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Sample records for acinetobacter baumannii emergence

  1. 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

  2. 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.

  3. 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.

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

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    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.

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

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    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

  6. Iron and Acinetobacter baumannii Biofilm Formation

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    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.

  7. Biofilm formation and biocide resistance of acinetobacter baumannii

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    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...

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

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    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...

  9. Antimicrobial resistance and clonality in Acinetobacter baumannii

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    Nemec, Alexandr

    2009-01-01

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

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    Nemec, Alexandr

    2009-01-01

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

  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. 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.

  13. Acinetobacter baumannii in Localised Cutaneous Mycobacteriosis in Falcons

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    Margit Gabriele Muller

    2010-01-01

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

  14. 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

  15. 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

  16. Pharmacodynamics of the Antibacterial Effect of and Emergence of Resistance to Doripenem in Pseudomonas aeruginosa and Acinetobacter baumannii in an In Vitro Pharmacokinetic Model

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    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 ...

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

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    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...

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

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    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.

  19. 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...

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

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    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...

  1. 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.

  2. 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.

  3. 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.

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

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    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.

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

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    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.

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

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    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

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

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    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. Epidemiologic and Clinical Impact of Acinetobacter baumannii Colonization and Infection

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    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

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

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    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.

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

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    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.

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

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    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

  12. Rapid detection of Acinetobacter baumannii and molecular epidemiology of carbapenem-resistant A.baumannii in two comprehensive hospitals of Beijing, China

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    Puyuan eLi

    2015-09-01

    Full Text Available Acinetobacter baumannii is an important opportunistic pathogen associated with a variety of nosocomial infections. A rapid and sensitive molecular detection in clinical isolates is quite needed for the appropriate therapy and outbreak control of A. baumannii. Group 2 carbapenems have been considered the agents of choice for the treatment of multiple drug resistant A. baumannii. But the prevalence of carbapenem-resistant A. baumannii (CRAB has been steadily increasing in recent years. Here, we developed a loop-mediated isothermal amplification (LAMP assay for the rapid detection of A. baumannii in clinical samples by using high-specificity primers of the blaOXA-51 gene. Then we investigated the OXA-carbapenemases molecular epidemiology of A. baumannii isolates in 2 comprehensive hospitals in Beijing. The results showed that the LAMP assay could detect target DNA within 60 min at 65°C. The detection limit was 50 pg/μl, which was about 10-fold greater than that of PCR. Furthermore, this method could distinguish A. baumannii from the homologous A. nosocomialis and A. pittii. A total of 228 positive isolates were identified by this LAMP-based method for A. baumannii from 335 ICU patients with clinically suspected multi-resistant infections in 2 hospitals in Beijing. The rates of CRAB are on the rise and are slowly becoming a routine phenotype for A. baumannii. Among the CRABs, 92.3% harbored both the blaOXA-23 and blaOXA-51 genes. Thirty-three pulsotypes were identified by pulsed-field gel electrophoresis, and the majority belonged to clone C. In conclusion, the LAMP method developed for detecting A. baumannii was faster and simpler than conventional PCR and has great potential for both point-of-care testing and basic research. We further demonstrated a high distribution of class D carbapenemase-encoding genes, mainly OXA-23, which presents an emerging threat in hospitals in China.

  13. 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.

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

    Science.gov (United States)

    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.

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

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    Shu-Chen eKuo

    2015-03-01

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

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

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    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. 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.

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

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    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. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. Identification of an Acinetobacter baumannii zinc acquisition system that facilitates resistance to calprotectin-mediated zinc sequestration.

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    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.

  7. 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

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

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    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.

  9. 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

  10. 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

  11. 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...

  12. Development of TaqMan real-time polymerase chain reaction for the detection of the newly emerging form of carbapenem resistance gene in clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii

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    V Manchanda

    2011-01-01

    Full Text Available Purpose: The newly emerging form of the so-called New Delhi Metallo-beta-lactamases (NDM-1 has been reported recently from patients worldwide and broadly thought as a potential source for the major global health problem. Thus, it is important to study the epidemiology of the so-called NDM-1 harbouring bacteria to prevent its further spread and to place effective control measures. The present study describes the use of the real-time polymerase chain reaction (PCR assay for the detection of the bla NDM-1 gene using TaqMan probes among clinical isolates. Materials and Methods: Clinical isolates of Escherichia coli (11 strains, Klebsiella pneumoniae (17 strains and Acinetobacter baumannii (six strains that were resistant to either of the carbapenems (meropenem or imipenem were included in the study. The presence of carbapenemases in such strains was confirmed using the modified Hodge test. A real-time PCR assay was optimized for the detection of NDM-1 using a cloned synthetic gene fragment followed by testing of the clinical isolates. The findings were further confirmed using PCR and gene sequencing. Results: TaqMan probe assay displayed a good detection limit with analytical sensitivity of the assay up to 10 copies of bla NDM-1 gene per reaction. The isolates of E. coli and K. pneumoniae revealed narrow range crossing point values (Cp values between (12-17 cycles (mean Cp value 14, indicating number of bla NDM-1 gene copies of 106-108. The wider range of Cp values (15-34 cycles with a higher mean Cp value (23.6 was observed in A. baumannii with number of bla NDM-1 gene copies of 103-108. Conclusions: The study demonstrates that real-time PCR assay based on TaqMan chemistry is a useful technique for the detection of bla NDM-1 harbouring clinical isolates of E. coli, K. pneumoniae and A. baumannii. The assay has great precision in measuring the number of bla NDM-1 gene copies per specimen of DNA.

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

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    Hang eYang

    2015-12-01

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

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

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    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.

  15. 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

  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. 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)

  18. 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.

  19. 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.

  20. 产金属β-内酰胺酶的鲍氏不动杆菌在我国内地出现%Emerging metallo-β-lactamases in clinical isolates of Acinetobacter baumannii in China inland

    Institute of Scientific and Technical Information of China (English)

    宗志勇; 吕晓菊; 高燕渝; 俞汝佳

    2004-01-01

    Acquired metallo-β-lactamases (MBLs) are emerging globally and can confer resistance to near all β-lactams. Recently, MBLs were found in Pseudomonas aeruginosa and Citrobacter youngae from China inland, but not in Acinetobacter baumannii. In 2002 and 2003, a few imipenem-resistant and/or ceftazidime-highly-resistant A. baumannii were isolated from clinical specimens in West China Hospital, Sichuan University. By agar dilution method used imipenem with imipenem plus EDTA-1, 10-phenanthroline and/or ceftazidime with ceftazidime plus EDTA-1, 10-phenanthroline, MBLs were detected in 12 nonreplicate A. baumannii isolates. Most of the MBL producers were isolated from sputa of patients with ventilation-associated pneumonia in ICU. PCR for amplifying blaLMP-4 and blavLM-2 for the 12 MBL-producing isolates failed. It demonstrates that MBLs produced by the isolates are MBLs other than IMP-4, VIM-2, VIM-3 and VIM-6.This study is the first report that MBLs are found in A. baumannii in China inland.%获得性金属β-内酰胺酶(金属酶)已经在全球出现,并且能导致对几乎所有β-内酰胺类抗生素耐药.近来,金属酶已经在我国的铜绿假单胞菌和杨氏柠檬酸菌中发现,但尚未在鲍氏不动杆菌中发现.2002和2003年,从四川大学华西医院的临床标本中分离出一些亚胺培南耐药或头孢他啶高度耐药的鲍氏不动杆菌菌株.通过亚胺培南联合亚胺培南-EDTA-邻二氮菲或头孢他啶联合头孢他啶-EDTA-邻二氮菲的琼脂稀释法,检测出12株不重复的鲍氏不动杆菌产金属酶.这些产金属酶的菌株主要分离自机械通气相关性肺炎患者的痰标本.PCR扩增IMP-4和VIM-2的编码基因无阳性结果.说明这些菌株所产的金属酶并非IMP-4、VIM-2、VIM-3和VIM-6.这是首次在我国内地发现有产金属酶的鲍氏不动杆菌.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Science.gov (United States)

    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.

  3. 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...

  4. 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.

  5. 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

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

    Science.gov (United States)

    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

  7. 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.  

  8. Complete genome sequence of Acinetobacter baumannii XH386 (ST208, a multi-drug resistant bacteria isolated from pediatric hospital in China

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    Youhong Fang

    2016-03-01

    Full Text Available Acinetobacter baumannii is an important bacterium that emerged as a significant nosocomial pathogen worldwide. The rise of A. baumannii was due to its multi-drug resistance (MDR, while it was difficult to treat multi-drug resistant A. baumannii with antibiotics, especially in pediatric patients for the therapeutic options with antibiotics were quite limited in pediatric patients. A. baumannii ST208 was identified as predominant sequence type of carbapenem resistant A. baumannii in the United States and China. As we knew, there was no complete genome sequence reproted for A. baumannii ST208, although several whole genome shotgun sequences had been reported. Here, we sequenced the 4087-kilobase (kb chromosome and 112-kb plasmid of A. baumannii XH386 (ST208, which was isolated from a pediatric hospital in China. The genome of A. baumannii XH386 contained 3968 protein-coding genes and 94 RNA-only encoding genes. Genomic analysis and Minimum inhibitory concentration assay showed that A. baumannii XH386 was multi-drug resistant strain, which showed resistance to most of antibiotics, except for tigecycline. The data may be accessed via the GenBank accession number CP010779 and CP010780.

  9. 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

  10. 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.

  11. 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.

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

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    Saghi

    2015-02-01

    Full Text Available Background Infection due to Acinetobacter baumannii has become a significant challenge to modern healthcare systems. The rapid emergence and global dissemination of A. baumannii as a major nosocomial pathogen is remarkable and it demonstrates its successful adaptation to the 21st century hospital environment. Recent studies have discussed about essential oil of Origanum vulgare against a range of bacteria, including various species of Staphylococcus, Pseudomonas, Bacillus and Escherichia coli. Objectives The present study aimed to investigate the inhibitory effects O. vulgare essence against multidrug-resistant (MDR strains of A. baumannii from selected hospitals in Tehran, Iran. Materials and Methods This oil was obtained using the hydrodistillation method and analyzed by gas chromatography mass spectrography (GC/MS. The antimicrobial activity against MDR isolates was achieved using disc diffusion method and macro-broth dilution assay. Results Analysis of the essential oil revealed the presence of pulegone (68.59% piperitone (7.8%, piperitenone (7.8%, 1, 8-cineole (1.3%, and carvacrol (1.6% as the major components. The results showed a significant activity against MDR A. baumannii with inhibition zones and minimal inhibitory concentration values in the ranges of 7-15 mm and 20-35 µL/mL respectively. Conclusions This investigation showed that the essence oil of O. vulgare had a potent antimicrobial activity against MDR A. baumannii. Further research is required to evaluate the practical values of therapeutic applications.

  13. 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...

  14. 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

  15. 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.

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

    Science.gov (United States)

    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

  17. 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

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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)

  3. 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.

  4. 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

  5. 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

  6. 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

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

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    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.

  8. 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

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

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    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.

  10. 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

  11. 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.

  12. 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. ...

  13. 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.

  14. A 5-year Surveillance Study on Antimicrobial Resistance of Acinetobacter baumannii Clinical Isolates from a Tertiary Greek Hospital

    Science.gov (United States)

    2016-01-01

    Background Acinetobacter baumannii has emerged as a major cause of nosocomial outbreaks. It is particularly associated with nosocomial pneumonia and bloodstream infections in immunocompromised and debilitated patients with serious underlying pathologies. Over the last two decades, a remarkable rise in the rates of multidrug resistance to most antimicrobial agents that are active against A. baumannii has been noted worldwide. We evaluated the rates of antimicrobial resistance and changes in resistance over a 5-year period (2010–2014) in A. baumannii strains isolated from hospitalized patients in a tertiary Greek hospital. Materials and Methods Identification of A. baumannii was performed by standard biochemical methods and the Vitek 2 automated system, which was also used for susceptibility testing against 18 antibiotics: ampicillin/sulbactam, ticarcillin, ticarcillin/clavulanic acid, piperacillin, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, meropenem, gentamicin, amikacin, tobramycin, ciprofloxacin, tetracycline, tigecycline, trimethoprim/sulfamethoxazole, and colistin. Interpretation of susceptibility results was based on the Clinical and Laboratory Standards Institute criteria, except for tigecycline, for which the Food and Drug Administration breakpoints were applied. Multidrug resistance was defined as resistance to ≥3 classes of antimicrobial agents. Results Overall 914 clinical isolates of A. baumannii were recovered from the intensive care unit (ICU) (n = 493), and medical (n = 252) and surgical (n = 169) wards. Only 4.9% of these isolates were fully susceptible to the antimicrobials tested, while 92.89% of them were multidrug resistant (MDR), i.e., resistant to ≥3 classes of antibiotics. ICU isolates were the most resistant followed by isolates from surgical and medical wards. The most effective antimicrobial agents were, in descending order: colistin, amikacin, trimethoprim/sulfamethoxazole, tigecycline, and tobramycin

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

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    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.

  16. 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...

  17. 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...

  18. 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.

  19. Nuclear translocation of Acinetobacter baumannii transposase induces DNA methylation of CpG regions in the promoters of E-cadherin gene.

    Directory of Open Access Journals (Sweden)

    Dong Chan Moon

    Full Text Available Nuclear targeting of bacterial proteins has emerged as a pathogenic mechanism whereby bacterial proteins induce host cell pathology. In this study, we examined nuclear targeting of Acinetobacter baumannii transposase (Tnp and subsequent epigenetic changes in host cells. Tnp of A. baumannii ATCC 17978 possesses nuclear localization signals (NLSs, (225RKRKRK(230. Transient expression of A. baumannii Tnp fused with green fluorescent protein (GFP resulted in the nuclear localization of these proteins in COS-7 cells, whereas the truncated Tnp without NLSs fused with GFP were exclusively localized in the cytoplasm. A. baumannii Tnp was found in outer membrane vesicles, which delivered this protein to the nucleus of host cells. Nuclear expression of A. baumannii Tnp fused with GFP in A549 cells induced DNA methylation of CpG regions in the promoters of E-cadherin (CDH1 gene, whereas the cytoplasmic localization of the truncated Tnp without NLSs fused with GFP did not induce DNA methylation. DNA methylation in the promoters of E-cadherin gene induced by nuclear targeting of A. baumannii Tnp resulted in down-regulation of gene expression. In conclusion, our data show that nuclear traffic of A. baumannii Tnp induces DNA methylation of CpG regions in the promoters of E-cadherin gene, which subsequently down-regulates gene expression. This study provides a new insight into the epigenetic control of host genes by bacterial proteins.

  20. 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

  1. 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

  2. 5-Episinuleptolide Decreases the Expression of the Extracellular Matrix in Early Biofilm Formation of Multi-Drug Resistant Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    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.

  3. 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

  4. 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...

  5. 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 ...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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

  11. 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.

  12. 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

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

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    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-01

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

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

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    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 

  16. 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. GES-11-producing Acinetobacter baumannii clinical isolates from Tunisian hospitals: Long-term dissemination of GES-type carbapenemases in North Africa.

    Science.gov (United States)

    Chihi, H; Bonnin, R A; Bourouis, A; Mahrouki, S; Besbes, S; Moussa, M Ben; Belhadj, O; Naas, T

    2016-06-01

    Acinetobacter baumannii is an emerging threat in healthcare facilities owing to its ability to be multidrug-resistant (MDR) and to be involved in outbreaks. GES-type extended-spectrum β-lactamases (ESBLs) have been increasingly identified in A. baumannii. In this study, clinical A. baumannii isolates were characterised using standard biochemical methods and antibiotic susceptibility testing. Antibiotic resistance genes were sought by PCR and sequencing. Genetic support was characterised using S1 nuclease pulsed-field gel electrophoresis (PFGE) mapping, conjugation and electroporation assays. The genetic environment was investigated by PCR, and genetic relatedness was investigated by PFGE. Two MDR A. baumannii clinical isolates susceptible only to colistin and rifampicin were isolated from a tracheal aspirate of a 49-year-old woman hospitalised in 2006 at the Military Hospital of Tunis, Tunisia, and from a tracheal aspirate of a 53-year-old man hospitalised in 2010 at the Institut Orthopédique Mohamed El Kassab of Tunis, Tunisia. PCR revealed that the two isolates harboured the acquired carbapenemase blaOXA-23 and ESBL blaGES-11 genes along with chromosomally-encoded blaOXA-51 and blaADC-like genes. PFGE revealed that these A. baumannii isolates were unrelated; nevertheless, plasmid analysis revealed a similar sized plasmid following electrophoresis of the isolates. In addition, A. baumannii CIP70.10 transformants displayed similar resistance patterns. blaGES-11 was integron-borne and the ISAbaI element was identified upstream of blaOXA-23 and blaADC-like. Here we described two unrelated clinical A. baumannii isolates producing GES-11 ESBL and OXA-23 carbapenemase from two Tunisian hospitals. This work further illustrates the emergence of GES-type β-lactamases in A. baumannii in North Africa as early as 2006. PMID:27436466

  1. 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

  2. The influence of carbapenem resistance on mortality in solid organ transplant recipients with Acinetobacter baumannii infection

    Directory of Open Access Journals (Sweden)

    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

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

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    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.

