LRVP54 produced AgNPs within 24 hours. Monodisperse spherical nanoparticles of 8–12 nm were obtained with 0.7 mM silver nitrate at 70°C. During optimization, a blue-shift in ultraviolet-visible spectra was seen. X-ray diffraction data and lattice fringes (d =0.23 nm observed under high-resolution transmission electron microscope confirmed the crystallinity of AgNPs. These AgNPs were found to be more effective against Gram-negative compared with Gram-positive microorganisms. Overall, AgNPs showed the highest synergy with vancomycin in the disc-diffusion assay. For Enterobacter

  17. Silencing the SpMPK1, SpMPK2, and SpMPK3 Genes in Tomato Reduces Abscisic Acid—Mediated Drought Tolerance

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    Yan Liang

    2013-11-01

    Full Text Available Drought is a major threat to agriculture production worldwide. Mitogen-activated protein kinases (MAPKs play a pivotal role in sensing and converting stress signals into appropriate responses so that plants can adapt and survive. To examine the function of MAPKs in the drought tolerance of tomato plants, we silenced the SpMPK1, SpMPK2, and SpMPK3 genes in wild-type plants using the virus-induced gene silencing (VIGS method. The results indicate that silencing the individual genes or co-silencing SpMPK1, SpMPK2, and SpMPK3 reduced the drought tolerance of tomato plants by varying degrees. Co-silencing SpMPK1 and SpMPK2 impaired abscisic acid (ABA-induced and hydrogen peroxide (H2O2-induced stomatal closure and enhanced ABA-induced H2O2 production. Similar results were observed when silencing SpMPK3 alone, but not when SpMPK1 and SpMPK2 were individually silenced. These data suggest that the functions of SpMPK1 and SpMPK2 are redundant, and they overlap with that of SpMPK3 in drought stress signaling pathways. In addition, we found that SpMPK3 may regulate H2O2 levels by mediating the expression of CAT1. Hence, SpMPK1, SpMPK2, and SpMPK3 may play crucial roles in enhancing tomato plants’ drought tolerance by influencing stomatal activity and H2O2 production via the ABA-H2O2 pathway.

  18. Cloning of rat sp56, the homologue of mouse sperm ZP3 receptor-sp56

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Mouse sp56 is considered as one of the candidates for mouse zona pellucida 3 (mZP3) receptor. Up to date, its homologue has only been cloned from guinea pig, namely AM67. Based on the cDNA sequence of mouse sp56, we designed a pair of primer to amplify its homologue from rat testis cDNA. Using RT-PCR,two fragments of 743 bp and 938 bp were amplified. The PCR products show very high homology to mouse sp56. However, the 743 bp product completely lacks one of the seven Sushi domains of mouse sp56. Using the 743 bp product as the probe to detect the expression profile of sp56 in rat tissues, Northern blot shows that a ~2.0 kb mRNA expresses specifically in testis. Employed the RACE method, two full cDNA sequences of rat sp56 were obtained. A Mr ~42 KD band was detected in denatured and non-reducing protein sample of rat testis and sperm with anti-mouse sp56 monoclonal antibody by Western blot method. Rat sp56was localized on rat sperm head by the indirect immunofiuorescence method. Rat sp56 immunoreactivitywas detected from the early pachytene spermatocytes and throughout the spermatogenesis. Its cloning willfurther our understanding of the mechanism of the sperm-egg recognition and binding.

  19. The C-terminal domain of 4-hydroxyphenylacetate 3-hydroxylase from Acinetobacter baumannii is an autoinhibitory domain.

    Science.gov (United States)

    Phongsak, Thanawat; Sucharitakul, Jeerus; Thotsaporn, Kittisak; Oonanant, Worrapoj; Yuvaniyama, Jirundon; Svasti, Jisnuson; Ballou, David P; Chaiyen, Pimchai

    2012-07-27

    p-Hydroxyphenylacetate (HPA) 3-hydroxylase from Acinetobacter baumannii consists of a reductase component (C(1)) and an oxygenase component (C(2)). C(1) catalyzes the reduction of FMN by NADH to provide FMNH(-) as a substrate for C(2). The rate of reduction of flavin is enhanced ∼20-fold by binding HPA. The N-terminal domain of C(1) is homologous to other flavin reductases, whereas the C-terminal domain (residues 192-315) is similar to MarR, a repressor protein involved in bacterial antibiotic resistance. In this study, three forms of truncated C(1) variants and single site mutation variants of residues Arg-21, Phe-216, Arg-217, Ile-246, and Arg-247 were constructed to investigate the role of the C-terminal domain in regulating C(1). In the absence of HPA, the C(1) variant in which residues 179-315 were removed (t178C(1)) was reduced by NADH and released FMNH(-) at the same rates as wild-type enzyme carries out these functions in the presence of HPA. In contrast, variants with residues 231-315 removed behaved similarly to the wild-type enzyme. Thus, residues 179-230 are involved in repressing the production of FMNH(-) in the absence of HPA. These results are consistent with the C-terminal domain in the wild-type enzyme being an autoinhibitory domain that upon binding the effector HPA undergoes conformational changes to allow faster flavin reduction and release. Most of the single site variants investigated had catalytic properties similar to those of the wild-type enzyme except for the F216A variant, which had a rate of reduction that was not stimulated by HPA. F216A could be involved with HPA binding or in the required conformational change for stimulation of flavin reduction by HPA. PMID:22661720

  20. Risk factors and outcomes of Stenotrophomonas maltophilia bacteraemia: a comparison with bacteraemia caused by Pseudomonas aeruginosa and Acinetobacter species.