  4. 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.

  5. 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

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

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    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

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

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    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.

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

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    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

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

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    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

  10. 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. ...

  11. 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

  12. 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

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

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    Guillermo D Repizo

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

  14. 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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  17. 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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  20. 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

  1. Acinetobacter baumannii Infection in the Neonatal Intensive Care Unit

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    AMK AL Jarousha

    2008-09-01

    Full Text Available Background: To perform a prospective case control study of blood stream infection to determine the infection rate of Acine­tobac­ter baumannii and the risk factors associated with mortality."nMethods:   From February 2004 to January 2005, 579 consecutive episodes of blood stream infection were obtained at two neo­na­tal intensive care units Al Nasser and Al Shifa hospitals in Gaza City. Forty (6.9% isolates of A. baumannii were ob­tained from the neonates under 28 d. Most of the isolates (92% were from hospitalized patients in the intensive care units."nResults: Community acquired infection was 8%.  Sixty three percent of the patients were males. The isolates of A. bauman­nii were resistant to commonly used antibiotics while being sensitive to meropenem (92.5%, imipenem (90%, chloram­pheni­col (80%, ciprofloxacin (75%, gentamicin (57.5%, ceftriaxone (50%, amikacin (37.5%, cefuroxime and ce­fo­taxime (35%. Over all crude mortality rate was 20% with much higher crude mortality among patients with noso­co­mial infec­tion.  Based on logistic regression, the following factors were statistically significant: weight < 1500g, age < 7 d, mean of hospitalization equal 20 days, antibiotic use, and mechanical ventilation, when compared to the control group (P< 0.05."nConclusion:  Infection rate of nosocomial blood stream infection was considerable and alarming in neonatal intensive care unit infants and associated with a significant excess length of NICU stay and a significant economic burden.  

  2. Prevalence of metallo-beta-lactamase among Pseudomonas aeruginosa and Acinetobacter baumannii in a Korean university hospital and comparison of screening methods for detecting metallo-beta-lactamase.

    Science.gov (United States)

    Oh, Eun-Jee; Lee, Seungok; Park, Yeon-Joon; Park, Jung Jun; Park, Kanggyun; Kim, Sang-Il; Kang, Moon Won; Kim, Byung Kee

    2003-09-01

    To identify the metallo-beta-lactamases (MBLs) prevalent in Korea, a total of 130 clinical isolates of Pseudomonas aeruginosa and Acinetobacter baumannii (99 P. aeruginosa and 31 A. baumannii) with a reduced susceptibility to imipenem (IPM) and/or ceftazidime (CAZ) was subjected to PCR analyses with primers specific to bla(IMP-1), bla(VIM-1), and bla(VIM-2). In addition, inhibitor-potentiated disk diffusion methods (IPD) using two kinds of substrate-inhibitor combinations (ceftazidime-2-mercaptopropionic acid (2MPA) and imipenem-EDTA) were investigated. Thirty-three isolates (29 P. aeruginosa and 4 A. baumannii) carried bla(VIM-2) and two P. aeruginosa isolates harbored bla(IMP-1). The enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) pattern revealed that many of the VIM-2-producing P. aeruginosa isolates were clonally related, whereas the A. baumannii isolates were diverse. The inhibitor-potentiated disk diffusion test using imipenem-EDTA was highly sensitive and specific for detecting the VIM-2 producer. These results suggest that VIM-2 is an important MBL in P. aeruginosa and A. baumannii in the Korean hospital of this study and that the IMP-1-producing P. aeruginosa has also emerged. Screening for MBLs and strict infection control for these isolates will contribute to prevent further spread of resistance. PMID:12842488

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

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    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

  4. Adjuvant role of Pseudomonas flagellin for Acinetobacter baumannii biofilm associated protein

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    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

  5. Differences in Acinetobacter baumannii strains and host innate immune response determine morbidity and mortality in experimental pneumonia.

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    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.

  6. 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.

  7. 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.

  8. Antimicrobial action of zinc oxide nanoparticles in combination with ciprofloxacin and ceftazidime against multidrug-resistant Acinetobacter baumannii.

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

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    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

  10. 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

  11. 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.

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

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    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.

  13. 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.

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

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    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

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

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    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

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

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    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.

  17. 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.

  18. 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

  19. Abrp, a new gene, confers reduced susceptibility to tetracycline, glycylcine, chloramphenicol and fosfomycin classes in Acinetobacter baumannii.

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    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

  20. Genomic comparison of multi-drug resistant invasive and colonizing Acinetobacter baumannii isolated from diverse human body sites reveals genomic plasticity

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    Hsiao William W

    2011-06-01

    Full Text Available 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-field gel electrophoresis, multi-locus sequence typing and antibiotic resistance profiles demonstrated genotypic and phenotypic variation. Each isolate was sequenced to high-quality draft status, which allowed for comparative genomic analyses with existing A. baumannii genomes. A high resolution, whole genome alignment method detailed the phylogenetic relationships of sequenced A. baumannii and found no correlation between phylogeny and body site of isolation. This method identified genomic regions unique to both those isolates found on the surface of the skin or in wounds, termed colonization isolates, and those identified from body fluids, termed invasive isolates; these regions may play a role in the pathogenesis and spread of this important pathogen. A PCR-based screen of 74 A. baumanii isolates demonstrated that these unique genes are not exclusive to either phenotype or isolation source; however, a conserved genomic region exclusive to all sequenced A. baumannii was identified and verified. Conclusions The results of the comparative genome analysis and PCR assay show that A. baumannii is a diverse and genomically variable pathogen that appears to have the potential to cause a range of human disease regardless of the isolation source.

  1. Identification of a general O-linked protein glycosylation system in Acinetobacter baumannii and its role in virulence and biofilm formation.

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    Jeremy A Iwashkiw

    Full Text Available Acinetobacter baumannii is an emerging cause of nosocomial infections. The isolation of strains resistant to multiple antibiotics is increasing at alarming rates. Although A. baumannii is considered as one of the more threatening "superbugs" for our healthcare system, little is known about the factors contributing to its pathogenesis. In this work we show that A. baumannii ATCC 17978 possesses an O-glycosylation system responsible for the glycosylation of multiple proteins. 2D-DIGE and mass spectrometry methods identified seven A. baumannii glycoproteins, of yet unknown function. The glycan structure was determined using a combination of MS and NMR techniques and consists of a branched pentasaccharide containing N-acetylgalactosamine, glucose, galactose, N-acetylglucosamine, and a derivative of glucuronic acid. A glycosylation deficient strain was generated by homologous recombination. This strain did not show any growth defects, but exhibited a severely diminished capacity to generate biofilms. Disruption of the glycosylation machinery also resulted in reduced virulence in two infection models, the amoebae Dictyostelium discoideum and the larvae of the insect Galleria mellonella, and reduced in vivo fitness in a mouse model of peritoneal sepsis. Despite A. baumannii genome plasticity, the O-glycosylation machinery appears to be present in all clinical isolates tested as well as in all of the genomes sequenced. This suggests the existence of a strong evolutionary pressure to retain this system. These results together indicate that O-glycosylation in A. baumannii is required for full virulence and therefore represents a novel target for the development of new antibiotics.

  2. Tigecycline resistance in Acinetobacter baumannii mediated by frameshift mutation in plsC, encoding 1-acyl-sn-glycerol-3-phosphate acyltransferase.

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    Li, X; Liu, L; Ji, J; Chen, Q; Hua, X; Jiang, Y; Feng, Y; Yu, Y

    2015-03-01

    Acinetobacter baumannii is an important pathogen of healthcare-associated infections and shows multidrug resistance. With the increasing application of tigecycline, isolates resistant to this antibiotic are of growing concern clinically. However, the definitive mechanism of tigecycline resistance remains unclear. To explore the mechanism of tigecycline resistance in A. baumannii, a tigecycline-resistant strain was obtained by increasing the concentration of the antimicrobial in liquid culture. Three mutations were identified by the whole genome comparison, including one synonymous substitution in a hypothetical protein and a frameshift mutation in plsC and omp38. The plsC gene was confirmed to cause decreased susceptibility to tigecycline by a complementation experiment and cellular membrane change was detected by flow cytometry. By measuring the relative growth rate, the fitness cost of plsC was estimated to be approximately 8 %. In conclusion, plsC was found to play an important role in tigecycline resistance in A. baumannii. The minor fitness cost of plsC indicates a high risk of the emergence and development of tigecycline resistance in A. baumannii.

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

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    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

  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. 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

  6. 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

  7. 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.

  8. Detection of AdeABC efflux pump genes in tetracycline-resistant Acinetobacter baumannii isolates from burn and ventilator-associated pneumonia patients

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    Maryam Beheshti

    2014-01-01

    Full Text Available Purpose: Acinetobacter baumannii is the most prevalent nosocomial pathogen which have been emerged in the past three decades worldwide. The aim of this study was to assess the distribution of the AdeABC efflux pump genes, associated with tetracycline resistance in Acinetobacter baumannii isolates collected from burn infection and Ventilator Associated Pneumonia (VAP. Materials and Methods: Ninety-eight A. baumannii isolates were collected from two different hospitals in Tehran, Iran. Tetracycline susceptibility testing was performed by disk diffusion and agar dilution methods according to the CLSI guidelines. The presence of adeSR, adeB, drug efflux system genes in resistant isolates was assessed by polymerase chain reaction (PCR. Carbonyl cyanide 3-chlorophenylhydrazone (CCCP was used as a chemical inhibitor agent to assess the contribution of AdeABC efflux pump in tetracycline resistance isolates. Results: Approximately 48% (47 out of 98 of isolates showed resistance to tetracycline which 14 (14.2% isolates were corresponded to burn infection and the remaining 33 (33.8% strains were isolated from VAP. All tetracycline resistant isolates have AdeABC in PCR assay. The reduction of tetracycline MICs by using 50 μg/ml CCCP were as follows: in 18 isolates 2-4 fold reduction in MICs, 26 isolates showed 8 fold reduction,1 isolate showed 16 fold, 1 isolate showed 32 fold and the remaining 1 isolate showed 128 fold reduction in MICs. Conclusion: The results showed significant correlation between tetracycline resistance and AdeABC efflux pump genes in resistant A. baumannii isolates.

  9. 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.

  10. 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.

  11. Nosocomial outbreaks due to Pseudomonas aeruginosa and Acinetobacter baumannii in a Neonatal Intensive Care Unit (NICU of the Uberlândia Federal University Hospital Surto hospitalar por Pseudomonas aeruginosa e Acinetobacter baumannii em uma Unidade de Terapia Intensiva Neonatal (UTIN do Hospital de Clínicas da Universidade Federal de Uberlândia (HC-UFU

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    Denise Von Dolinger de Brito

    2003-11-01

    Full Text Available The study documents the occurrence of two subsequent outbreaks in the NICU of HC-UFU, caused by epidemic strains of multiresistant Pseudomonas aeruginosa and Acinetobacter baumannii, that occurred between March/01 and September and between October/01 and March/02, respectively. The P. aeruginosa outbreak included seven neonates with conjunctivitis and three with bacteremia. A case-control study was conducted for the A. baumannii outbreak, with 11 and 22 neonates, respectively. The isolates of A. baumannii were resistant to gentamacin and ciprofloxacin. P. aeruginosa isolates were resistant to ampicillin/sulbactam gentamicin and ciprofloxacin. The hands of healthcare workers and environmental cultures were negative. The outbreak of P. aeruginosa resulted in the increase of use of imipenem, which could have favoured the emergence of a A. baumannii epidemic strain, despite of its susceptibility to this antibiotic. The risk factors for A. baumannii infection were: weight 7 days and use of carbapenems. Containment of the two outbreaks was achieved by introduction of strict hygiene measures and careful nursing care of the infected infants. The reservatory and the route of transmission were not found.O objetivo foi relatar a ocorrência de dois surtos subseqüentes na UTIN do HC-UFU, por amostras epidêmicas de P. aeruginosa e A. baumannii multirresistentes nos períodos de Mar - Set/01 e Out - Mar/02, respectivamente. O surto por P. aeruginosa incluiu sete neonatos com conjuntivite e três com bacteremia e um estudo caso-controle foi realizado no surto por A. baumannii com 11 e 22 neonatos respectivamente. Os isolados de A. baumannii foram resistentes a gentamicina e ciprofloxacina e os de P. aeruginosa a ampicilina/sulbactam além de gentamicina e ciprofloxacina. As culturas ambientais e das mãos dos profissionais de saúde foram negativas. O surto por P. aeruginosa resultou no aumento do uso de imipenem o que pode ter favorecido a emergência do

  12. 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.

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

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    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.

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

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    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. Structure determination of LpxA 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

    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

  16. 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

  17. 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.

  18. 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.

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

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    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.

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

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    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.

  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. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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...

  8. 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...

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

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    Mirjana Lulic-Botica

    2011-01-01

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

  10. 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

  11. 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

  12. 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.

  13. 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

  14. 多聚β-1-6-N-乙酰氨基葡萄糖胺对鲍氏不动杆菌生物膜形成及耐药的影响%Influence of poly-β-1-6-N-acetylglucosamine on biofilm formation and drug resistance of Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    郭海娜; 向军

    2015-01-01

    Acinetobacter baumannii has emerged as one of the leading bacteria for nosocomial infections,especially in burn wards and ICUs.The bacteria can easily form biofilm and readily attach to abiotic and biotic surfaces,resulting in persistent biofilm-mediated infections.Being surrounded by selfproduced extracellular polymeric substance (EPS),the microorganisms in biofilm can acquire protective property against detrimental environment and their tolerance toward antibiotics is increased.Poly-β-1-6-N-acetylglucosamine (PNAG),the common constituent of EPS in Acinetobacter baumannii,acts as the key virulence factor and plays a crucial role in biofilm formation process.This review describes the properties and functions of the PNAG and its influence on biofilm formation and drug resistance of Acinetobacter baumannii.

  15. [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

  16. Transmission Electron Microscopic Morphological Study and Flow Cytometric Viability Assessment of Acinetobacter baumannii Susceptible to Musca domestica cecropin

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    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.

  17. 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.

  18. 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.

  19. 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

  20. Phenotypic detection of metallo-β-lactamases in Pseudomonas aeruginosa and Acinetobacter baumannii isolated from hospitalized patients in São Luis, State of Maranhão, Brazil

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    Roberto Morais Luz de Carvalho

    2013-07-01

    Full Text Available Introduction Acquired metallo-β-lactamases (MβL are emerging determinants of resistance in Pseudomonas aeruginosa and Acinetobacter baumannii. The objectives of this study were to phenotypically detect MβL in imipenem-resistant P. aeruginosa and A. baumannii, to investigate the association between MβL-positive strains and hospitals, and to compare the resistance profiles of MβL-producing and non-MβL-producing strains. Methods The approximation disk and combined disk assay methods were used in this study. Results A total of 18 (38.3% P. aeruginosa isolates and 1 (5.6% A. baumannii isolate tested positive for the presence of MβL. Conclusions These results demonstrate the need for strict surveillance and for the adoption of preventive measures to reduce the spread of infection and potential outbreaks of disease caused by MβL-producing microorganisms.

  1. 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

  2. Study of the major essential oil compounds of Coriandrum sativum against Acinetobacter baumannii and the effect of linalool on adhesion, biofilms and quorum sensing.

    Science.gov (United States)

    Alves, Susana; Duarte, Andreia; Sousa, Sónia; Domingues, Fernanda C

    2016-01-01

    Acinetobacter baumannii is a pathogen that has the ability to adhere to surfaces in the hospital environment and to form biofilms which are increasingly resistant to antimicrobial agents. The aim of this work was to study the antimicrobial activity of the major oil compounds of Coriandrum sativum against A. baumannii. The effect of linalool on planktonic cells and biofilms of A. baumannii on different surfaces, as well as its effect on adhesion and quorum sensing was evaluated. From all the compounds evaluated, linalool was the compound with the best antibacterial activity, with minimum inhibitory concentration values between 2 and 8 μl ml(-1). Linalool also inhibited biofilm formation and dispersed established biofilms of A. baumannii, changed the adhesion of A. baumannii to surfaces and interfered with the quorum- sensing system. Thus, linalool could be a promising antimicrobial agent for controlling planktonic cells and biofilms of A. baumannii.

  3. 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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. CARBAPENEM-RESISTANT ACINETOBACTER BAUMANII POSTOPERATIVE MENINGITIS

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    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.

  8. 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...

  9. Association of biofilm production with multidrug resistance among clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa from intensive care unit

    Directory of Open Access Journals (Sweden)

    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.

  10. Crude oil degradation efficiency of a recombinant Acinetobacter baumannii strain and its survival in crude oil-contaminated soil microcosm.

    Science.gov (United States)

    Mishra, Sanjeet; Sarma, Priyangshu M; Lal, Banwari

    2004-06-15

    A hydrocarbon degrading Acinetobacter baumannii S30 strain, isolated from crude oil-contaminated soil, was inserted with the lux gene from the luciferase gene cassette luxCDABE. Soil microcosms were designed to study the degradation efficacy for total petroleum hydrocarbon (TPH) of crude oil by lux-tagged A. baumannii S30 pJES. Bioaugmentation of a TPH-contaminated microcosm with A baumannii S30 pJES showed that TPH levels were reduced from 89.3 to 53.9 g/kg soil in 90 days. Biodegradation of TPH by A baumannii S30 pJES was also monitored in shake flask conditions, which showed a reduction of initial TPH levels by over 50% at the end of 120 h. A lux-PCR-based approach along with the standard dilution plating with selective antibiotics was successfully utilized to monitor the survivability of the lux-tagged strain A. baumannii S30 pJES in soil microcosms and stability of the lux insert in the host strain A. baumannii S30. The selective plating technique indicated the population of A. baumannii S30 pJES to be 6.5+/-0.13 x 10(8) CFU/g at day zero (just after bioaugmentation) and 2.09+/-0.08 x 10(8) CFU/g of soil after 90 days of incubation. lux-PCR confirmed the stability of the insert in all the randomly selected colonies of A. baumannii strains from the antibiotic plates. The lux insert was stable after 50 generations in Luria Bertini broth and storage at -70 degrees C as glycerol stocks for over a year. These results revealed that the lux insert was stable and lux-tagged A. baumannii S30 strain could survive in a TPH-contaminated soil microcosm and could degrade TPH in the soil microcosm conditions. It can be used as an effective marker to monitor the survival of augmented strains at a bioremediation site. PMID:15183881

  11. Prevalence of 16S rRNA methylase, modifying enzyme, and extended-spectrum beta-lactamase genes among Acinetobacter baumannii isolates.

    Science.gov (United States)

    Liu, Zhenru; Ling, Baodong; Zhou, Liming

    2015-08-01

    Multidrug-resistant Acinetobacter baumannii has become a worldwide problem, and methylation of 16S rRNA has recently emerged as a new mechanism of resistance to aminoglycosides, which is mediated by a newly recognized group of 16S rRNA methylases. 16S rRNA methylase confers a high-level resistance to all 4,6-substituted deoxystreptamine aminoglycosides that are currently used in clinical practice. Some of the A. baumannii isolates have been found to coproduce extended-spectrum beta-lactamases (ESBLs), contributing to their multidrug resistance. The aim of this study was to detect the determinants of the 16S rRNA methylase genes armA, rmtA, rmtB, rmtC, rmtD, rmtE, and npmA, the modifying enzyme genes aac(6')-Ib, ant(3″)-Ia, aph(3')-I, and the extended-spectrum beta-lactamase genes bla(TEM), bla(SHV), and bla(CTX-M-3) among A. baumannii isolates in northeastern Sichuan, China. Minimum inhibitory concentrations (MICs) of 21 different antimicrobial agents against the A. baumannii isolates were determined. The clinical isolates showed a high level of resistance (MIC≧256 μg/ml) to aminoglycosides, which ranged from 50·1 to 83·8%. The resistances to meropenem and imipenem, two of the beta-lactam antibiotics and the most active antibiotics against A. baumannii, were 9·1 and 8·2%, respectively. Among 60 amikacin-resistant isolates, only the 16S rRNA methylase gene armA was found to be prevalent (66·7%), but the other 16S rRNA methylase genes rmtA, rmtB, rmtC, rmtD, rmtE, and npmA were not detected. The prevalences of the modifying enzyme genes aac (6')-Ib, ant (3″)-Ia, and aph (3')-I were 51·7, 81·7, and 58·3%, respectively, which are different from a previous study in which the occurrences of these genes were 3, 64, and 72%, respectively. Among the 40 isolates that were armA-positive, the prevalences of bla(TEM), bla(SHV), and bla(CTX-M-3) genes were detected for the first time in China, and their occurrences were 45, 65, and 52·5%, respectively. In all, A

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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 ...

  19. 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...

  20. 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

  1. 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.

  2. Comparative Genomic Analysis of Rapid Evolution of an Extreme-Drug-Resistant Acinetobacter baumannii Clone

    DEFF Research Database (Denmark)

    Tan, Sean Yang-Yi; Chua, Song Lin; Liu, Yang;

    2013-01-01

    The emergence of extreme-drug-resistant (EDR) bacterial strains in hospital and nonhospital clinical settings is a big and growing public health threat. Understanding the antibiotic resistance mechanisms at the genomic levels can facilitate the development of next-generation agents. Here, compara......The emergence of extreme-drug-resistant (EDR) bacterial strains in hospital and nonhospital clinical settings is a big and growing public health threat. Understanding the antibiotic resistance mechanisms at the genomic levels can facilitate the development of next-generation agents. Here...... that a putative porin protein was down-regulated when A. baumannii 53264 was exposed to antimicrobials, which may reduce the entry of antibiotics into the bacterial cell....

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. 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

  6. 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

  7. 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

  8. 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.

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

    Science.gov (United States)

    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

  10. 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.

  11. 急诊重症监护室鲍曼不动杆菌感染分析及防治%Analyzing and Controlling the Acinetobacter Baumannii Infection in Emergency Intensive Care Unit

    Institute of Scientific and Technical Information of China (English)

    陈美娟; 吕火祥; 张美齐

    2011-01-01

    目的 分析急诊重症监护室(EICU)鲍曼不动杆菌(Acinetobacter baumanii,AB)感染的分布特点及耐药情况,为预防和治疗AB感染提供依据.方法 回顾性分析了2009年10月~2011年1月EICU采集的98株AB标本的分布与耐药情况.结果 98株AB标本,主要为痰液来源,为80株,占81.6%.药敏试验显示AB对头孢他啶、哌拉西林/他唑巴坦的耐药率均超过60%;对环丙沙星、左氧氟沙星、氨曲南、复方新诺明、庆大霉素的耐药率分别为73.6%、60.2%、79.3%、70.3%、68.3%;对亚胺培南、美洛培南分别为49.5%、50.6%.米诺环素及头孢哌酮/舒巴坦、多黏菌素B的耐药率较低,分别为21.3%、35.6%、6.8%.结论 为有效控制AB引起的院内感染,可先经验性地选用头孢哌酮/舒巴坦或碳青霉稀类,后及时根据药敏结果调整用药方案.严格消毒隔离措施,增强患者的机体免疫力也十分重要.

  12. 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.

  13. 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.

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

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    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.

  15. 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

  16. 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.

  17. 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

  18. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. 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

  2. In Vivo and In Vitro Efficacy of Minocycline-Based Combination Therapy for Minocycline-Resistant Acinetobacter baumannii.

    Science.gov (United States)

    Yang, Ya-Sung; Lee, Yi; Tseng, Kuo-Chuan; Huang, Wei-Cheng; Chuang, Ming-Fen; Kuo, Shu-Chen; Lauderdale, Tsai-Ling Yang; Chen, Te-Li

    2016-07-01

    Minocycline-based combination therapy has been suggested to be a possible choice for the treatment of infections caused by minocycline-susceptible Acinetobacter baumannii, but its use for the treatment of infections caused by minocycline-resistant A. baumannii is not well established. In this study, we compared the efficacy of minocycline-based combination therapy (with colistin, cefoperazone-sulbactam, or meropenem) to that of colistin in combination with meropenem for the treatment of minocycline-resistant A. baumannii infection. From 2006 to 2010, 191 (17.6%) of 1,083 A. baumannii complex isolates not susceptible to minocycline from the Taiwan Surveillance of Antimicrobial Resistance program were collected. Four representative A. baumannii isolates resistant to minocycline, amikacin, ampicillin-sulbactam, ceftazidime, ciprofloxacin, cefepime, gentamicin, imipenem, levofloxacin, meropenem, and piperacillin-tazobactam were selected on the basis of the diversity of their pulsotypes, collection years, health care setting origins, and geographic areas of origination. All four isolates had tetB and overexpressed adeABC, as revealed by quantitative reverse transcription-PCR. Among all minocycline-based regimens, only the combination with colistin produced a fractional inhibitory concentration index comparable to that achieved with meropenem combined with colistin. Minocycline (4 or 16 μg/ml) in combination with colistin (0.5 μg/ml) also synergistically killed minocycline-resistant isolates in time-kill studies. Minocycline (50 mg/kg of body weight) in combination with colistin (10 mg/kg) significantly improved the survival of mice and reduced the number of bacteria present in the lungs of mice compared to the results of monotherapy. However, minocycline (16 μg/ml)-based therapy was not effective at reducing biofilm-associated bacteria at 24 or 48 h when its effectiveness was compared to that of colistin (0.5 μg/ml) and meropenem (8 μg/ml). The clinical use of

  3. 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

  4. Detecting imipenem resistance in Acinetobacter baumannii by automated systems (BD Phoenix, Microscan WalkAway, Vitek 2); high error rates with Microscan WalkAway

    OpenAIRE

    Ozlu Nagihan; Comert Fusun; Aktas Elif; Kulah Canan; Akyar Isin; Ankarali Handan

    2009-01-01

    Abstract Background Increasing reports of carbapenem resistant Acinetobacter baumannii infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility testing methods for testing the imipenem susceptibilities of A. baumannii isolates, by comp...

  5. MULTI DRUG RESISTANT ACINETOBACTER BAUMANNII: A SYSTEMATIC REVIEW FOR MICROBIAL AND CLINICAL STUDY

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    Buddha Bahadur Basnet

    2013-04-01

    Full Text Available Infections due to Mutli Drug Resistant A. baumannii (MDRAB is now recognized as a major public health problem worldwide. The nosocomial infection due to MDRAB has leaded to increased in morbidity and mortality which has added noticeably to significant challenge to modern antibiotic therapy system. This is due to rapid phenomenon of A. baumannii to acquire antibiotic resistance. Thus, in this review the overview of current knowledge on epidemiology, infections, mechanism of resistance and effective treatment options are briefly highlighted.

  6. 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.

  7. 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

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

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    Beieler Alison M

    2009-02-01

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

  9. 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.

  10. 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.

  11. 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

  12. 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

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

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    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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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...

  1. 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)

  2. Association between β-Lactamase-Encoding blaOXA-51 Variants and DiversiLab Rep-PCR-Based Typing of Acinetobacter baumannii Isolates

    Science.gov (United States)

    Zander, Esther; Nemec, Alexandr; Seifert, Harald

    2012-01-01

    This study investigated the correlation between blaOXA-51 variants and Acinetobacter baumannii worldwide clonal lineages 1 to 8 (WW1 to -8). The blaOXA-51-like genes of 102 A. baumannii isolates were sequenced. Using DiversiLab repetitive-sequence-based PCR (rep-PCR) typing, 92 of these isolates had previously been assigned to WW1 to -8 and 10 were unclustered. Clustering of DNA sequences was performed using the neighbor-joining method and the Jukes-Cantor phylogenetic correction. blaOXA-51 variants were in good correlation with DiversiLab-defined clonal lineages. Sequence-based typing of blaOXA-51 variants has the potential to be applied for epidemiologic characterization of A. baumannii and to identify worldwide clonal lineages 1 to 8. PMID:22422849

  3. Acinetobacter baumannii Infection in Prior ICU Bed Occupants Is an Independent Risk Factor for Subsequent Cases of Ventilator-Associated Pneumonia

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    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.

  4. Rapid molecular characterization of Acinetobacter baumannii clones with rep-PCR and evaluation of carbapenemase genes by new multiplex PCR in Hospital District of Helsinki and Uusimaa.

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    Tanja Pasanen

    Full Text Available Multidrug-resistant Acinetobacter baumannii (MDRAB is an increasing problem worldwide. Prevalence of carbapenem resistance in Acinetobacter spp. due to acquired carbapenemase genes is not known in Finland. The purpose of this study was to examine prevalence and clonal spread of multiresistant A. baumannii group species, and their carbapenemase genes. A total of 55 Acinetobacter isolates were evaluated with repetitive PCR (DiversiLab to analyse clonality of isolates, in conjunction with antimicrobial susceptibility profile for ampicillin/sulbactam, colistin, imipenem, meropenem, rifampicin and tigecycline. In addition, a new real-time PCR assay, detecting most clinically important carbapenemase genes just in two multiplex reactions, was developed. The assay detects genes for KPC, VIM, IMP, GES-1/-10, OXA-48, NDM, GIM-1, SPM-1, IMI/NMC-A, SME, CMY-10, SFC-1, SIM-1, OXA-23-like, OXA-24/40-like, OXA-58 and ISAbaI-OXA-51-like junction, and allows confident detection of isolates harbouring acquired carbapenemase genes. There was a time-dependent, clonal spread of multiresistant A. baumannii strongly correlating with carbapenamase gene profile, at least in this geographically restricted study material. The new carbapenemase screening assay was able to detect all the genes correctly suggesting it might be suitable for epidemiologic screening purposes in clinical laboratories.

  5. Clinical importance and cost of bacteremia caused by nosocomial multi drug resistant acinetobacter baumannii

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    Tugba Arslan Gulen

    2015-09-01

    Conclusion: Our results suggest that the occurrence of MDR A.baumannii bacteremia was related with the usage of the wide spectrum antibiotics, and mortality rates were increased in patients that high SAPS II scores, long term hospitalization. Infection control procedures and limited antibiotic usage are very important for prevent nosocomial infections.

  6. Carbapenemase genotypes of imipenem-resistant Acinetobacter baumannii strains%耐亚胺培南鲍氏不动杆菌碳青霉烯酶的基因型研究

    Institute of Scientific and Technical Information of China (English)

    陈亮; 李真; 刘颖

    2014-01-01

    目的 分析对亚胺培南耐药鲍氏不动杆菌的碳青霉烯酶基因型.方法 收集北京市积水潭医院临床样本中分离的对亚胺培南耐药的鲍氏不动杆菌48株,用琼脂稀释法测定菌株对7种抗生素的最低抑菌浓度(MIC);用PCR方法测定OXA-23类、OXA-24类、OXA-51类和OXA-58类基因及VIM、IMP基因,对扩增阳性的碳青酶烯酶基因进行测序分析.结果 48株鲍氏不动杆菌中,来自呼吸病房24株,急诊监护室12株,ICU7株,其他科室5株.来源于呼吸道样本的有42株.48株鲍氏不动杆菌OXA-23基因阳性45株,占93.8%,OXA-51基因全部阳性.OXA-58、OXA-24、VIM、IMP基因未检出.所测菌株对多黏菌素E敏感性最高,达到87.5%,但对环丙沙星、头孢他啶、庆大霉素、头孢哌酮/舒巴坦和哌拉西林/他唑巴坦的耐药率均高于90.0%.结论 OXA-51基因在鲍氏不动杆菌中广泛存在.OXA-23是该院耐亚胺培南的鲍氏不动杆菌中携带的主要的碳青霉烯酶基因型.%Objective To investigate the carbapenemase genotypes of imipenem-resistant Acinetobacter baumannii.Methods A total of 48 imipenem-resistant Acinetobacter baumanii strains were isolated from Jishuitan Hospital.The minimum inhibitory concentrations (MICs) of isolates to 7 antimicrobial agents were determined by agar dilution.The genes of OXA-23,OXA-24,OXA-51,OXA-58,VIM-type and IMP-type carbapenamases were determined by PCR.Amplified positive carbapenamase genes were analyzed by DNA sequencing.Results Of 48 Acinetobacter baumannii strains,24 were isolated from patients in respiratory ward,12 were isolated from patients in emergency intensive care unit,7 were isolated from patients in ICU,and 5 were isolated from patients in other departments; 42 were isolated from respiratory tract samples.There were 45 OXA-23 positive isolates(93.8%) and 48 OXA-51 positive isolates.OXA-58,OXA-24,VIM and IMP genes were not detected among the isolates.The Acinetobacter baumannii strains

  7. An Investigation of Antibacterial Resistance Patterns Among Acinetobacter baumannii and Pseudomonas aeruginosa Isolates Collected from Intensive Care Units of a University-Affiliated Hospital in Ahvaz, Iran

    Science.gov (United States)

    Izadpour, Farrokh; Ranjbari, Nastaran; Aramesh, Mohammad-Reza; Moosavian, Mojtaba; ShahAli, Shiva; Larki, Farzaneh; Tabesh, Hamed; Morvaridi, Afrooz

    2016-01-01

    Background In recent decades, multidrug-resistant non-fermenting Gram-negative pathogens, particularly Acinetobacter baumannii and Pseudomonas aeruginosa, have been recognized as a major cause of healthcare-associated and nosocomial infections and outbreaks. Objectives The aim of this study was to determine the prevalence and pattern of antibiotic resistance in A. baumannii and P. aeruginosa isolates collected from intensive care units (ICUs). Methods One hundred fifty-five clinical isolates, including 80 (51.6%) isolates of A. baumannii and 75 (48.4%) isolates of P. aeruginosa, from hospitalized patients in the ICUs of a teaching hospital in Ahvaz, Iran, were collected from January 1 to December 30, 2013. The organisms were identified with conventional bacteriological methods, and antimicrobial susceptibility testing was performed on all isolates in accordance with clinical laboratory and standards institute (CLSI) guidelines. Results The maximum resistance rates among A. baumannii isolates were observed for ciprofloxacin and trimethoprim-sulfamethoxazole (96.9% and 95.2%, respectively). For P. aeruginosa isolates, the maximum resistance rates were reported for ceftriaxone and trimethoprim-sulfamethoxazole (97.2% and 92.4%, respectively). Conclusions The majority of A. baumannii and P. aeruginosa isolates were found to be resistant to commonly recommended antibiotics. Therefore, surveillance of antibiotic consumption and proper antibiotic administration guidelines are essential for preventing major outbreaks in the future. PMID:27800136

  8. The Role of the Two-Component System BaeSR in Disposing Chemicals through Regulating Transporter Systems in Acinetobacter baumannii.