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    Go Hotta

    Full Text Available Stenotrophomonas maltophilia (SM is an important nosocomial pathogen that exhibits intrinsic resistance to various antimicrobial agents. However, the risk factors for SM bacteraemia have not been sufficiently evaluated. From January 2005 to September 2012, we retrospectively compared the clinical backgrounds and outcomes of SM bacteraemic patients (SM group with those of bacteraemic patients due to Pseudomonas aeruginosa (PA group or Acinetobacter species (AC group. DNA genotyping of the SM isolates using the Diversilab system was performed to investigate the genetic relationships among the isolates. The SM, PA, and AC groups included 54, 167, and 69 patients, respectively. Nine of 17 patients in the SM group receiving trimethoprim-sulfamethoxazole prophylaxis developed SM bacteraemia. Independent risk factors for SM bacteraemia were the use of carbapenems and antipseudomonal cephalosporins and SM isolation within 30 days prior to the onset of bacteraemia. Earlier SM isolation was observed in 32 of 48 patients (66.7% with SM bacteraemia who underwent clinical microbiological examinations. Of these 32 patients, 15 patients (46.9% had the same focus of bacteraemia as was found in the previous isolation site. The 30-day all-cause mortality rate among the SM group (33.3% was higher than that of the PA group (21.5%, p = 0.080 and the AC group (17.3%, p = 0.041. The independent factor that was associated with 30-day mortality was the SOFA score. DNA genotyping of SM isolates and epidemiological data suggested that no outbreak had occurred. SM bacteraemia was associated with high mortality and should be considered in patients with recent use of broad-spectrum antibiotics or in patients with recent isolation of the organism.

  1. Polyvinyl alcohol nanofiber formulation of the designer antimicrobial peptide APO sterilizes Acinetobacter baumannii-infected skin wounds in mice.

    Science.gov (United States)

    Sebe, Istvan; Ostorhazi, Eszter; Fekete, Aron; Kovacs, Krisztian N; Zelko, Romana; Kovalszky, Ilona; Li, Wenyi; Wade, John D; Szabo, Dora; Otvos, Laszlo

    2016-01-01

    Native and designer cationic antimicrobial peptides are increasingly acknowledged as host defense molecules rather than true antimicrobials. Due to their ability to activate the innate immune system, these structures are used to treat uninfected and bacterially-infected wounds, including those harboring Acinetobacter baumannii. Previously we documented that when administered intramuscularly or topically in liquid formulations, the proline-rich host defense peptide dimer A3-APO accelerates uninfected wound re-epithelization and eliminates systemic and local A. baumannii, methicillin-resistant Staphylococcus aureus and other pathogen load from infected lesions better than conventional antibiotics. In the current study we sought to produce and characterize a novel delivery system, suitable for immediate and convenient application in non-hospital environments. The APO monomer was incorporated into polyvinyl alcohol nanofibers and the complex was polymerized into a solid patch dressing. Mice were subjected to skin abrasion where the wounds were either left uninfected or were inoculated with a near lethal dose of multidrug resistant A. baumannii strain. Analyzed after 3 days, APO monomer-containing patches improved wound appearance significantly better than polymer patches without antibiotics. When compared to colistin, the APO patches accelerated wound healing, and statistically significantly reduced wound size and wound bacterial load. The in vivo antimicrobial effect was more extensive than after intramuscular administration of the peptide drug, by using only one tenth of the active pharmaceutical ingredient. These data suggest that the APO monomer-impregnated nanofiber dressing can be developed as an economical first-line treatment option to skin injuries in general and battlefield burn and blast injuries in particular. PMID:26319645

  2. Reprint of: Nitric oxide-releasing polysaccharide derivative exhibits 8-log reduction against Escherichia coli, Acinetobacter baumannii and Staphylococcus aureus.

    Science.gov (United States)

    Pegalajar-Jurado, Adoracion; Wold, Kathryn A; Joslin, Jessica M; Neufeld, Bella H; Arabea, Kristin A; Suazo, Lucas A; McDaniel, Stephen L; Bowen, Richard A; Reynolds, Melissa M

    2015-12-28

    Health-care associated infections (HAIs) and the increasing number of antibiotic-resistant bacteria strains remain significant public health threats worldwide. Although the number of HAIs has decreased by using improved sterilization protocols, the cost related to HAIs is still quantified in billions of dollars. Furthermore, the development of multi-drug resistant strains is increasing exponentially, demonstrating that current treatments are inefficient. Thus, the quest for new methods to eradicate bacterial infection is increasingly important in antimicrobial, drug delivery and biomaterials research. Herein, the bactericidal activity of a water-soluble NO-releasing polysaccharide derivative was evaluated in nutrient broth media against three bacteria strains that are commonly responsible for HAIs. Data confirmed that this NO-releasing polysaccharide derivative induced an 8-log reduction in bacterial growth after 24h for Escherichia coli, Acinetobacter baumannii and Staphylococcus aureus. Additionally, the absence of bacteria after 72 h of exposure to NO illustrates the inability of the bacteria to recover and the prevention of biofilm formation. The presented 8-log reduction in bacterial survival after 24h is among the highest reduction reported for NO delivery systems to date, and reaches the desired standard for industrially-relevant reduction. More specifically, this system represents the only water-soluble antimicrobial to reach such a significant bacterial reduction in nutrient rich media, wherein experimental conditions more closely mimic the in vivo environment than those in previous reports. Furthermore, the absence of bacterial activity after 72 h and the versatility of using a water-soluble compound suggest that this NO-releasing polysaccharide derivative is a promising route for treating HAIs.

  3. Individual or Combined Effects of Meropenem, Imipenem, Sulbactam, Colistin, and Tigecycline on Biofilm-Embedded Acinetobacter baumannii and Biofilm Architecture.

    Science.gov (United States)

    Wang, Yung-Chih; Kuo, Shu-Chen; Yang, Ya-Sung; Lee, Yi-Tzu; Chiu, Chun-Hsiang; Chuang, Ming-Fen; Lin, Jung-Chung; Chang, Feng-Yee; Chen, Te-Li

    2016-08-01

    Acinetobacter baumannii biofilms are difficult to eradicate. We investigated the effects of meropenem (2 mg/liter), imipenem (2 mg/liter), sulbactam (4 mg/liter), colistin (2 mg/liter), and tigecycline (2 mg/liter), alone or in combination, on biofilm-embedded carbapenem-resistant and carbapenem-susceptible A. baumannii (CRAb and CSAb, respectively) cells, as well as on the architecture of the biofilms. A. baumannii ATCC 15151 (Ab15151) and its OXA-82-overproducing transformant, along with two clinical CSAb and two clinical CRAb isolates of differing clonalities, were used. The minimal bactericidal concentrations for biofilm-embedded cells of the six tested isolates were >50-fold those of their planktonic cells. When used individually, meropenem exhibited a higher killing effect than the other four antimicrobials on biofilm-embedded CSAb cells in the colony biofilm assay. For two clinical CRAb isolates, meropenem plus sulbactam or sulbactam plus tigecycline showed >100-fold the bactericidal effect exhibited by these agents used alone after 48 h of treatment. The effect of antimicrobials on the architecture of Ab15151 biofilm emitting green fluorescence was determined by confocal laser scanning microscopy using COMSTAT software. Significant decreases in the maximum biofilm thickness were observed after exposure to meropenem and imipenem. Meropenem plus sulbactam significantly decreased the biomass and mean thickness and increased the roughness coefficient of biofilms, but sulbactam plus tigecycline only decreased the maximum and mean biofilm thickness compared to any of these agents used alone. Meropenem was active against biofilm-embedded CSAb, whereas meropenem plus sulbactam exhibited synergism against biofilm-embedded CRAb and caused significantly more damage to the biofilm architecture than did any of the agents used alone. PMID:27216052

  4. Antibiotic susceptibility and molecular epidemiology of Acinetobacter calcoaceticus–baumannii complex strains isolated from a referral hospital in northern Vietnam

    Science.gov (United States)

    Van, Trang Dinh; Dinh, Quynh-Dao; Vu, Phu Dinh; Nguyen, Trung Vu; Pham, Ca Van; Dao, Trinh Tuyet; Phung, Cam Dac; Hoang, Ha Thu Thi; Tang, Nga Thi; Do, Nga Thuy; Nguyen, Kinh Van; Wertheim, Heiman

    2014-01-01

    Acinetobacter calcoaceticus–baumannii complex is a common cause of hospital-acquired infections (HAIs) globally, remarkable for its high rate of antibiotic resistance, including to carbapenems. There are few data on the resistance of A. baumannii in Vietnam, which are essential for developing evidence-based treatment guidelines for HAIs. Antibiotic susceptibility testing was conducted by VITEK®2, and pulsed-field gel electrophoresis (PFGE) was performed on 66 clinical A. baumannii complex isolates recovered during 2009 at the National Hospital of Tropical Diseases (NHTD), a referral hospital in Hanoi, Vietnam. Basic demographic and clinical data were collected and analysed using descriptive statistics. Most isolates came from lower respiratory tract specimens (59; 89.4%) from intensive care unit (ICU) patients [64/65 (98.5%) with available data] who had been admitted to NHTD for ≥2 days [42/46 (91.3%) with available data]. More than 90% of the isolates were resistant to the tested β-lactamase/β-lactamase inhibitors, cephalosporins, carbapenems, fluoroquinolones and trimethoprim/sulfamethoxazole. Moreover, 25.4% (16/63) were resistant to all tested β-lactams, quinolones and aminoglycosides. All isolates remained sensitive to colistin and 58.7% were susceptible to tigecycline. Of the 66 isolates, 49 could be classified into eight PFGE types (A–H). Every PFGE type, except D, had cluster(s) of three or more isolates with a temporal relationship. In conclusion, these data suggest a significant rise in A. baumannii antibiotic resistance in Vietnam. Clustering within PFGE types supports cross-transmission of A. baumannii within the ICU at NHTD. Increased research and resources in optimising treatment, infection control and antibiotic stewardship are needed. PMID:25540720

  5. Growth retardation, reduced invasiveness, and impaired colistin-mediated cell death associated with colistin resistance development in Acinetobacter baumannii.