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    Ming-Feng Lin

    Full Text Available Bacterial two-component regulatory systems (TCSs facilitate changes in gene expression in response to environmental stimuli. TCS BaeR regulons influence tigecycline susceptibility in Acinetobacter baumannii through positively regulating the pump genes adeA and adeB. In this study, we demonstrate that an additional two transport systems, AdeIJK and MacAB-TolC, are also regulated by BaeSR. In the wild type and clinical tigecycline-resistant A. baumannii strains, gene expression of AdeIJK and MacAB-TolC increased after tigecycline induction, implicating their importance to tigecycline resistance in addition to AdeABC. Phenotypic microarray results showed that A. baumannii is vulnerable to certain chemicals, especially tannic acid, after deleting baeR, which was confirmed using the spot assay. The wild-type strain of A. baumannii also exhibited 1.6-fold and 4.4-fold increase in gene expression of adeJ and macB in the medium with 100 μg/mL tannic acid, but the increase was fully inhibited by baeR deletion. An electrophoretic motility shift assay based on an interaction between His-BaeR and the adeA, adeI and macA promoter regions did not demonstrate direct binding. In conclusion, A. baumannii can use the TCS BaeSR in disposing chemicals, such as tannic acid and tigecycline, through regulating the efflux pumps.

  9. Minocycline activity tested against Acinetobacter baumannii complex, Stenotrophomonas maltophilia, and Burkholderia cepacia species complex isolates from a global surveillance program (2013).

    Science.gov (United States)

    Flamm, Robert K; Castanheira, Mariana; Streit, Jennifer M; Jones, Ronald N

    2016-07-01

    Clinical isolates of Acinetobacter baumannii complex (1312), Stenotrophomonas maltophilia (464), and Burkholderia cepacia species complex (30) were selected from medical centers in the United States (USA), Europe and the Mediterranean (EU-M) region, Latin America, and Asia Pacific. Only one isolate per infected patient episode was included and local identifications were confirmed by the monitoring laboratory. Susceptibility testing was performed at the monitoring laboratory using the reference broth microdilution method as described by Clinical and Laboratory Standards Institute (CLSI). A. baumannii complex were classified as MDR (multi-drug resistant [MDR]; nonsusceptible to ≥1 agent in ≥3 antimicrobial classes) and extensively drug-resistant (XDR; nonsusceptible to ≥1 agent in all but ≤2 antimicrobial classes). A total of 81.6% of A. baumannii complex were MDR. Colistin was the most active agent against MDR A. baumannii complex. Minocycline was the most active "tetracycline" against these organisms based on susceptibility. Against B. cepacia, trimethoprim-sulfamethoxazole (MIC90, 2 μg/mL; 100.0% susceptible) was the most active agent tested. Overall, minocycline was the most active tetracycline tested against A. baumannii complex and S. maltophilia isolates collected from patients throughout EU-M, USA, Latin America, and the Asia-Pacific. Minocycline, particularly the intravenous formulation, has activity against several ESKAPE pathogens and merits consideration in seriously ill patients where treatment options may be limited due to the presence of MDR bacteria. PMID:27112832

  10. 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

  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. Antimicrobial Combinations against Pan-Resistant Acinetobacter baumannii Isolates with Different Resistance Mechanisms.

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    Gleice Cristina Leite

    Full Text Available The study investigated the effect of antibiotic combinations against 20 clinical isolates of A. baumannii (seven colistin-resistant and 13 colistin-susceptible with different resistance mechanisms. Clinical data, treatment, and patient mortality were evaluated. The following methods were used: MIC, PCRs, and outer membrane protein (OMP analysis. Synergy was investigated using the checkerboard and time-kill methods. Clonality was evaluated by PFGE. Based on clonality, the whole genome sequence of six A. baumannii isolates was analyzed. All isolates were resistant to meropenem, rifampicin, and fosfomycin. OXA-23 and OXA-143 were the most frequent carbapenemases found. Four isolates showed loss of a 43kDa OMP. The colistin-susceptible isolates belonged to different clones and showed the highest synergistic effect with fosfomycin-amikacin. Among colistin-resistant isolates, the highest synergistic effect was observed with the combinations of colistin-rifampicin followed by colistin-vancomycin. All colistin-resistant isolates harbored blaOXA-23-like and belonged to CC113. Clinical and demographic data were available for 18 of 20 patients. Fourteen received treatment and eight patients died during treatment. The most frequent site of infection was the blood in 13 of 14 patients. Seven patients received vancomycin plus an active drug against A. baumannii; however, mortality did not differ in this group. The synergistic effect was similar for colistin-susceptible isolates of distinct clonal origin presenting with the same resistance mechanism. Overall mortality and death during treatment was high, and despite the high synergism in vitro with vancomycin, death did not differ comparing the use or not of vancomycin plus an active drug against A. baumannii.

  13. 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

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

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    Li Jian

    2011-04-01

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

  15. Epidemiology and resistance features of Acinetobacter baumannii isolates from the ward environment and patients in the burn ICU of a Chinese hospital.

    Science.gov (United States)

    Gong, Yali; Shen, Xiaodong; Huang, Guangtao; Zhang, Cheng; Luo, Xiaoqiang; Yin, Supeng; Wang, Jing; Hu, Fuquan; Peng, Yizhi; Li, Ming

    2016-08-01

    Acinetobacter baumannii is an important opportunistic pathogen that causes severe nosocomial infections, especially in intensive care units (ICUs). Over the past decades, an everincreasing number of hospital outbreaks caused by A. baumannii have been reported worldwide. However, little attention has been directed toward the relationship between A. baumannii isolates from the ward environment and patients in the burn ICU. In this study, 88 A. baumannii isolates (26 from the ward environment and 62 from patients) were collected from the burn ICU of the Southwest Hospital in Chongqing, China, from July through December 2013. Antimicrobial susceptibility testing results showed that drug resistance was more severe in isolates from patients than from the ward environment, with all of the patient isolates being fully resistant to 10 out of 19 antimicrobials tested. Isolations from both the ward environment and patients possessed the β-lactamase genes bla OXA-51, bla OXA-23, bla AmpC, bla VIM, and bla PER. Using pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST), these isolates could be clustered into 4 major PFGE types and 4 main sequence types (ST368, ST369, ST195, and ST191) among which, ST368 was the dominant genotype. Epidemiologic and molecular typing data also revealed that a small-scale outbreak of A. baumannii infection was underway in the burn ICU of our hospital during the sampling period. These results suggest that dissemination of β-lactamase genes in the burn ICU might be closely associated with the high-level resistance of A. baumannii, and the ICU environment places these patients at a high risk for nosocomial infection. Cross-contamination should be an important concern in clinical activities to reduce hospitalacquired infections caused by A. baumannii. PMID:27480635

  16. CHINET 2010 surveillance of antibiotic resistance in Acinetobacter baumannii in China%2010年中国CHINET鲍曼不动杆菌耐药性监测

    Institute of Scientific and Technical Information of China (English)

    习慧明; 艾效曼; 张泓; 李万华; 贾蓓; 黄文祥; 王传清; 王爱敏; 魏莲花; 吴玲; 卓超; 徐英春; 苏丹虹; 张朝霞; 季萍; 徐元宏; 熊自忠; 沈继录; 单斌; 杜艳; 俞云松; 杨青; 朱德妹; 汪复; 倪语星; 孙景勇; 孙自镛; 简翠; 胡云建

    2012-01-01

    目的 了解2010年中国不同地区14所教学医院临床分离鲍曼不动杆菌的耐药性.方法 收集14所教学医院临床分离的非重复不动杆菌属共5 523株,其中鲍曼不动杆菌4 949株,按照统一方案,在各监测点采用纸片扩散法进行药敏试验,试验结果按照CLSI 2010年版标准判读,采用WHONET 5.4软件进行数据分析.结果 鲍曼不动杆菌对头孢哌酮-舒巴坦和米诺环素耐药率最低,分别为33.6%和35.4%.对碳青霉烯类抗生素亚胺培南和美罗培南的耐药率分别为62.1%和63.6%,对其他监测的抗菌药物的耐药率均达56.2%以上.不同医院分离菌对抗菌药物的耐药率不同,其中以ICU分离菌耐药率最高,急诊次之,内科最低.门诊与住院患者分离菌对亚胺培南和美罗培南的耐药率分别为48.3%/50.8%和62.3%/63.8%,且住院患者分离菌对抗菌药物的耐药率高于门诊患者(米诺环素除外).全国14所教学医院药敏试验结果显示多重耐药(MDR)及泛耐药(PDR)鲍曼不动杆菌分别达55.0%(2 720/4 949)和21.4%(1 058/4 949).2010年鲍曼不动杆菌耐药率与往年相比,呈上升趋势,尤以对头孢哌酮-舒巴坦、碳青霉烯类抗生素耐药率升高显著.结论 鲍曼不动杆菌对各抗菌药物的耐药性仍呈上升趋势.头孢哌酮-舒巴坦和米诺环素对鲍曼不动杆菌仍具有较好的体外抗菌活性.不同医院、不同科室鲍曼不动杆菌对抗菌药物的耐药率存在显著差异.%Objective To investigate the antimicrobial resistance in the strains of A. Baumannii isolated from patients in 14 hospitals in different cities all over china in 2010. Methods A total of 5 523 nondupiicate strains of Acinetobacter were collected from 14 hospitals in China, in which most were A. Baumannii (4 949, 89. 6%). Antimicrobial susceptibility testing was carried out by means of Kirby-Bauer method according to the unified protocol. The data were analyzed byWHONET 5. 4

  17. Clinical distribution and antimicrobial resistance of Acinetobacter bau-mannii isolated between 2011 and 2013%2011-2013年某院鲍曼不动杆菌临床分布与耐药性分析

    Institute of Scientific and Technical Information of China (English)

    童金英; 耿文娟; 王圆圆; 肖纯希; 杨咏梅; 田庆锷

    2015-01-01

    Objective To investigate the clinical distribution and change in antimicrobial resistance of Acinetobact-er baumannii (A.baumannii)from a hospital between 2011 and 2013,so as to provide guidance for clinical treat-ment.Methods Sources and antimicrobial susceptibility testing results of A.baumannii from a hospital were ana-lyzed statistically.Results A total of 14 705 bacterial isolates were isolated in 2011 —2013,13.59%(n=1 999)of which were A.baumannii isolates,the percentage of A.baumannii in isolated pathogens in 3 years was 12.74%, 13.05%,and 14.85% respectively,which showed a rising trend (χ2 =9.458,P =0.002).The main specimen was sputum (n = 1 541 ,77.09%),bacteria were mainly isolated from patients in respiratory disease department (21 .71 %),surgical intensive care unit (16.26%),and emergency intensive care unit (8.26%).Antimicrobial re-sistance rates of A.baumannii increased year by year(all P <0.05);multidrug-resistant and extensively drug-resist-ant A.baumannii also increased year by year (all P <0.001).Conclusion Isolation rate and antimicrobial resistance rate of A.baumannii strains increase year by year,multidrug-resistant and extensively drug-resistant A.baumannii strains are obvious,which should be paid more attention in clinical department.%目的:了解2011—2013年某院鲍曼不动杆菌的临床分布与耐药性变化趋势,为指导临床合理使用抗菌药物提供依据。方法对该院2011年1月—2013年12月分离的鲍曼不动杆菌来源和药敏试验结果进行统计分析。结果2011—2013年共分离细菌14705株,其中鲍曼不动杆菌1999株(13.59%),3年鲍曼不动杆菌分别占分离病原菌的12.74%、13.05%、14.85%,呈逐年上升趋势(χ2=9.458,P =0.002)。标本来源主要为痰(1541株,77.09%),分离科室以呼吸内科、外科重症监护室(SICU)和急诊重症监护室(EICU)为主,分别占21.71%、16.26%和8.26%。鲍曼

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

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    Purti C Tripathi

    2014-01-01

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

  19. Evaluation of the antibacterial effect of Echium amoenum Fisch. et Mey. against multidrug resistant Acinetobacter baumannii strains isolated from burn wound infection

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    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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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...

  5. 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...

  6. In vitro efficacy of copper and silver ions in eradicating Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii: implications for on-site disinfection for hospital infection control.

    Science.gov (United States)

    Huang, Hsin-I; Shih, Hsiu-Yun; Lee, Chien-Ming; Yang, Thomas C; Lay, Jiunn-Jyi; Lin, Yusen E

    2008-01-01

    Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter baumannii are major opportunistic waterborne pathogens causing hospital-acquired infections. Copper-silver ionization has been shown to be effective in controlling Legionella colonization in hospital water systems. The objective was to determine the efficacy of copper and silver ions alone and in combination in eradicating P. aeruginosa, S. maltophilia and A. baumannii at the concentration applied to Legionella control. Kill curve experiments and mathematical modeling were conducted at copper and silver ion concentrations of 0.1, 0.2, 0.4, 0.8 and 0.01, 0.02, 0.04, 0.08 mg/L, respectively. The combinations of copper and silver ions were tested at concentrations of 0.2/0.02 and 0.4/0.04 mg/L, respectively. Initial organism concentration was ca. of 3 x 10(6)cfu/mL, and viability of the test organisms was assessed at predetermined time intervals. Samples (0.1 mL) withdrawn were mixed with 10 microL neutralizer solution immediately, serially diluted and plated in duplicate onto blood agar plates. The culture plates were incubated for 48 h at 37 degrees C and enumerated for the cfu (detection limit 10 cfu/mL). The results showed all copper ion concentrations tested (0.1-0.8 mg/L) achieved more than 99.999% reduction of P. aeruginosa which appears to be more susceptible to copper ions than S. maltophilia and A. baumannii. Silver ions concentration of 0.08 mg/L achieved more than 99.999% reduction of P. aeruginosa, S. maltophilia and A. baumannii in 6, 12 and 96 h, respectively. Combination of copper and silver ions exhibited a synergistic effect against P. aeruginosa and A. baumannii while the combination exhibited an antagonistic effect against S. maltophilia. Ionization may have a potential to eradicate P. aeruginosa, S. maltophilia and A. baumannii from hospital water systems.

  7. Complete Sequence of pABTJ2, A Plasmid from Acinetobacter baumannii MDR-TJ, Carrying Many Phage-like Elements

    Institute of Scientific and Technical Information of China (English)

    He Huang; Yan Dong; Zhi-Liang Yang; Hao Luo; Xi Zhang; Feng Gao

    2014-01-01

    Acinetobacter baumannii is an important opportunistic pathogen in hospital, and the multidrug-resistant isolates of A. baumannii have been increasingly reported in recent years. A num-ber of different mechanisms of resistance have been reported, some of which are associated with plasmid-mediated acquisition of genes. Therefore, studies on plasmids in A. baumannii have been a hot issue lately. We have performed complete genome sequencing of A. baumannii MDR-TJ, which is a multidrug-resistant isolate. Finalizing the remaining large scaffold of the previous assem-bly, we found a new plasmid pABTJ2, which carries many phage-like elements. The plasmid pAB-TJ2 is a circular double-stranded DNA molecule, which is 110,967 bp in length. We annotated 125 CDSs from pABTJ2 using IMG ER and ZCURVE_V, accounting for 88.28%of the whole plasmid sequence. Many phage-like elements and a tRNA-coding gene were detected in pABTJ2, which is rarely reported among A. baumannii. The tRNA gene is specific for asparagine codon GTT, which may be a small chromosomal sequence picked up through incorrect excision during plasmid forma-tion. The phage-like elements may have been acquired during the integration process, as the GC content of the region carrying phage-like elements was higher than that of the adjacent regions. The finding of phage-like elements and tRNA-coding gene in pABTJ2 may provide a novel insight into the study of A. baumannii pan-plasmidome.