    Science.gov (United States)

    Pournaras, Spyros; Poulou, Aggeliki; Dafopoulou, Konstantina; Chabane, Yassine Nait; Kristo, Ioulia; Makris, Demosthenes; Hardouin, Julie; Cosette, Pascal; Tsakris, Athanassios; Dé, Emmanuelle

    2014-01-01

    Two colistin-susceptible/colistin-resistant (Col(s)/Col(r)) pairs of Acinetobacter baumannii strains assigned to international clone 2, which is prevalent worldwide, were sequentially recovered from two patients after prolonged colistin administration. Compared with the respective Col(s) isolates (Ab248 and Ab299, both having a colistin MIC of 0.5 μg/ml), both Col(r) isolates (Ab249 and Ab347, with colistin MICs of 128 and 32 μg/ml, respectively) significantly overexpressed pmrCAB genes, had single-amino-acid shifts in the PmrB protein, and exhibited significantly slower growth. The Col(r) isolate Ab347, tested by proteomic analysis in comparison with its Col(s) counterpart Ab299, underexpressed the proteins CsuA/B and C from the csu operon (which is necessary for biofilm formation). This isolate also underexpressed aconitase B and different enzymes involved in the oxidative stress response (KatE catalase, superoxide dismutase, and alkyl hydroperoxide reductase), suggesting a reduced response to reactive oxygen species (ROS) and, consequently, impaired colistin-mediated cell death through hydroxyl radical production. Col(s) isolates that were indistinguishable by macrorestriction analysis from Ab299 caused six sequential bloodstream infections, and isolates indistinguishable from Ab248 caused severe soft tissue infection, while Col(r) isolates indistinguishable from Ab347 and Ab249 were mainly colonizers. In particular, a Col(s) isolate identical to Ab299 was still invading the bloodstream 90 days after the colonization of this patient by Col(r) isolates. These observations indicate considerably lower invasiveness of A. baumannii clinical isolates following the development of colistin resistance. PMID:24247145

  6. Plasmid-encoded tetracycline efflux pump protein alters bacterial stress responses and ecological fitness of Acinetobacter oleivorans.

    Directory of Open Access Journals (Sweden)

    Hyerim Hong

    Full Text Available Acquisition of the extracellular tetracycline (TC resistance plasmid pAST2 affected host gene expression and phenotype in the oil-degrading soil bacterium, Acinetobacter oleivorans DR1. Whole-transcriptome profiling of DR1 cells harboring pAST2 revealed that all the plasmid genes were highly expressed under TC conditions, and the expression levels of many host chromosomal genes were modulated by the presence of pAST2. The host energy burden imposed by replication of pAST2 led to (i lowered ATP concentrations, (ii downregulated expression of many genes involved in cellular growth, and (iii reduced growth rate. Interestingly, some phenotypes were restored by deleting the plasmid-encoded efflux pump gene tetH, suggesting that the membrane integrity changes resulting from the incorporation of efflux pump proteins also resulted in altered host response under the tested conditions. Alteration of membrane integrity by tetH deletion was shown by measuring permeability of fluorescent probe and membrane hydrophobicity. The presence of the plasmid conferred peroxide and superoxide resistance to cells, but only peroxide resistance was diminished by tetH gene deletion, suggesting that the plasmid-encoded membrane-bound efflux pump protein provided peroxide resistance. The downregulation of fimbriae-related genes presumably led to reduced swimming motility, but this phenotype was recovered by tetH gene deletion. Our data suggest that not only the plasmid replication burden, but also its encoded efflux pump protein altered host chromosomal gene expression and phenotype, which also alters the ecological fitness of the host in the environment.

  7. Identification of an Acinetobacter baumannii zinc acquisition system that facilitates resistance to calprotectin-mediated zinc sequestration.

    Directory of Open Access Journals (Sweden)

    M Indriati Hood

    Full Text Available Acinetobacter baumannii is an important nosocomial pathogen that accounts for up to 20 percent of infections in intensive care units worldwide. Furthermore, A. baumannii strains have emerged that are resistant to all available antimicrobials. These facts highlight the dire need for new therapeutic strategies to combat this growing public health threat. Given the critical role for transition metals at the pathogen-host interface, interrogating the role for these metals in A. baumannii physiology and pathogenesis could elucidate novel therapeutic strategies. Toward this end, the role for calprotectin- (CP-mediated chelation of manganese (Mn and zinc (Zn in defense against A. baumannii was investigated. These experiments revealed that CP inhibits A. baumannii growth in vitro through chelation of Mn and Zn. Consistent with these in vitro data, Imaging Mass Spectrometry revealed that CP accompanies neutrophil recruitment to the lung and accumulates at foci of infection in a murine model of A. baumannii pneumonia. CP contributes to host survival and control of bacterial replication in the lung and limits dissemination to secondary sites. Using CP as a probe identified an A. baumannii Zn acquisition system that contributes to Zn uptake, enabling this organism to resist CP-mediated metal chelation, which enhances pathogenesis. Moreover, evidence is provided that Zn uptake across the outer membrane is an energy-dependent process in A. baumannii. Finally, it is shown that Zn limitation reverses carbapenem resistance in multidrug resistant A. baumannii underscoring the clinical relevance of these findings. Taken together, these data establish Zn acquisition systems as viable therapeutic targets to combat multidrug resistant A. baumannii infections.

  8. Contribution of efflux pumps, porins, and β-lactamases to multidrug resistance in clinical isolates of Acinetobacter baumannii.

    Science.gov (United States)

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

    2013-11-01

    We investigated the mechanisms of resistance to carbapenems, aminoglycosides, glycylcyclines, tetracyclines, and quinolones in 90 multiresistant clinical strains of Acinetobacter baumannii isolated from two genetically unrelated A. baumannii clones: clone PFGE-ROC-1 (53 strains producing the OXA-58 β-lactamase enzyme and 18 strains with the OXA-24 β-lactamase) and clone PFGE-HUI-1 (19 strains susceptible to carbapenems). We used real-time reverse transcriptase PCR to correlate antimicrobial resistance (MICs) with expression of genes encoding chromosomal β-lactamases (AmpC and OXA-51), porins (OmpA, CarO, Omp33, Dcap-like, OprB, Omp25, OprC, OprD, and OmpW), and proteins integral to six efflux systems (AdeABC, AdeIJK, AdeFGH, CraA, AbeM, and AmvA). Overexpression of the AdeABC system (level of expression relative to that by A. baumannii ATCC 17978, 30- to 45-fold) was significantly associated with resistance to tigecycline, minocycline, and gentamicin and other biological functions. However, hyperexpression of the AdeIJK efflux pump (level of expression relative to that by A. baumannii ATCC 17978, 8- to 10-fold) was significantly associated only with resistance to tigecycline and minocycline (to which the TetB efflux system also contributed). TetB and TetA(39) efflux pumps were detected in clinical strains and were associated with resistance to tetracyclines and doxycycline. The absence of the AdeABC system and the lack of expression of other mechanisms suggest that tigecycline-resistant strains of the PFGE-HUI-1 clone may be associated with a novel resistance-nodulation-cell efflux pump (decreased MICs in the presence of the inhibitor Phe-Arg β-naphthylamide dihydrochloride) and the TetA(39) system. PMID:23939894

  9. Risk factors for multi-drug resistant Acinetobacter baumannii bacteremia in patients with colonization in the intensive care unit

    Directory of Open Access Journals (Sweden)

    Kim Se

    2010-07-01

    Full Text Available Abstract Background Epidemic outbreaks of multi-drug resistant (MDR Acinetobacter baumannii (AB in intensive care units (ICUs are increasing. The incidence of MDR AB bacteremia, which develops as a result of colonization, is increasing through widespread dissemination of the pathogen, and further colonization. We sought to determine risk factors for MDR AB bacteremia in patients colonized with MDR AB in the ICU. Methods We conducted a retrospective, observational study of 200 patients colonized with MDR AB in the ICU at Severance Hospital, South Korea during the outbreak period between January 2008 and December 2009. Results Of the 200 patients colonized with MDR AB, 108 developed MDR AB bacteremia, and 92 did not. APACHE II scores were higher in bacteremic than non-bacteremic patients at the time of ICU admission and colonization (24.0 vs. 21.6; P = 0.035, 22.9 vs. 16.8; P P = 0.923, but the duration of time at risk was shorter in bacteremic patients (12.1 vs. 6.0 days; P = 0.016. A recent invasive procedure was a significant risk factor for development of bacteremia (odds ratio = 3.85; 95% CI 1.45-10.24; P = 0.007. Multivariate analysis indicated infection and respiratory failure at the time of ICU admission, maintenance of mechanical ventilation, maintenance of endotracheal tube instead of switching to a tracheostomy, recent central venous catheter insertion, bacteremia caused by other microorganism after colonization by MDR AB, and prior antimicrobial therapy, were significant risk factors for MDR AB bacteremia. Conclusions Patients in the ICU, colonized with MDR AB, should be considered for minimizing invasive procedures and early removal of the invasive devices to prevent development of MDR AB bacteremia.

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

    Directory of Open Access Journals (Sweden)

    Abbas Bahador

    2015-04-01

    Full Text Available Background and Aim: Acinetobacter baumannii a major hospital pathogens and causes outbreaks of infections and associated to nosocomial infections, including bacteremia, pneumonia, meningitis, urinary tract infection, and wound infections. Satureja khuzestaniea province the group Nnayyan and Carvacrol and thymol are antimicrobial activity of this plant. Biofilm-related genes (bap-specific proteins on the cell surface generate a direct role in biofilm formation and infection of the bacteria is eliminated. The aim of this study was to investigate the effect of alcoholic extract Satureja khuzestaniea in gene expression (bap was A. baumanii if it can be as effective as a complementary treatment or therapy in infections caused by these bacteria and inhibit virulence genes used. Materials and Methods: In this study the effect of Satureja khuzestanica essence, an endemic plant of Iran, on the expression level of bap gene in A. baumannii   were investigated. For this purpose, MIC was determined for A. baumanii   . Then, bacteria were treated with S. khuzistanica essence. The bap genes expression in treated and non-treated bacteria, before and after treatment was evaluated using Real time PCR technique. Results: Surprisingly, the expression level of bap gene was decreased in the presence of S. khuzestanica. However, the expression of DNA gyrA gene that was used as an internal control was not altered before and after treatment with this herb. Conclusions: Based on the results, S. khuzestanica could play a, major role in lowering the A. baumannii   resistance to drugs, by reducing bap gene expression. According to results of current research we hope in future be used it to the clinic with a wider range as a complementary therapy and also for surgery operation.