  8. Identification of Variable-Number Tandem-Repeat (VNTR) Sequences in Acinetobacter baumannii and Interlaboratory Validation of an Optimized Multiple-Locus VNTR Analysis Typing Scheme▿†

    Science.gov (United States)

    Pourcel, Christine; Minandri, Fabrizia; Hauck, Yolande; D'Arezzo, Silvia; Imperi, Francesco; Vergnaud, Gilles; Visca, Paolo

    2011-01-01

    Acinetobacter baumannii is an important opportunistic pathogen responsible for nosocomial outbreaks, mostly occurring in intensive care units. Due to the multiplicity of infection sources, reliable molecular fingerprinting techniques are needed to establish epidemiological correlations among A. baumannii isolates. Multiple-locus variable-number tandem-repeat analysis (MLVA) has proven to be a fast, reliable, and cost-effective typing method for several bacterial species. In this study, an MLVA assay compatible with simple PCR- and agarose gel-based electrophoresis steps as well as with high-throughput automated methods was developed for A. baumannii typing. Preliminarily, 10 potential polymorphic variable-number tandem repeats (VNTRs) were identified upon bioinformatic screening of six annotated genome sequences of A. baumannii. A collection of 7 reference strains plus 18 well-characterized isolates, including unique types and representatives of the three international A. baumannii lineages, was then evaluated in a two-center study aimed at validating the MLVA assay and comparing it with other genotyping assays, namely, macrorestriction analysis with pulsed-field gel electrophoresis (PFGE) and PCR-based sequence group (SG) profiling. The results showed that MLVA can discriminate between isolates with identical PFGE types and SG profiles. A panel of eight VNTR markers was selected, all showing the ability to be amplified and good amounts of polymorphism in the majority of strains. Independently generated MLVA profiles, composed of an ordered string of allele numbers corresponding to the number of repeats at each VNTR locus, were concordant between centers. Typeability, reproducibility, stability, discriminatory power, and epidemiological concordance were excellent. A database containing information and MLVA profiles for several A. baumannii strains is available from http://mlva.u-psud.fr/. PMID:21147956

  9. 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...

  10. Isolation, identification and diesel-oil biodegradation capacities of indigenous hydrocarbon-degrading strains of Cellulosimicrobium cellulans and Acinetobacter baumannii from tarball at Terengganu beach, Malaysia.

    Science.gov (United States)

    Nkem, Bruno Martins; Halimoon, Normala; Yusoff, Fatimah Md; Johari, Wan Lufti Wan; Zakaria, Mohamad Pauzi; Medipally, Srikanth Reddy; Kannan, Narayanan

    2016-06-15

    In this study, we isolated two indigenous hydrocarbon-degrading bacteria from tarball found in Rhu Sepuluh beach, Terengganu, Malaysia. These bacteria were identified based on their physiological characteristic and 16S rRNA gene sequence analysis, and they showed 99% similarity with Cellulosimicrobium cellulans DSM 43879 and Acinetobacter baumannii ATCC 19606 respectively. Their hydrocarbon-degrading capabilities were tested using diesel-oil as sole carbon source. Results analysed using GC-MS, showed diesel-oil alkanes were degraded an average 64.4% by C. cellulans and 58.1% by A. baumannii with medium optical density reaching 0.967 (C. cellulans) and 1.515 (A. baumannii) in minimal salt media at 32°C for 10days. Individual diesel-oil alkanes were degraded between 10%-95.4% by C. cellulans and 0.2%-95.9% by A. baumannii. Both strains utilized diesel-oil for growth. The study suggests both strains are part of indigenous hydrocarbon-degrading bacteria in tarball with potential for bioremediation of oil-polluted marine environment. PMID:27085593

  11. Investigation of a possible outbreak of carbapenem-resistant Acinetobacter baumannii in Odense, Denmark using PFGE, MLST and whole-genome-based SNPs

    DEFF Research Database (Denmark)

    Hammerum, Anette M.; Hansen, Frank; Skov, Marianne N.;

    2015-01-01

    OBJECTIVES: The objectives were to study a possible outbreak of carbapenem-resistant Acinetobacter baumannii by comparing three different typing methods (PFGE, MLST and whole-genome SNPs) and to compare the resistance gene profiles of the isolates. METHODS: From December 2012 to October 2013, eight...... carbapenem-resistant A. baumannii were detected at Odense University Hospital, Odense, Denmark. These isolates were typed by PFGE, with ApaI and SmaI, respectively, and subjected to WGS. The WGS data were used for in silico extraction of MLST types using two different schemes, resistance genes and SNPs...... in three distinct clusters. The two remaining isolates did not cluster with other Danish or international isolates included in the study. Isolates that clustered using PFGE, Oxford MLST and phylogenetic analysis also shared similar resistance gene profiles. CONCLUSIONS: The SNP profile, Oxford MLST, PFGE...

  12. Tandem Mass Spectrometry Detection of Quorum Sensing Activity in Multidrug Resistant Clinical Isolate Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Kok-Gan Chan

    2014-01-01

    Full Text Available Many Proteobacteria communicate via production followed by response of quorum sensing molecules, namely, N-acyl homoserine lactones (AHLs. These molecules consist of a lactone moiety with N-acyl side chain with various chain lengths and degrees of saturation at C-3 position. AHL-dependent QS is often associated with regulation of diverse bacterial phenotypes including the expression of virulence factors. With the use of biosensor and high resolution liquid chromatography tandem mass spectrometry, the AHL production of clinical isolate A. baumannii 4KT was studied. Production of short chain AHL, namely, N-hexanoyl-homoserine lactone (C6-HSL and N-octanoyl-homoserine lactone (C8-HSL, was detected.

  13. 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

  14. 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...

  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. 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.

  17. 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

  18. 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.

  19. 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.

  20. Correlation of the antiseptic resistance in Acinetobacter baumannii and the antiseptic resistance gene qacE△ 1 located in class Ⅰ integron

    Institute of Scientific and Technical Information of China (English)

    WEI FENG SHI; JIAN PING QIN; NING XU

    2006-01-01

    In the past decade, uses of antiseptics and disinfectants in hospitals and other health care centers are rather common, but the chance to develop resistance to antiseptics and disinfectants is also increased. Acinetobacter baumannii is one of the opportunistic bacteria involving in the nosocomial infection. In the present study, the correlation of the antiseptic resistance in A. baumannii and the antiseptic resistance gene qacE△1 was investigated by means of determination of MICs. Meanwhile, the MICs of glutaraldehyde, chlorhexidine, benzalkonium bromide, iodophor and trichloroisocyanurate to 80 clinical isolates of A. baumannii were detected by tube dilution assay and the resistance genes intI1 and qacE △ 1 in these isolates were amplified by PCR and verified by DNA sequencer. It was found that the MIC50 for these 5 antiseptics tested were 32, 8, 8, 4 and 1 μg/ml respectively, and the detection rates of intI1 and qacE△1 gene were 60.0% and 77.6% respectively. In addition, 55% of the 80 isolates simultaneously possessed both intI1 and qacE△ 1 gene, and the percentage of antiseptic resistance of A. baumannii carring both genes to benzalkonium bromide were higher than that without these two genes, however, there was no significant difference between intI1 and qacE△1 gene. The result in bactericidal efficiency assay indicated that chlorhexidine could still produce rapid and strong bactericidal effect at concentration of 1 MIC after 10 min exposure. These results suggest that the antiseptic resistance of A. baumannii to various antiseptics is correlated with the presence of the antiseptic resistance genes qacE△1 in bacteria, thus warning that the increase of the antiseptic resistance should not be ignored and the relative high concentration or prolonged application time is required to achieve a sufficient bactericidal effect.

  1. An Amphipathic Undecapeptide with All d-Amino Acids Shows Promising Activity against Colistin-Resistant Strains of Acinetobacter baumannii and a Dual Mode of Action.

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    Oddo, Alberto; Thomsen, Thomas T; Kjelstrup, Susanne; Gorey, Ciara; Franzyk, Henrik; Frimodt-Møller, Niels; Løbner-Olesen, Anders; Hansen, Paul R

    2016-01-01

    Multiple strains of Acinetobacter baumannii have developed multidrug resistance (MDR), leaving colistin as the only effective treatment. The cecropin-α-melittin hybrid BP100 (KKLFKKILKYL-NH2) and its analogs have previously shown activity against a wide array of plant and human pathogens. In this study, we investigated the in vitro antibacterial activities of 18 BP100 analogs (four known and 14 new) against the MDR A. baumannii strain ATCC BAA-1605, as well as against a number of other clinically relevant human pathogens. Selected peptides were further evaluated against strains of A. baumannii that acquired resistance to colistin due to mutations of the lpxC, lpxD, pmrA, and pmrB genes. The novel analogue BP214 showed antimicrobial activity at 1 to 2 μM and a hemolytic 50% effective concentration (EC50) of >150 μM. The lower activity of its enantiomer suggests a dual, specific and nonspecific mode of action. Interestingly, colistin behaved antagonistically to BP214 when pmrAB and lpxC mutants were challenged. PMID:26574005

  2. Antimicrobial Resistance Patterns of Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus Isolated From Patients With Nosocomial Infections Admitted to Tehran Hospitals

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    Fallah

    1970-01-01

    Full Text Available Background Nosocomial infections constitute a global health problem, leading to a high rate of morbidity and mortality. The choice of antimicrobial treatment for nosocomial infections is often empirical and based on the knowledge of local antimicrobial activity patterns of the most common bacteria causing such infections. Objectives The aim of this study was to determine the 3 most prevalent bacterial pathogens including Acinetobacter baumannii, Pseudomonas aeruginosa and Staphylococcus aureus causing nosocomial infections and their antimicrobial resistant profiles in patients admitted to three hospitals in Tehran city, Iran. Materials and Methods In this cross-sectional study, the A. baumannii, P. aeruginosa and S. aureus isolates were obtained from different samples of patients with nosocomial infections admitted to different wards of three hospitals including Milad, Motahary and Loghman from November 2014 to April 2015. Nosocomial infections were defined as a culture-proven infection, which occurred more than 48 hours after admission. Antimicrobial susceptibility testing was performed using the disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI guidelines. Results In total, 539 samples were collected during the study period from patients with nosocomial infections. Overall, 198, 75 and 98 A. baumannii, P. aeruginosa and S. aureus isolates were obtained, respectively. Cefepim and meropenem were found to be the most effective antibiotics for nosocomial infections caused by S. aureus with only 1 resistant isolate. Resistance to gentamicin and amikacin and susceptibility to cefepim was the highest compared to other antibiotics amongst P. aeruginosa isolates which is in consistent with the fact that cephalosporins remain useful agents for the management of nosocomial infections caused by P. aeruginosa. Acinetobacter baumannii isolates showed lower susceptibility rates to imipenem and ciprofloxacin than other

  3. Analysis on infection clinical distribution and drug resistance of acinetobacter baumannii%鲍曼不动杆菌感染的临床分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    罗祥文; 汤小燕

    2012-01-01

    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情况.方法 收集我院2007年7月至2010年7月的临床标本,进行鲍曼不动杆菌分离培养及药敏试验.结果 3年共分离出鲍曼不动杆菌373株,在临床标本中,痰液分布率最高,占78.6%,感染分布以ICU为主,占36.2%.药敏试验显示对碳青霉烯类、含酶抑制剂、多粘菌素E敏感性较高,对氨基糖苷类、喹诺酮类、β-内酰胺类耐药率较高,多重耐药性明显.结论 鲍曼不动杆菌主要侵犯ICU患者、慢性呼吸系统疾病患者及术后感染者.%Objective To investigate the infection clinical distribution and drug resistance of acinetobacter baumannii, and to offer an aid for clinical therapy and control of hospital-acquired infection. Methods The clinical specimens were collected from July 2007 to July 2010 for performing isolation, culture and sensitivity test to Acinetobacter baumannii. Results 373 strains of Acinetobacter baumannii were isolated in three years, whose dietribution was the highest in the sputum(78. 6% ). The infection distribution was major in the intensive care unit (ICU), accounting for 36. 2%. It was showed that the sensitive drugs of Acinetobacter baumannii were carbapenems.and inhibitor, polymyxin E.and resistant drugs of Acinetobacter baumannii were aminoglycosides,quinolones,and bets-lactamases. Moreover, these strains showed multi-drug resistance. Conclusion Acinetobacter baumannii mainly offended the patients in ICU and with chronic respiratory diseases and postoperative infection. Therefore, laboratories should be strengthened to analyze the resistant strains of Acinetobacter baumannii in wards, especially the ICU wards and drug sensitivity monitoring to provide relevant information in time, and antibiotics should be used rationally so as to enhance clinical therapeutic efficacy.

  4. 2012年中国CHINET不动杆菌属细菌耐药性监测%CHINET 2012 surveillance of antibiotic resistance in Acinetobacter baumannii isolates in China

    Institute of Scientific and Technical Information of China (English)

    张辉; 卓超; 苏丹虹; 褚云卓; 俞云松; 林洁; 徐元宏; 沈继录; 倪语星; 孙景勇; 张朝霞; 张小江; 季萍; 魏莲花; 吴玲; 王传清; 薛建昌; 张泓; 李万华; 胡云建; 艾效曼; 单斌; 徐英春; 杜艳; 胡志东; 李金; 孙自镛; 简翠; 汪复; 朱德妹

    2014-01-01

    .6 software according to CLSI 2013 breakpoints .Results Majority (85 .4% ) of the Acinetobacter strains were isolated from inpatients .The remaining 14 .6% were from outpatients and emergency room patients .Of the 7 827 strains of A .baumannii , 10 .9% ,35 .2% ,35 .7% and 43 .4% were resistant to tigecycline ,minocycline ,cefoperazone-sulbactam and amikacin , respectively .The percentage of A .baumannii resistant to imipenem and meropenem was 63 .5% and 68 .2% ,respectively . The antimicrobial resistant pattern varied in different hospitals . The resistance of A . baumannii varied between different clinical departments .A number of pandrug resistant (PDR) (20 .0% ,1 567/7 827) and multidrug-resistant (MDR) (45 .0% , 3 521/7 827 ) A . baumannii were identified . Conclusions A . baumannii is the most popular pathogenic bacteria among Acinetobacter .The antibiotic resistance of A .baumannii is still increasing .Cefoperazone-sulbactam and minocycline has good in vitro antibacterial activity against A .baumannii .The antibiotic resistance of A .baumannii varies greatly with hospital and department .

  5. Choice of antimicrobial agents for multidrug-resistant Acinetobacter baumannii infection in burns%烧伤患者耐药鲍曼不动杆菌感染的抗菌药物选择

    Institute of Scientific and Technical Information of China (English)

    黄晓琴; 郇京宁

    2012-01-01

    Multidrug-resistant Acinetobacter baumannii infection represents a growing problem in severe burns. The antimicrobial resistance mechanisms of Acinetobacter baumannii include an increasing arsenal of β-lactamases, altered expression of outer membrane protein, efflux pumps and biofilm formation. For Acinetobacter baumannii wound infection, silver sulfadiazine. sulfamylon and silver dressing are effective topical agents. The effective treatment with antibiotics in Acinetobacter baumannii sepsis involves polymyxins, sulbactam, minocycline and tigecycline, and the combination use of antibiotics is strongly recommended. Besides, some novel therapeutic agents for multidrug-resistant Acinetobacter baumannii are introduced in this paper.%耐药性鲍曼不动杆菌是严重烧伤感染的重要致病菌之一,其耐药机制与细菌产生多种β-内酰胺酶、膜药物通透性缺陷、药物外排系统和细菌生物膜形成等有关.针对烧伤创面鲍曼不动杆菌感染,磺胺嘧啶银霜、磺胺米隆溶液和银离子敷料是良好的局部外用药物.在耐药鲍曼不动杆菌脓毒症的治疗方面,可选择多黏菌素、舒巴坦、米诺环素和替加环素.但是,尤为重要的手段是联合应用抗生素.此外,该文还讨论了某些新型药物的抗耐药鲍曼不动杆菌的作用.