  11. Efficacy of Lysophosphatidylcholine in Combination with Antimicrobial Agents against Acinetobacter baumannii in Experimental Murine Peritoneal Sepsis and Pneumonia Models.

    Science.gov (United States)

    Parra Millán, R; Jiménez Mejías, M E; Sánchez Encinales, V; Ayerbe Algaba, R; Gutiérrez Valencia, A; Pachón Ibáñez, M E; Díaz, C; Pérez Del Palacio, J; López Cortés, L F; Pachón, J; Smani, Y

    2016-08-01

    Immune response stimulation to prevent infection progression may be an adjuvant to antimicrobial treatment. Lysophosphatidylcholine (LPC) is an immunomodulator involved in immune cell recruitment and activation. In this study, we aimed to evaluate the efficacy of LPC in combination with colistin, tigecycline, or imipenem in experimental murine models of peritoneal sepsis and pneumonia. We used Acinetobacter baumannii strain Ab9, which is susceptible to colistin, tigecycline, and imipenem, and multidrug-resistant strain Ab186, which is susceptible to colistin and resistant to tigecycline and imipenem. Pharmacokinetic and pharmacodynamic parameters for colistin, tigecycline, and imipenem and the 100% minimal lethal dose (MLD100) were determined for both strains. The therapeutic efficacies of LPC, colistin (60 mg/kg of body weight/day), tigecycline (10 mg/kg/day), and imipenem (180 mg/kg/day), alone or in combination, were assessed against Ab9 and Ab186 at the MLD100 in murine peritoneal sepsis and pneumonia models. The levels of pro- and anti-inflammatory cytokines, i.e., tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10), were determined by enzyme-linked immunosorbent assay (ELISA) for the same experimental models after inoculating mice with the MLD of both strains. LPC in combination with colistin, tigecycline, or imipenem markedly enhanced the bacterial clearance of Ab9 and Ab186 from the spleen and lungs and reduced bacteremia and mouse mortality rates (P colistin, tigecycline, and imipenem monotherapies. Moreover, at 4 h post-bacterial infection, Ab9 induced higher TNF-α and lower IL-10 levels than those with Ab186 (4 μg/ml versus 3 μg/ml [P colistin, tigecycline, or imipenem modestly reduced the severity of infection by A. baumannii strains with different resistance phenotypes compared to LPC monotherapy in both experimental models. PMID:27161639

  12. A prospective evaluation of synergistic effect of sulbactam and tazobactam combination with meropenem or colistin against multidrug resistant Acinetobacter baumannii

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    Mohammed Ali M.Marie

    2015-10-01

    Full Text Available The present study evaluates the synergistic effect of sulbactam/tazobactam in combination with meropenem or colistin against multidrug resistant (MDR Acinetobacter baumannii isolated from hospitalized patients from a tertiary care hospital in Saudi Arabia. During the study period, 54 multidrug and carbapenem-resistant isolates of A. baumannii isolates were collected from blood and respiratory samples of patients with ventilator-associated pneumonia or bacteremia. Microbroth checkerboard assay (CBA and E-test were performed to look for synergistic interface of sulbactam and tazobactam with meropenem or colistin. All 54 MDR isolates of A. baumannii were resistant to carbapenem. Minimum inhibitory concentration [50/90] value against sulbactam, tazobactam, meropenem, colistin was found to be 64/128, 64/128, 64/256, and 0.5/1.0 respectively. Synergy was detected in more isolates with CBA compared to E-test. All four combinations showed significant synergistic bactericidal activity. However, the combination with colistin showed greater synergistic effect than combination with meropenem. Antagonism was not detected with any of the combinations and any method, but indifference was seen in tazobactam and colistin combination alone. A significant bactericidal effect was seen with sulbactam combination with meropenem or colistin in both methods. A combination therapy can be a choice of treatment. As colistin is known to exhibit nephrotoxicity, the combination of sulbactam and meropenem might be considered as an alternative antibiotic treatment for such multi- and extremely resistant bacteria. Yet, sample size is small in our study, so further well-designed in vitro and clinical studies on large scale should confirm our findings.

  13. Association of biofilm production with multidrug resistance among clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa from intensive care unit

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    Jeetendra Gurung

    2013-01-01

    Full Text Available Background and Aims: Given choice, bacteria prefer a community-based, surface-bound colony to an individual existence. The inclination for bacteria to become surface bound is so ubiquitous in diverse ecosystems that it suggests a strong survival strategy and selective advantage for surface dwellers over their free-ranging counterparts. Virtually any surface, biotic or abiotic (animal, mineral, or vegetable is suitable for bacterial colonization and biofilm formation. Thus, a biofilm is "a functional consortium of microorganisms organized within an extensive exopolymeric matrix." Materials and Methods: The present study was undertaken to detect biofilm production from the repertoire stocks of Acinetobacter baumannii (A. baumannii and Pseudomonas aeruginosa (P. aeruginosa obtained from clinical specimens. The tube method was performed to qualitatively detect biofilm production. Results: A total of 109 isolates of both organisms were included in the study, out of which 42% (46/109 isolates showed biofilm detection. Among the biofilm producers, 57% of P. aeruginosa and 73% of A. baumannii showed multidrug resistance (MDR pattern which was statistically significant in comparison to nonbiofilm producers (P < 0.001. Conclusion: To the best of our knowledge, this is the only study to have tested the biofilm production in both P. aeruginosa and A. baumannii in a single study. Biofilm production and MDR pattern were found to be significantly higher in A. baumannii than P. aeruginosa. Antibiotic resistance was significantly higher among biofilm producing P. aeruginosa than non producers. Similarly, antibiotic resistance was significantly higher among biofilm producing A. baumannii than non producers.

  14. Incidence of Acinetobacter baumannii and other pathogens isolated from Intensive Care Unit of the Hospital San Carlo, Genoa - Voltri

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    Silvana Delfino

    2010-12-01

    Full Text Available Acinetobacter baumannii is an emerging pathogen of great impact especially in nosocomial settings due to its complex epidemiology that makes its control very difficult. In this study the strains isolated from the Intensive Care Unite were analysed. Materials and methods. All the patients admitted into intensive care of San Carlo Hospital,Voltri, Genoa, Italy (ASL 3 in the period from May to December 2009 were considered.A total of 63 patients were studied including 31 women and 32 men, with an average of 73 years old.The study considered the following biological samples (N: bronchial aspirate and sputum (84, urine (55, blood (28, and other materials (36.The positive samples were processed for strain identification and evaluations of its antibiotic susceptibility pattern by standard VITEK2 system, following the Clinical and Laboratory Standard Institute Guidelines. Results and Conclusions. From samples taken into account, the prevalent percentage of bacterial species collected was registered by Gram negative (46.3%, followed by Gram positive (36.4%, and fungi (17.3%. Considering Gram negative isolates A. baumannii and Escherichia coli resulted among the prevalent pathogens (23.4 and 24.5% respectively. This microorganism was collected especially from bronchial aspirate (13 followed by urines (4, blood cultures (2 and other materials (3. On the basis of the analysis of the antibiotic susceptibility tests, colistin was active on the totality (100% of A. baumannii, followed by tigecycline (96.77%.Amikacin resulted also active against a large proportion of these isolates (93.3%. Present findings confirm the great multidrug resistance phenotype of A. baumanii against the main classes of antimicrobial agents and its dangerous diffusion in the Intensive Care Units. For these reasons a continuous surveillance of the evolution of this pathogen toward antibiotic resistance is requested. In this contest it will be important an evaluation of antibiotic

  15. 5-Episinuleptolide Decreases the Expression of the Extracellular Matrix in Early Biofilm Formation of Multi-Drug Resistant Acinetobacter baumannii

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    Sung-Pin Tseng

    2016-07-01

    Full Text Available Nosocomial infections and increasing multi-drug resistance caused by Acinetobacter baumannii have been recognized as emerging problems worldwide. Moreover, A. baumannii is able to colonize various abiotic materials and medical devices, making it difficult to eradicate and leading to ventilator-associated pneumonia, and bacteremia. Development of novel molecules that inhibit bacterial biofilm formation may be an alternative prophylactic option for the treatment of biofilm-associated A. baumannii infections. Marine environments, which are unlike their terrestrial counterparts, harbor an abundant biodiversity of marine organisms that produce novel bioactive natural products with pharmaceutical potential. In this study, we identified 5-episinuleptolide, which was isolated from Sinularia leptoclados, as an inhibitor of biofilm formation in ATCC 19606 and three multi-drug resistant A. baumannii strains. In addition, the anti-biofilm activities of 5-episinuleptolide were observed for Gram-negative bacteria but not for Gram-positive bacteria, indicating that the inhibition mechanism of 5-episinuleptolide is effective against only Gram-negative bacteria. The mechanism of biofilm inhibition was demonstrated to correlate to decreased gene expression from the pgaABCD locus, which encodes the extracellular polysaccharide poly-β-(1,6-N-acetylglucosamine (PNAG. Scanning electron microscopy (SEM indicated that extracellular matrix of the biofilm was dramatically decreased by treatment with 5-episinuleptolide. Our study showed potentially synergistic activity of combination therapy with 5-episinuleptolide and levofloxacin against biofilm formation and biofilm cells. These data indicate that inhibition of biofilm formation via 5-episinuleptolide may represent another prophylactic option for solving the persistent problem of biofilm-associated A. baumannii infections.

  16. 5-Episinuleptolide Decreases the Expression of the Extracellular Matrix in Early Biofilm Formation of Multi-Drug Resistant Acinetobacter baumannii.