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

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    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. Detecting imipenem resistance in Acinetobacter baumannii by automated systems (BD Phoenix, Microscan WalkAway, Vitek 2; high error rates with Microscan WalkAway

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    Ozlu Nagihan

    2009-03-01

    Full Text Available Abstract Background Increasing reports of carbapenem resistant Acinetobacter baumannii infections are of serious concern. Reliable susceptibility testing results remains a critical issue for the clinical outcome. Automated systems are increasingly used for species identification and susceptibility testing. This study was organized to evaluate the accuracies of three widely used automated susceptibility testing methods for testing the imipenem susceptibilities of A. baumannii isolates, by comparing to the validated test methods. Methods Selected 112 clinical isolates of A. baumanii collected between January 2003 and May 2006 were tested to confirm imipenem susceptibility results. Strains were tested against imipenem by the reference broth microdilution (BMD, disk diffusion (DD, Etest, BD Phoenix, MicroScan WalkAway and Vitek 2 automated systems. Data were analysed by comparing the results from each test method to those produced by the reference BMD test. Results MicroScan performed true identification of all A. baumannii strains while Vitek 2 unidentified one strain, Phoenix unidentified two strains and misidentified two strains. Eighty seven of the strains (78% were resistant to imipenem by BMD. Etest, Vitek 2 and BD Phoenix produced acceptable error rates when tested against imipenem. Etest showed the best performance with only two minor errors (1.8%. Vitek 2 produced eight minor errors(7.2%. BD Phoenix produced three major errors (2.8%. DD produced two very major errors (1.8% (slightly higher (0.3% than the acceptable limit and three major errors (2.7%. MicroScan showed the worst performance in susceptibility testing with unacceptable error rates; 28 very major (25% and 50 minor errors (44.6%. Conclusion Reporting errors for A. baumannii against imipenem do exist in susceptibility testing systems. We suggest clinical laboratories using MicroScan system for routine use should consider using a second, independent antimicrobial susceptibility

  8. Análisis genómico del resistoma de la cepa de Acinetobacter baumannii ABIBUN 107m multi-resistente y persistente en hospitales colombianos

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    Maria Teresa Reguero

    2014-12-01

    Full Text Available Acinetobacter baumannii is a bacterium causing health care associated infections such as pneumonia, septicemia, meningitis and urinary infections amongst others. It has great capacity to quickly develop and gather a big variety of drug resistance mechanisms. In this research, the genome of strain A. baumannii ABIBUN 107m was analyzed wich forms part of a persistent clon in Colombian hospitals and it’s also resistant to carbapenems (imipenem and meropenem, which are the election antibiotics for treatment of infections caused by this microorganism. The genome was sequenced using high performance technology, assembled and annotated. As a result, we obtained a 3954000 bp genome, with 56 contigs; 4256 genes with average size of 912 bp; 3796 CDS; 2884 were assigned to COG; 57 tRNA and GC percentage of 38,74%. The A. baumannii strain ABIBUN 107m, is resistant to the following antibiotic groups: b-lactams, aminoglycosides, quinolones, tetracycline, sulfonamide and colistin. Genes associated with this resistance profile were found in A. baumannii ABIBUN 107m genome serino b-lactamases (blaADC-38, blaOXA-64, blaOXA-23, blaampC-like, blaamp(H-like, metallo b-lactamase_B; High Molecular Mass penicillin binding proteins, ISAba1 type insertion sequences, mutations of DNA gyrase and topoisomerase IV subunit A (gyrA and parC; aminoglycoside modifying enzymes (aphA-like, aadA-like; choramphenicol acyltransferase (cat and dehydropteroate synthase (sul-1. Genes belonging to five different efflux systems were identified (RND, MATE, MSF, ATP, SMR.

  9. Polymyxin B in Combination with Antimicrobials Lacking In Vitro Activity versus Polymyxin B in Monotherapy in Critically Ill Patients with Acinetobacter baumannii or Pseudomonas aeruginosa Infections.

    Science.gov (United States)

    Rigatto, Maria Helena; Vieira, Fabiane J; Antochevis, Laura C; Behle, Tainá F; Lopes, Natane T; Zavascki, Alexandre P

    2015-10-01

    There is no clinical evidence supporting the use of polymyxin B in combination with another antimicrobial for infections caused by extensively drug-resistant Acinetobacter baumannii or Pseudomonas aeruginosa isolates. We developed a cohort study of patients in two intensive care units from teaching hospitals to evaluate treatment with intravenous polymyxin B for ≥48 h for severe A. baumannii or P. aeruginosa infections. Covariates potentially associated with 30-day mortality were evaluated in a Cox proportional hazards model. A total of 101 patients were included; 33 (32.7%) were treated with polymyxin B in combination with an antimicrobial lacking in vitro activity and 68 (67.3%) with polymyxin B in monotherapy. The overall 30-day mortality was 59.4% (60 patients), comprising 42.4% (14 of 33) and 67.6% (46 of 68) in combination and monotherapy groups, respectively (P = 0.03). The mortality rates were 18.5/1,000 patient days and 36.4/1,000 patient days in the combination and monotherapy groups, respectively (P = 0.02). Combination therapy was independently associated with lower 30-day mortality (hazard ratio, 0.33; 95% confidence interval, 0.17 to 0.64; P = 0.001). Creatinine clearance of ≥60 ml/min was also a protective factor, while a higher acute physiology and chronic health evaluation (APACHE II) score and polymicrobial infection were associated with increased mortality. The results did not change after adding a propensity score for prescribing combination therapy into the model. The protective effect remained when only combination with β-lactam or carbapenem was considered and in both subgroups of patients: those with A. baumannii infection and those with lower respiratory tract infections. To our knowledge, this is the first clinical study to show a benefit of combination over monotherapy with polymyxin B for severe extensively drug-resistant A. baumannii or P. aeruginosa infections. PMID:26259799

  10. Toward repurposing ciclopirox as an antibiotic against drug-resistant Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae.

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    Kimberly M Carlson-Banning

    Full Text Available Antibiotic-resistant infections caused by gram-negative bacteria are a major healthcare concern. Repurposing drugs circumvents the time and money limitations associated with developing new antimicrobial agents needed to combat these antibiotic-resistant infections. Here we identified the off-patent antifungal agent, ciclopirox, as a candidate to repurpose for antibiotic use. To test the efficacy of ciclopirox against antibiotic-resistant pathogens, we used a curated collection of Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae clinical isolates that are representative of known antibiotic resistance phenotypes. We found that ciclopirox, at 5-15 µg/ml concentrations, inhibited bacterial growth regardless of the antibiotic resistance status. At these same concentrations, ciclopirox reduced growth of Pseudomonas aeruginosa clinical isolates, but some of these pathogens required higher ciclopirox concentrations to completely block growth. To determine how ciclopirox inhibits bacterial growth, we performed an overexpression screen in E. coli. This screen revealed that galE, which encodes UDP-glucose 4-epimerase, rescued bacterial growth at otherwise restrictive ciclopirox concentrations. We found that ciclopirox does not inhibit epimerization of UDP-galactose by purified E. coli GalE; however, ΔgalU, ΔgalE, ΔrfaI, or ΔrfaB mutant strains all have lower ciclopirox minimum inhibitory concentrations than the parent strain. The galU, galE, rfaI, and rfaB genes all encode enzymes that use UDP-galactose or UDP-glucose for galactose metabolism and lipopolysaccharide (LPS biosynthesis. Indeed, we found that ciclopirox altered LPS composition of an E. coli clinical isolate. Taken together, our data demonstrate that ciclopirox affects galactose metabolism and LPS biosynthesis, two pathways important for bacterial growth and virulence. The lack of any reported fungal resistance to ciclopirox in over twenty years of use in the clinic

  11. Screening a mushroom extract library for activity against Acinetobacter baumannii and Burkholderia cepacia and the identification of a compound with anti-Burkholderia activity

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    Rott Marc

    2010-01-01

    Full Text Available Abstract Background Acinetobacter baumannii and species within the Burkholderia cepacia complex (BCC are significant opportunistic bacterial pathogens of humans. These species exhibit a high degree of antibiotic resistance, and some clinical isolates are resistant to all currently available antimicrobial drugs used for treatment. Thus, new drugs are needed to treat infections by these species. Mushrooms could be a potential source for new drugs to treat A. baumannii and BCC infections. Methods The aim of this study was to screen a library of crude extracts from 330 wild mushrooms by disk diffusion assays for antibacterial activity against A. baumannii and Burkholderia cepacia in the hope of identifying a novel natural drug that could be used to treat infections caused by these species. Once positive hits were identified, the extracts were subjected to bioassay-guided separations to isolate and identify the active drug molecules. MICs were performed to gauge the in vitro activity of the purified compounds. Results Only three crude extracts (0.9% had activity against A. baumannii and B. cepacia. Compounds from two of these extracts had MICs greater than 128 μg/ml, and further analyses were not performed. From the third extract, prepared from Leucopaxillus albissimus, 2-aminoquinoline (2-AQ was isolated. This compound exhibited a modest MIC in vitro against strains from nine different BCC species, including multi-drug resistant clinical isolates (MIC = 8-64 μg/ml, and a weak MIC (128 μg/ml against A baumannii. The IC50 against a murine monocyte line was 1.5 mg/ml. Conclusion The small number of positive hits in this study suggests that finding a new drug from mushrooms to treat Gram-negative bacterial infections may be difficult. Although 2-AQ was identified in one mushroom, and it was shown to inhibit the growth of multi-drug resistant BCC isolates, the relatively high MICs (8-128 μg/ml for both A. baumannii and BCC strains suggests that 2-AQ

  12. Sources of multidrug-resistant Acinetobacter baumannii and its role in respiratory tract colonization and nosocomial pneumonia in intensive care unit patients

    Institute of Scientific and Technical Information of China (English)

    HUANG Jie; CHEN Er-zhen; QU Hong-ping; MAO En-qiang; ZHU Zheng-gang; NI Yu-xing; HAN Li-zhong

    2013-01-01

    Background Multidrug-resistant Acinetobacter baumannii (MDRAB) is an important and emerging hospital-acquired pathogen worldwide.This study was conducted to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia in intensive care unit (ICU) patients.Methods We conducted a prospective active surveillance study of MDRAB in three ICUs at a Chinese Hospital from April to August 2011,to identify the sources of MDRAB and its role in respiratory tract colonization and nosocomial pneumonia.Results One hundred and fourteen (13.0%) MDRAB isolates were detected from 876 specimens,with a sensitivity of 11.6% (55/474) in screening of the pharyngeal and tracheal swabs,and 14.7% (59/402) of the sputum/endotracheal aspirates.MDRAB colonization/infection was found in 34 (26.8%) of 127 patients,including 16 (12.6%) cases of pure colonization and 18 (14.2%) cases of pneumonia (two pre-ICU-acquired cases of pneumonia and 16 ICU-acquired cases of pneumonia).Previous respiratory tract MDRAB colonization was found in 22 (17.3%) patients:eight (6.3%)were pre-ICU-acquired colonization and 14 (11.0%) ICU-acquired colonization.Of eight pre-ICU-colonized patients,five were transferred from other wards or hospitals with hospitalization >72 hours,and three came from the community with no previous hospitalization.Overall,6/22 colonized patients presented with secondary pneumonia; only two (9.1%) colonized MDRAB strains were associated with secondary infections.Respiratory tract MDRAB colonization had no significant relationship with nosocomial pneumonia (P=-0.725).In addition,acute respiratory failure,mechanical ventilation,renal failure,and prior carbapenem use were risk factors for MDRAB colonization/infection.Conclusions A high proportion of cases of MDRAB colonization/infection in ICU patients were detected through screening cultures.About one-third were acquired from general wards and the community before ICU admission

  13. Determination of synergy between sulbactam, meropenem and colistin in carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii isolates and correlation with the molecular mechanism of resistance.

    Science.gov (United States)

    Laishram, Shakti; Anandan, Shalini; Devi, Bakthavatchalam Yamuna; Elakkiya, Munusamy; Priyanka, Babu; Bhuvaneshwari, Thukkaram; Peter, John Victor; Subramani, Kandasmy; Balaji, Veeraraghavan

    2016-08-01

    Treatment of infections with carbapenem-resistant Gram negative organism is a major challenge especially among intensive care patients. Combinations of sulbactam, meropenem and colistin was studied for its synergistic activity against 100 invasive isolates of carbapenem-resistant Klebsiella pneumoniae and Acinetobacter baumannii-calcoaceticus complex by checkerboard assay and time kill assay (TKA). In addition, presence of carbapenemase production was determined by multiplex PCR. Time kill assay detected more synergy than checkerboard assay. Good bactericidal activity of 70-100% was noted with the combinations tested. Among K. pneumoniae, isolates producing NDM carbapenemase alone showed significantly more synergy than isolates producing OXA-48-like carbapenemases. In treatment of infection with carbapenem-resistant organisms, the site of infection and the type of carbapenemase produced may help to determine the most effective combination of antimicrobials. PMID:27461479

  14. In vitro synergism of combinations of colistin with selected antibiotics against colistin-resistant Acinetobacter baumannii

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    Percin, Duygu

    2014-08-01

    Full Text Available [english] Aim: The in vitro activity of colistin in combination with sulbactam, netilmicin, and vancomycin against colistin-resistant strains was investigated. Furthermore, the clonal relationship of the strains was analyzed. Methods: Clonal relationship was investigated using rep-PCR. To screen for synergysm, the fractional inhibitory concentration index (FICI was calculated using checkerboard assay. The killing kinetics of the combination of colistin with vancomycin was assessed using time-kill assay. Results: Three different clones were found among 10 clinical isolates of colistin-resistant strains. Thereof, 8 strains were susceptible to netilmicin. Synergistic interaction was detected in 1 strain with the combination of colistin-netilmicin, in 5 strains with colistin-sulbactam, and in 9 strains with colistin-vancomycin. None of combinations had antagonistic activity. Colistin-vancomycin combination resulted in rapid bactericidal activity. Conclusion: These results show a distinct in vitro synergism between colistin and vancomycin, which might be useful to treat infection with multiple-resistant strains, prevent emergence of resistant strains, and to lower doses for both antibiotics to be used.

  15. 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/

  16. Isolation and characterization of φkm18p, a novel lytic phage with therapeutic potential against extensively drug resistant Acinetobacter baumannii.

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    Gwan-Han Shen

    Full Text Available AIMS: To isolate phages against extensively drug resistant Acinetobacter baumannii (XDRAB and characterize the highest lytic capability phage as a model to evaluate the potential on phage therapy. METHODS AND RESULTS: Eight phages were isolated from hospital sewage and showed narrow host spectrum. Phage φkm18p was able to effectively lyse the most XDRAB. It has a dsDNA genome of 45 kb in size and hexagonal head of about 59 nm in diameter and no tail. Bacterial population decreased quickly from 10(8 CFU ml(-1 to 10(3 CFU ml(-1 in 30 min by φkm18p. The 185 kDa lysis protein encoded by φkm18p genome was detected when the extracted protein did not boil before SDS-PAGE; it showed that the lysis protein is a complex rather than a monomer. Phage φkm18p improved human lung epithelial cells survival rates when they were incubated with A. baumannii. Combination of phages (φkm18p, φTZ1 and φ314 as a cocktail could lyse all genotype-varying XDRAB isolates. CONCLUSION: Infections with XDRAB are extremely difficult to treat and development of a phage cocktails therapy could be a therapeutic alternative in the future. Phage φkm18p is a good candidate for inclusion in phage cocktails.

  17. “Specificity Determinants” Improve Therapeutic Indices of Two Antimicrobial Peptides Piscidin 1 and Dermaseptin S4 Against the Gram-negative Pathogens Acinetobacter baumannii and Pseudomonas aeruginosa

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    Ziqing Jiang

    2014-03-01

    Full Text Available A new class of antimicrobial agents with lower rates of resistance and different targets is urgently needed because of the rapidly increasing resistance to classical antibiotics. Amphipathic cationic α-helical antimicrobial peptides (AMPs represent such a class of compounds. In our previous studies, using a 26-residue de novo designed antimicrobial peptide, we proposed the concept of “specificity determinant(s”: positively charged residue(s in the center of the non-polar face of AMPs that could decrease hemolytic activity/toxicity but increase or maintain the same level of antimicrobial activity to increase dramatically the therapeutic index. In the current study, we used d-enantiomers of two AMPs, Piscidin 1 isolated from fish and dermaseptin S4 isolated from frog. We substituted different positions in the center of the hydrophobic face with one or two lysine residue(s (one or two “specificity determinant(s”. This simple modification not only maintained or improved antimicrobial activity against Gram-negative pathogens Acinetobacter baumannii (11 strains and Pseudomonas aeruginosa (6 strains, but also dramatically decreased hemolytic activity of human red blood cells, as predicted. Therapeutic indices improved by 55-fold and 730-fold for piscidin 1 (I9K and dermaseptin S4 (L7K, A14K, respectively, against A. baumannii. Similarly, the therapeutic indices improved 32-fold and 980-fold for piscidin 1 (I9K and dermaseptin S4 (L7K, A14K, respectively, against P. aeruginosa.

  18. Differences in Biofilm Mass, Expression of Biofilm-Associated Genes, and Resistance to Desiccation between Epidemic and Sporadic Clones of Carbapenem-Resistant Acinetobacter baumannii Sequence Type 191

    Science.gov (United States)

    Selasi, Gati Noble; Nicholas, Asiimwe; Jeon, Hyejin; Na, Seok Hyeon; Kwon, Hyo Il; Kim, Yoo Jeong; Heo, Sang Taek; Oh, Man Hwan; Lee, Je Chul

    2016-01-01

    Understanding the biology behind the epidemicity and persistence of Acinetobacter baumannii in the hospital environment is critical to control outbreaks of infection. This study investigated the contributing factors to the epidemicity of carbapenem-resistant A. baumannii (CRAB) sequence type (ST) 191 by comparing the differences in biofilm formation, expression of biofilm-associated genes, and resistance to desiccation between major epidemic (n = 16), minor epidemic (n = 12), and sporadic (n = 12) clones. Biofilm mass was significantly greater in the major epidemic than the minor epidemic and sporadic clones. Major and minor epidemic clones expressed biofilm-associated genes, abaI, bap, pgaABCD, and csuA/BABCDE, higher than the sporadic clones in sessile conditions. The csuC, csuD, and csuE genes were more highly expressed in the major epidemic than minor epidemic clones. Interestingly, minor epidemic clones expressed more biofilm-associated genes than the major epidemic clone under planktonic conditions. Major epidemic clones were more resistant to desiccation than minor epidemic and sporadic clones on day 21. In conclusion, the epidemic CRAB ST191 clones exhibit a higher capacity to form biofilms, express the biofilm-associated genes under sessile conditions, and resist desiccation than sporadic clones. These phenotypic and genotypic characteristics of CRAB ST191 may account for the epidemicity of specific CRAB ST191 clones in the hospital. PMID:27622249

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

    Directory of Open Access Journals (Sweden)

    Praveen K. Sahu

    2012-01-01

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

  20. Differences in Biofilm Mass, Expression of Biofilm-Associated Genes, and Resistance to Desiccation between Epidemic and Sporadic Clones of Carbapenem-Resistant Acinetobacter baumannii Sequence Type 191.

    Science.gov (United States)

    Selasi, Gati Noble; Nicholas, Asiimwe; Jeon, Hyejin; Na, Seok Hyeon; Kwon, Hyo Il; Kim, Yoo Jeong; Heo, Sang Taek; Oh, Man Hwan; Lee, Je Chul

    2016-01-01

    Understanding the biology behind the epidemicity and persistence of Acinetobacter baumannii in the hospital environment is critical to control outbreaks of infection. This study investigated the contributing factors to the epidemicity of carbapenem-resistant A. baumannii (CRAB) sequence type (ST) 191 by comparing the differences in biofilm formation, expression of biofilm-associated genes, and resistance to desiccation between major epidemic (n = 16), minor epidemic (n = 12), and sporadic (n = 12) clones. Biofilm mass was significantly greater in the major epidemic than the minor epidemic and sporadic clones. Major and minor epidemic clones expressed biofilm-associated genes, abaI, bap, pgaABCD, and csuA/BABCDE, higher than the sporadic clones in sessile conditions. The csuC, csuD, and csuE genes were more highly expressed in the major epidemic than minor epidemic clones. Interestingly, minor epidemic clones expressed more biofilm-associated genes than the major epidemic clone under planktonic conditions. Major epidemic clones were more resistant to desiccation than minor epidemic and sporadic clones on day 21. In conclusion, the epidemic CRAB ST191 clones exhibit a higher capacity to form biofilms, express the biofilm-associated genes under sessile conditions, and resist desiccation than sporadic clones. These phenotypic and genotypic characteristics of CRAB ST191 may account for the epidemicity of specific CRAB ST191 clones in the hospital. PMID:27622249

  1. Study of the effect of essential oil of Salvia glutinosa L. on microbial biofilm formation by clinical isolates of Acinetobacter baumannii

    Science.gov (United States)

    Tutar, Uǧur

    2016-04-01

    Acinetobacter baumannii is becoming a serious concern in the treatment of infections that can develop resistance to many antibiotics. This persistence may be explained by its capacity to form biofilms. In our study, the essential oil (EO) of the Salvia glutinosa plant, was obtained through the hydrodistillation method. Antimicrobial and antibiofilm activities of the EO on the 20 multi-drug resistant (MDR) A.baumannii isolates were researched. Broth microdilution methods were applied for the determination of the antimicrobial activity. For the determined antibiofilm activity, the Minimal Biofilm Inhibition Concentration (MBIC) test was implemented with the microtiter plate method. Photometric assay was applied for the identification of the antioxidant capacity and colorimetric assay was used to specify the cytotoxicity of the EO of S. glutinosa on L929 cells. In our study, Minimal Inhibition Concentration (MIC) and Minimal Bactericidal Concentration (MBC) values between 1.25-2.5 µl/mL and 5-10 µl/mL respectively. MBIC value of the EO was found as 0.3-2.5 µl/mL. IC50= = 24.4±0.66 µl/mL was found as the antioxidant capacity of the EO. At 25%, 12.5% and 6.25% EO concentrations, no cytotoxicity appeared for the fibroblast cells in terms of the cytotoxic activities (p>0.05). According to the findings obtained in our study, antibiofilm, antimicrobial and antioxidant activities of the S. glutinosa EO seem remarkable. These findings seem promising for the development of potential phytotherapeutic agents in the treatment of the multi-drug resistance (MDR) A.baumannii infections.

  2. Effects of Group 1 versus Group 2 carbapenems on the susceptibility of Acinetobacter baumannii to carbapenems: a before and after intervention study of carbapenem-use stewardship.

    Directory of Open Access Journals (Sweden)

    Young Kyung Yoon

    Full Text Available OBJECTIVE: Antimicrobial stewardship programs have been proposed for reducing bacterial resistance in the hospital environment. The purpose of this study was to investigate the impact of a carbapenem-use stewardship program on the susceptibility of Acinetobacter baumannii to Group 2 carbapenems. METHODS: A before and after intervention study was conducted at a university hospital from September 2008 to February 2013. Three study periods were defined: Phase I, pre-intervention (months 1-18; Phase II, a postintervention period during which ertapenem use was mandated but carbapenem use was not restricted (months 19-36; and Phase III, a postintervention period during which Group 2 carbapenem use was restricted (months 37-54. RESULTS: During the study period, intervention resulted in diminished consumption of Group 2 carbapenems (antimicrobial use density (AUD: 21.3±6.0 in Phase I, 18.8±6.0 in Phase II, 16.1±4.4 in Phase III; P = 0.028 and increased consumption of ertapenem (AUD: 2.7±1.7 in Phase I, 7.2±4.5 in Phase II, 9.1±5.3 in Phase III; P<0.001. The use of autoregressive-error models showed that in contrast with ertapenem use, the use of Group 2 carbapenem during the previous one month was positively and significantly associated with a subsequent increase in the proportion of carbapenem-resistant A. baumannii (CRAB (P = 0.031. CONCLUSIONS: Implementing a carbapenem-use stewardship program featuring the preferential use of ertapenem for treating appropriate indications of infection resulted in reduced use of Group 2 carbapenems and had a positive impact on the susceptibility of A. baumannii to carbapenems. This approach could be integrated into CRAB-control strategies in hospitals.

  3. Insertion sequence disruption of adeR and ciprofloxacin resistance caused by efflux pumps and gyrA and parC mutations in Acinetobacter baumannii.

    Science.gov (United States)

    Lopes, B S; Amyes, S G B

    2013-02-01

    Acinetobacter baumannii is a pathogenic bacterium responsible for a wide range of infections in immunocompromised patients. This study examined the role of insertional inactivation of the adeR gene and its effect on adeABC gene expression along with characterisation of the gyrA and parC mutations involved in ciprofloxacin resistance in three A. baumannii clinical isolates and their derivatives. Primers designed for the detection of adeSRABC detected the presence of ISAba16, which disrupted the adeR gene in strain Ab12M, and ISAba1, which disrupted the same gene in strains Ab18 and Ab209. A second copy of ISAba1 was detected upstream of the adeA gene in Ab209 leading to AdeABC pump expression. AdeIJK pump expression was seen in all of the isolates but was not as significant as AdeABC expression. Minimum inhibitory concentrations of ciprofloxacin were ≥256 mg/L for all of the isolates and a decrease of ≥8-fold was seen following addition of the efflux pump inhibitor 1-(1-naphthylmethyl)-piperazine. Fluorometric analysis also demonstrated active efflux, with upregulation of adeIJK and some genes of the adeABC operon in some strains. Sequencing of the quinolone resistance-determining region of the gyrA and parC genes revealed a Ser83→Leu change in the gyrA gene and a novel change of Ser80→Trp in the parC gene of Ab12, Ab12M and Ab209; in Ab18 there was a Ser80→Leu change in parC. This study shows the multifactorial contribution of different mechanisms in A. baumannii leading to ciprofloxacin resistance. PMID:23217848

  4. ICU痰培养鲍曼不动杆菌耐药性变迁分析%Change of drugs resistance of Acinetobacter baumannii cultivated from sputum in ICU

    Institute of Scientific and Technical Information of China (English)

    曾慧; 陈淼; 游恩丽; 权明桃

    2012-01-01

    Objective To get knowledge of the drugs resistance change of Acinetobacter baumannii in ICU, so as to offer the first-hand information to the clinical preventive and therapeutic countermeasures. Methods Retrospective investigation was used to analyze Acinetobacter baumannii resistant bacteria changes of sputum culture results in our ICU from 2008 to 2011. Results Totally Acinetobacter baumannii 185 strains were mainly isolated from samples of sputum from 2008 to 2011, The constituent ratio of each year accounted for first place(25. 0%,18.2%,26. 7%,26.8%, respectively). Drugs resistant rate of Acinetobacter baumanii to commonly used drugs were over 50. 0%. Pandrug-resistant Acinetobacter baumannii strains were increased in 2010 - 2011 compared with 2008 - 2009(P<0. 05). Conclusion It was showed that Acinetobacter baumannii was high drugs resistance. Doctors should pay more attention to analyze the bacterial resistance profile in order to decrease the incidence of drug resistance.%目的 探讨ICU患者痰培养中鲍曼不动杆菌对常用抗菌药物耐药性变迁,为临床和医院感染管理提供第一手资料.方法 通过回顾性调查分析2008~2011年ICU 痰培养中鲍曼不动杆菌耐药性的变迁.结果 2008~2011 年ICU 痰培养分离鲍曼不动杆菌185株,每年的构成比均占首位(分别为25.0%、18.2%、26.7%、26.8%).鲍曼不动杆菌对常用药物的耐药率均超过50%;全耐药菌株检出率2010~2011年与2008~2009年比较呈明显上升趋势(P<0.05).结论 ICU 鲍曼不动杆菌耐药情况严重,应采取必要措施,减少细菌耐药的发生.

  5. Clinical analysis of 84 cases of acinetobacter baumannii infection in lower respiratory tract%下呼吸道感染鲍曼不动杆菌84例临床分析

    Institute of Scientific and Technical Information of China (English)

    杨素文; 姜琳; 李秋丰

    2014-01-01

    Objective To discusse and analyze the risk factor of acinetobacter baumannii infection in lower respiratory tract and drug resistance. Methods Choose 84 cases in our hospital from October 2010 to October 2013 to next breath behing acinetobacter baumannii infection treatment information on research and analysis of the lower respiratory tract infection study and analyze the drug resistance of acinetobacter baumannii. Results Gentamycin resistant rate was highest, the slime mold element B more resistance to a minimum. Conclusion In order to reduce the incidence rate of acinetobacter baumannii infection of lower respiratory tract, avoid to do a good job of hospital infection control, ensure the reasonable application of antibiotics.%目的:对下呼吸道感染鲍曼不动杆菌的易感因素和耐药性进行探讨和分析。方法选择84例于2010年10月~2013年10月间在本院进行下呼吸道道鲍曼不动杆菌感染治疗的患者资料进行研究和分析,对下呼吸道感染鲍曼不动杆菌的耐药性进行研究和分析。结果庆大霉素耐药率最高,多黏菌素B耐药率最低。结论为了降低下呼吸道感染鲍曼不动杆菌的发生率,避免做好医院感染控制工作,保证抗生素的合理应用。

  6. An amphipathic undecapeptide with all D-amino acids shows promising activity against colistin-resistant strains of Acinetobacter baumannii and a dual mode of action

    DEFF Research Database (Denmark)

    Oddo, Alberto; Thomsen, Thomas Thyge; Kjelstrup, Susanne;

    2016-01-01

    Multiple strains of Acinetobacter baumannii have developed multidrug resistance (MDR), leaving colistin as the only effective treatment. The cecropin-α-melittin hybrid BP100 (KKLFKKILKYL-NH2) and its analogs have previously shown activity against a wide array of plant and human pathogens. In this...... study, we investigated the in vitro antibacterial activities of 18 BP100 analogs (four known and 14 new) against the MDR A. baumannii strain ATCC BAA-1605, as well as against a number of other clinically relevant human pathogens. Selected peptides were further evaluated against strains of A. baumannii...... that acquired resistance to colistin due to mutations of the lpxC, lpxD, pmrA, and pmrB genes. The novel analogue BP214 showed antimicrobial activity at 1 to 2 μM and a hemolytic 50% effective concentration (EC50) of >150 μM. The lower activity of its enantiomer suggests a dual, specific and...

  7. 多重耐药鲍曼不动杆菌颅内感染一例报告及文献复习%Successful treatment of intracranial infection of multidrug - resistant Acinetobacter baumannii, case report and literature review

    Institute of Scientific and Technical Information of China (English)

    李达; 郝淑煜; 肖新如; 吴震; 张力伟; 张俊廷

    2010-01-01

    Objective To report one case of intracranial infection of multidrug - resistant Acinetobacter baumannii, and review the relative literature. Method The diagnosis was achieved by clinical features and bacterial culture of cerebral spinal fluid. Results The patient was diagnosis as intracranial infection of Acinetobacter baumannii. It was successfully treated with intravenous and intrathecal colistin. Conclutions Combination of intravenous and intrathecal colistin is an effective and safe therapy for the treatment of Acinetobacter baumannii intracranial infection.%目的 介绍1例术后颅内多重耐药鲍曼不动杆菌感染病例成功治疗经验并文献复习.方法 通过临床表现和脑脊液细菌培养确诊为多重耐药鲍曼不动杆菌感染.结果 联合鞘内和静脉注射多黏菌素,患者痊愈.结论 多黏菌素治疗颅内多重耐药鲍曼不动杆菌感染可取得良好预后.

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

    Science.gov (United States)

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

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Analysethe antimicrobial resistance of 1067 strains of acinetobacter baumannii%1067株鲍曼不动杆菌耐药性分析

    Institute of Scientific and Technical Information of China (English)

    饶友义; 余江平

    2012-01-01

    Objective To offer reliable evidence to control and treat the infection of baumanii, we have analyzed the antimicrobial resistance of baumanii strains form patients in our hospital. Methods According to the national clinical inspection operation specifications to separation bacteria and bacterial cultures. Use VITEK of france's biological merry company to strains identified and drug susceptibility test with it' s pillbox. The results standard judgement according to the CLSI. Use the WHONT5. 4 software to analyzes the data. Results The acinetobacter baumannii in our hospital mainly distribute in ICU and department of respiratory medicine, Drug Resistance Rate is higher, amikacin has minimum resistance is 34. 4% , The rest of the resistance are more than 50%. Conclusion Acinetobacter baumannii has higher drug resistance rate, which should be more high attention to clinical doctors.%目的 分析本院临床分离鲍曼不动杆菌的耐药性,为临床提供控制和治疗该菌感染的可靠依据.方法 细菌培养分离按照《全国临床检验操作规程》进行.采用法国生物梅里埃公司全自动微生物鉴定系统进行菌种鉴定及配套药盒做药敏,药敏试验结果按照CLSI标准判定,采用WHONT5.4软件进行数据分析.结果 分离的鲍曼不动杆菌主要分布在ICU、呼吸科感染患者,有较高耐药率,阿米卡星耐药率最低为34.4%,其余的耐药率均在50%以上.结论 鲍曼不动杆菌耐药率较高,应引起临床高度重视.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Two Multiplex Real-Time PCR Assays to Detect and Differentiate Acinetobacter baumannii and Non- baumannii Acinetobacter spp. Carrying blaNDM, blaOXA-23-Like, blaOXA-40-Like, blaOXA-51-Like, and blaOXA-58-Like Genes.

    Science.gov (United States)

    Yang, Qiu; Rui, Yongyu

    2016-01-01

    Nosocomial infections caused by Acinetobacter spp. resistant to carbapenems are increasingly reported worldwide. Carbapenem-resistant Acinetobacter (CRA) is becoming a serious concern with increasing patient morbidity, mortality, and lengths of hospital stay. Therefore, the rapid detection of CRA is essential for epidemiological surveillance. Polymerase chain reaction (PCR) has been extensively used for the rapid identification of most pathogens. In this study, we have developed two multiplex real-time PCR assays to detect and differentiate A. baumannii and non-A. baumannii Acinetobacter spp, and common carbapenemase genes, including blaNDM, blaOXA-23-like, blaOXA-40-like, blaOXA-51-like, and blaOXA-58-like. We demonstrate the potential utility of these assays for the direct detection of blaNDM-, blaOXA-23-like-, blaOXA-40-like-, blaOXA-51-like-, and blaOXA-58-like-positive CRA in clinical specimens. Primers were specifically designed, and two multiplex real-time PCR assays were developed: multiplex real-time PCR assay1 for the detection of Acinetobacter baumannii 16S-23S rRNA internal transcribed spacer sequence, the Acinetobacter recA gene, and class-B-metalloenzyme-encoding gene blaNDM; and multiplex real-time PCR assay2 to detect class-D-oxacillinase-encoding genes (blaOXA-23-like, blaOXA-40-like, blaOXA-51-like,and blaOXA-58-like). The assays were performed on an ABI Prism 7500 FAST Real-Time PCR System. CRA isolates were used to compare the assays with conventional PCR and sequencing. Known amounts of CRA cells were added to sputum and fecal specimens and used to test the multiplex real-time PCR assays. The results for target and nontarget amplification showed that the multiplex real-time PCR assays were specific, the limit of detection for each target was 10 copies per 20 μL reaction volume, the assays were linear over six log dilutions of the target genes (r2 > 0.99), and the Ct values of the coefficients of variation for intra- and interassay

  13. Two Multiplex Real-Time PCR Assays to Detect and Differentiate Acinetobacter baumannii and Non- baumannii Acinetobacter spp. Carrying blaNDM, blaOXA-23-Like, blaOXA-40-Like, blaOXA-51-Like, and blaOXA-58-Like Genes.