    Science.gov (United States)

    Tseng, Sung-Pin; Hung, Wei-Chun; Huang, Chiung-Yao; Lin, Yin-Shiou; Chan, Min-Yu; Lu, Po-Liang; Lin, Lin; Sheu, Jyh-Horng

    2016-01-01

    Nosocomial infections and increasing multi-drug resistance caused by Acinetobacter baumannii have been recognized as emerging problems worldwide. Moreover, A. baumannii is able to colonize various abiotic materials and medical devices, making it difficult to eradicate and leading to ventilator-associated pneumonia, and bacteremia. Development of novel molecules that inhibit bacterial biofilm formation may be an alternative prophylactic option for the treatment of biofilm-associated A. baumannii infections. Marine environments, which are unlike their terrestrial counterparts, harbor an abundant biodiversity of marine organisms that produce novel bioactive natural products with pharmaceutical potential. In this study, we identified 5-episinuleptolide, which was isolated from Sinularia leptoclados, as an inhibitor of biofilm formation in ATCC 19606 and three multi-drug resistant A. baumannii strains. In addition, the anti-biofilm activities of 5-episinuleptolide were observed for Gram-negative bacteria but not for Gram-positive bacteria, indicating that the inhibition mechanism of 5-episinuleptolide is effective against only Gram-negative bacteria. The mechanism of biofilm inhibition was demonstrated to correlate to decreased gene expression from the pgaABCD locus, which encodes the extracellular polysaccharide poly-β-(1,6)-N-acetylglucosamine (PNAG). Scanning electron microscopy (SEM) indicated that extracellular matrix of the biofilm was dramatically decreased by treatment with 5-episinuleptolide. Our study showed potentially synergistic activity of combination therapy with 5-episinuleptolide and levofloxacin against biofilm formation and biofilm cells. These data indicate that inhibition of biofilm formation via 5-episinuleptolide may represent another prophylactic option for solving the persistent problem of biofilm-associated A. baumannii infections. PMID:27483290

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

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    Carattoli Alessandra

    2008-02-01

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

  18. Detection of metallo-β-lactamases producing Acinetobacter baumannii using microbiological assay, disc synergy test and PCR

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    M Purohit

    2012-01-01

    Full Text Available Background: One leading factor responsible for resistance in Acinetobacter baumannii, an important opportunist in health care institutions globally, is the production of carbapenamases like metallo-β-lactamases (MBLs, which hydrolyze a variety of β-lactams including penicillin, cephalosporins and carbapenems. However, neither any standard guidelines are available nor any method has been found to be perfect for their detection. Various methods have shown discordant results, depending upon the employed methodology, β-lactamase substrate and MBL inhibitor used. This study aims to evaluate two phenotypic methods against PCR as gold standard among carbapenem resistant A. baumannii for identifying MBL producers. Materials and Methods: A total of 130 A. baumannii were screened for imipenem and meropenem resistance by Kirby-Bauer disc diffusion method. Phenotypic expression of MBL was detected by EDTA-imipenem-microbiological (EIM assay and extended EDTA disc synergy (eEDS test and presence of bla-IMP and bla-VIM was detected by PCR in all the carbapenem resistant isolates. Results: Of the 43 imipenem and/or meropenem resistant A. baumannii isolates, 4 (9.3% were found to be MBL producers by EIM and 3 (6.97% by eEDS. Only bla-VIM gene was detected in 7 (16.28% by PCR. In addition EIM detected 14 (32.56% carbapenem resistant non-metallo enzyme producers. Conclusion: Of the two MBL genes targeted, bla-VIM was only detected and that too in isolates resistant to both imipenem and meropenem. Further, EIM was useful in differentiating MBL from non-metalloenzymes producers.

  19. Longitudinal analysis of the temporal evolution of Acinetobacter baumannii strains in Ohio, USA, by using rapid automated typing methods.

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    Brooke K Decker

    Full Text Available Genotyping methods are essential to understand the transmission dynamics of Acinetobacter baumannii. We examined the representative genotypes of A. baumannii at different time periods in select locations in Ohio, using two rapid automated typing methods: PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS, a form of multi-locus sequence typing (MLST, and repetitive-sequence-based-PCR (rep-PCR. Our analysis included 122 isolates from 4 referral hospital systems, in 2 urban areas of Ohio. These isolates were associated with outbreaks at 3 different time periods (1996, 2000 and 2005-2007. Type assignments of PCR/ESI-MS and rep-PCR were compared to each other and to worldwide (WW clone types. The discriminatory power of each method was determined using the Simpson's index of diversity (DI. We observed that PCR/ESI-MS sequence type (ST 14, corresponding to WW clone 3, predominated in 1996, whereas ST 12 and 14 co-existed in the intermediate period (2000 and ST 10 and 12, belonging to WW clone 2, predominated more recently in 2007. The shift from WW clone 3 to WW clone 2 was accompanied by an increase in carbapenem resistance. The DI was approximately 0.74 for PCR/ESI-MS, 0.88 for rep-PCR and 0.90 for the combination of both typing methods. We conclude that combining rapid automated typing methods such as PCR/ESI-MS and rep-PCR serves to optimally characterize the regional molecular epidemiology of A. baumannii. Our data also sheds light on the changing sequence types in an 11 year period in Northeast Ohio.

  20. Chaenorhinum semispeluncarum sp. nov. and C. yildirimlii sp. nov. (Scrophulariaceae) from east Anatolia, Turkey

    DEFF Research Database (Denmark)

    Yildirim, Hasan; Tan, Kit; Senol, Serdar;

    2010-01-01

    Chaenorhinum semispeluncarum H. Yildirim, Kit Tan, S. Senol & A. Pirhan sp. nov. and C. yildirimlii Kit Tan, H. Yildirim, S. Senol & A. Pirhan sp. nov. (Scrophulariaceae, C. sect. Microrrhinum) from east Anatolia are described and illustrated. They are both narrow endemics related to the rare C. ...