    Directory of Open Access Journals (Sweden)

    Qiu Yang

    Full Text Available Nosocomial infections caused by Acinetobacter spp. resistant to carbapenems are increasingly reported worldwide. Carbapenem-resistant Acinetobacter (CRA is becoming a serious concern with increasing patient morbidity, mortality, and lengths of hospital stay. Therefore, the rapid detection of CRA is essential for epidemiological surveillance. Polymerase chain reaction (PCR has been extensively used for the rapid identification of most pathogens. In this study, we have developed two multiplex real-time PCR assays to detect and differentiate A. baumannii and non-A. baumannii Acinetobacter spp, and common carbapenemase genes, including blaNDM, blaOXA-23-like, blaOXA-40-like, blaOXA-51-like, and blaOXA-58-like. We demonstrate the potential utility of these assays for the direct detection of blaNDM-, blaOXA-23-like-, blaOXA-40-like-, blaOXA-51-like-, and blaOXA-58-like-positive CRA in clinical specimens. Primers were specifically designed, and two multiplex real-time PCR assays were developed: multiplex real-time PCR assay1 for the detection of Acinetobacter baumannii 16S-23S rRNA internal transcribed spacer sequence, the Acinetobacter recA gene, and class-B-metalloenzyme-encoding gene blaNDM; and multiplex real-time PCR assay2 to detect class-D-oxacillinase-encoding genes (blaOXA-23-like, blaOXA-40-like, blaOXA-51-like,and blaOXA-58-like. The assays were performed on an ABI Prism 7500 FAST Real-Time PCR System. CRA isolates were used to compare the assays with conventional PCR and sequencing. Known amounts of CRA cells were added to sputum and fecal specimens and used to test the multiplex real-time PCR assays. The results for target and nontarget amplification showed that the multiplex real-time PCR assays were specific, the limit of detection for each target was 10 copies per 20 μL reaction volume, the assays were linear over six log dilutions of the target genes (r2 > 0.99, and the Ct values of the coefficients of variation for intra- and

  14. 耐碳青霉烯类鲍氏不动杆菌的同源性分析%Homogeneity of carbapenem-resistant acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    陈海红; 李华茵; 何礼贤; 胡必杰; 陈雪华; 周春妹; 高晓东

    2011-01-01

    OBJECTIVE To investigate the homogeneity and molecular epidemiology of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates selected from different wards of the Zhongshan Hospital. METHODS The identification and antimicrobial susceptibility test of A. baumannii were done according to the standardized protocol The pulse-field gel electrophoresis (PFGE) was used to type the resistance isolates gathered in our hospital, determining whether they derived from the same clone or not. RESULTS A total of 63 strains of CRAB were recovered from patients admission between 2007 and 2008 in our hospital. A total of 11 distinct genotypic patterns were identified using PFGE(A,C-M). In the last two years, PFGE types C and E were the dominate clone including 20 and 20 clonally related strains, respectively. Clone C dominated in SICU, while clone G1 in EICU, clone E in respiratory ward and emergency observation room. During February to June in 2005, 2 different PFGE genotypes were detected in 5 strains of CRAB(A and B) from SICU, of which clone B accounted for 80.0%. None of the clone B appeared in 2007 and 2008. PFGE type A was first isolated from a patient in the respiratory ward in February 2005, and other strains in this clone were isolated from the respiratory wards and other wards of the hospital during the following years (until December 2008). CONCLUSIONS This is the first homogeneity description of CRAB infection in hospital. PFGE types C and E are the predominant clone in hospital in the last two years and clone G1 and clone E cause the spread of CRAB infection. There's one respective clone dominated in each ward, which suggests that the increasing rate of CRAB infections is corresponded to the spread of the close clonally related strains. In contrast to carbapenem-resistant strains collected in 2005, PFGE types have changed in 2007 and 2008. Clonally related strains can survive for a long time in hospital and cause nosocomial infections at various times in

  15. Study on in vitro antimicrobial activity of Colistin and other antibiotics against Acinetobacter baumannii%粘菌素等抗菌药物对临床分离鲍曼不动杆菌的抗菌活性

    Institute of Scientific and Technical Information of China (English)

    李然; 史录文; 王睿; 梁蓓蓓; 宋秀杰; 蔡芸

    2009-01-01

    AIM: To investigate the antimicrobial activity of Colistin and other antibiotics against Acine-tobacter baumannii. METHODS: The agar dilution method was used to determine the minimum inhibitory concentrations (MICs) of Colistin and other antibiotics against 70 Acinetobacter baumannii collected from PLA General Hospital, Peking Hospital and Beijing Union Hospital. The sensitive rate was judged by CLSI stan- dard. RESULTS: The resistant rates of 70 Acineto-bacter baumannii to penicillins and cephalosporins, carbopenems ( meropenem and imipenem/eilastatin ), aminoglycosides(netilmicin and amikacin) , fluoroquin-olones(ciprofloxacin and levofloxacin) were 71.4% -82.9%, 75.7% - 77.1%, 71.4% - 75.7%, 32.8% - 82.9% . Fifty-five multidrug-resistant Acin-etobacter baumannii were isolated. All Acinetobacter baumannii in the study were sensitive to Colistin, the MIC_(50) and MIG_(90) were both 1 μg/mL. CONCLU- SION : Acinetobacter baumannii in the study were resistant to many antibiotics including penicillins and cephalosporins, carbopenems, aminoglycosides. Colistin has good antimicrobial activity against Aeinetobacter baumannii.%目的:评价粘菌素对临床分离多药耐药鲍曼不动杆菌的抗菌活性.方法:收集解放军总医院、北京医院、北京协和医院3家医院分离的非重复分离鲍曼不动杆菌70株,采用琼脂稀释法测定粘菌素与其他12种抗菌药物的最低抑菌浓度(MIC),以CLSI标准判断其敏感率.结果:70株鲍曼不动杆菌,对青霉素类和头孢菌素类的耐药率为71.4%~82.9%,对碳青霉烯类(美罗培南、亚胺培南/西司他丁)的耐药率为75.7%~77.1%,对氨基糖苷类(奈替米星、阿米卡星)的耐药率为71.4%~75.7%,对氟喹酮类的耐药率(环丙沙星、左氧氟沙星)为32.9%~82.9%.共筛选出多药耐药鲍曼不动杆菌55株,对粘菌素全部敏感,MIC_(50)和MIC_(90)均为1/μg/mL.结论:鲍曼不动杆菌对本研究的大多数抗菌药物耐药率较高,粘菌素

  16. 1685株鲍曼不动杆菌的临床分布及耐药性研究%Clinical distribution and antibiotics resistance of 1 685 strains of Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    邓健康; 郭晓兰

    2016-01-01

    目的:探讨川北医学院附属医院鲍曼不动杆菌感染的临床分布和耐药特点,为该菌的感染治疗与预防提供依据。方法该院2011~2014年住院患者送检标本中分离的1685株鲍曼不动杆菌的分布及耐药性检测。结果鲍曼不动杆菌主要分离自痰液标本,占73.1%;以重症监护病房和神经外科病房检出率最高;该菌仅对头孢哌酮/舒巴坦和米诺环素耐药率低,分别为27.9%和26.9%;对亚胺培南、美罗培南的耐药率分别为77.4%、73.9%;对其余多种抗菌药物耐药率在62.0%以上。结论鲍曼不动杆菌的耐药率较高并具有多重耐药性,临床治疗应及时进行细菌耐药性监测并根据药敏试验结果选择合适的抗菌药物。%Objective To investigate the clinical distribution and antibiotics resistance of Acinetobacter bau‐mannii in Affiliated Hospital of North Sichuan Medical College and in order to provide evidence for clinical treatment and prevention of Acinetobacter baumannii infection .Methods A retrospective statistical analysis was performed on the clinical distribution and antibiotics resistance results of 1 685 Acinetobacter baumannii isolates from inpatient be‐tween 2011 and 2014 .Results Most of the Acinetobacter baumannii isolates were isolated from sputum specimens (73 .1% ) .Patients who infected by Acinetobacter baumannii were found mainly from the intensive care unit ward and neurosurgery department .More than 62 .0% of Acinetobacter baumannii isolates were resistant to all the the antibac‐terial agents tested except cefoperazone‐sulbactam (the resistance rate was 27 .9% ) and minocycline(the resistance rate was 26 .9% ) ,About 74 .0% and 73 .1% of these strains were resistant to imipenem and meropenem ,respective‐ly .Conclusion The Acinetobacter baumanii strains had seriously resistant and multidrud‐resistant to many kinds of antibiotics except of cefoperazone

  17. Analysis on drug-resistance and molecular epidemiology of Acinetobacter baumannii isolated from the clinical samples in two Chinese hospitals

    Institute of Scientific and Technical Information of China (English)

    WEI FENG SHI; ZHI MI HUANG; NING XU

    2006-01-01

    In the present study, the drug-resistance genes encoding β-lactamases, aminoglycoside modifying enzymes, DNA topoisomerases and integron as well as their molecular epidemiology were investigated by means of analyzing the drug-resistance and molecular epidemiology of Acinebacter baumannii isolated from the clinical samples in two hospitals in Changzhou and Huzhou city of Jiangsu and Zhejiang province from July 2000 to March 2005. The minimal inhibitory concentrations (MICs) of these 307 isolates were detected by automatic microbiological system, and 35 strains against 5-fluoroquinolones were performed by agar dilution assay. Meanwhile, the resistant genes in 80 isolates were amplified by PCR with identification by DNA sequencer. It was found that most of the 307 isolates of A. baumannii were resistant to multiple antibiotics tested, in which the resistance rates of the isolates against piperacillin, piperacillin/tazobactam, amoxacillin/clavulanic acid, cefotaxime, ceftazidime,cefepime, gentamicin, amikacin, ciprofloxacin, chloramphenicol and sulfamethoxazole/trimethoprim were all above 35%, but those of imipenem and meropenem were quite low, ranged only 2.6% and 3.3 %. In addition, it was also demonstrated that the positive rates of TEM and SHV β-lactamase genes accounted for 93.8% and 22.5% respectively, and those of the aminoglycoside-modifying enzyme genes including aacC1, aacC2, aacC3, aacC4, aacC4A, aphA6, ant(2")-Ⅰ and ant(3")-Ⅰ were 58.8%, 8.8%, 7.5%, 28.8%, 45.0%, 2.5%, 28.8% and 65.0% respectively. The mutations in the quinolone-resistant determining region (QRDR) of gyrA and parC genes indicated that substitution in Ser-83 residue of GyrA protein was most frequently occurred among strains with MIC for ciprofloxacin of more than 4 μg/ml, whereas a double mutation at Ser-83 residue of gyrA and Ser-80 of parC was found in strains with MIC of ciprofloxacin of more than 8 μg/ml. As to the positive rates of class 1 integron (Int Ⅰ -1) and qacE△1-sul

  18. 医院内鲍曼不动杆菌感染调查及泛耐药情况分析%Analysis on the infection and extensive drug-resistance of Acinetobacter baumannii in hospital

    Institute of Scientific and Technical Information of China (English)

    王箭; 罗君; 王丽娟

    2011-01-01

    目的:了解某院近3年来医院内鲍曼不动杆菌感染现状,分析其耐药谱变迁及泛耐药情况,为临床了解及防控院内感染提供依据.方法:对医院2007年-2009年分离的鲍曼不动杆菌分布及耐药情况进行回顾性分析.细菌鉴定采用美国德灵细菌鉴定仪.结果:3年间共分离到鲍曼不动杆菌305株,其中2007年72株,2008年91株,2009年142株,其中通过呼吸道感染占82.12%.泛耐药菌株感染率呈现出逐年上升趋势,2007年5株(占6.94%),2008年9株(占9.89%),2009年有19株(占13.38%).结论:鲍曼不动杆菌感染呈逐年上升趋势,以呼吸道感染方式为主,其泛耐药菌株感染率呈上升趋势.应加强病房环境和人员消毒,加强抗生素的合理使用,控制鲍曼不动杆菌在医院内的定值和播散,重视泛耐药鲍曼不动杆菌监测.%Objective: To study the infection situation of Acinetobacter baumannii in Yuebei hospital in the past three years,analyze the transition and status of extensive drug - resistance, provide the evidence for clinical study and the prevention of hospital infection. Methods: A retrospective analysis for the distribution and drug - resistance of Acinetobacter baumannii from 2007 -2009. Bacteria were identified by identification instrument from America. Results: 305 Acinetobacter baumannii were isolated in the past three years, among which 72 strains from 2007, 91strains from 2008, 142 strains from 2009, and totally 82.12% were infected by respiratory tract. The infection rate of pandrug - resistance strain rose year by year, among which 5 strains in 2007 (6.94%), 9 strains in 2008 (9.89%), 19 strains in 2009 ( 13.38% ). Conclusion: It showed a rising trend of the infection of Acinetobacter baumannii, the main infection way was respiratory tract and the infection rate of pandrug - resistance strain rose year by year. As such, it is suggested to strengthen the ward and personal decontamination, use the antibiotics properly

  19. Acinetobacter baumannii biofilm and antimicrobial resistance correlation Analysis%鲍曼不动杆菌生物被膜与耐药性的相关性分析

    Institute of Scientific and Technical Information of China (English)

    赖其伟; 黄丽芳

    2016-01-01

    Objective To investigate the correlation between Acinetobacter baumannii biofilms and their drug resistance .Meth‐ods The clinical distribution ,biofilm formation and the correlation between biofilm formation and drug resistance of Acinetobacter baumannii isolated in the hospital from June 2011 to August 2014 were studied .Results The types of specimens from which the Acinetobacter baumannii stains were isolated were mainly sputum ,secretion and peritoneal effusion .There were 56 strains with"+"biofilm intensity accounting for 66 .67% (56/84) ,and 3 strains with"-"biofilm intensity accounting for 3 .57% (3/84) which was relatively lower .96 .43% of the Acinetobacter baumannii had strong ability of biofilm formation .The strains with the ability to form biofilm had stonger drug resistance than those without the ability(P0 .05) .Conclusion Acinetobacter baumannii biofilms and their drug resistance are closely related ,but biofilms intensity are not correlated with the drug resistance .Therefore ,further study needs to be done on the relationship between biofilms of Acinetobacter baumannii and the drug resistance .%目的:探讨鲍曼不动杆菌生物被膜与其耐药性的相关性。方法对2011年6月至2014年8月该院分离的鲍曼不动杆菌临床分布、生物膜形成情况及生物膜形成与耐药性的关系进行研究。结果标本来源主要为痰液、分泌物、腹腔积液等;强度为“+”生物膜菌株56株,占66.67%(56/84);强度为“-”生物膜菌株3株,占3.57%(3/84),所占比例最低,96.43%鲍曼不动杆菌具有较强的生物膜形成能力;具有生物膜的菌株耐药性明显高于不具有生物膜的菌株,差异有统计学意义(P<0.05),不同强度生物膜菌株的耐药性比较差异无统计学意义(P>0.05)。结论鲍曼不动杆菌生物膜与其耐药性密切相关,但不同强度生物膜与其耐药性无明显相关性,值得对生

  20. Changes of drug resistance of Acinetobacter baumannii isolated from our hospital in recent three years%某院近3年鲍曼不动杆菌耐药性变迁

    Institute of Scientific and Technical Information of China (English)

    马明炎; 廖利雅; 熊中政

    2013-01-01

    目的分析垫江县人民医院2010~2012年鲍曼不动杆菌的耐药性变迁,为临床合理用药并有效控制鲍曼不动杆菌感染提供依据。方法针对该院2010~2012年临床分离的鲍曼不动杆菌耐药情况及患者的感染情况进行回顾性统计分析。结果鲍曼不动杆菌的临床分离率从2010年的218例(12.19%)增高到2012年的741例(18.48%)。18种抗菌药物耐药率基本都在70%以上,重症监护病房、神经科等科室出现泛耐药菌株。抗菌药物的选择性压力是细菌发生耐药性变迁的主要动因之一,年龄、基础疾病、住院时间及侵入性操作等是患者感染的高危因素。结论医院应加强医疗环境、医疗器械及医护人员的消毒,加强医院感染监测,合理使用抗菌药物等一系列措施,可有效控制鲍曼不动杆菌的感染。%Objective To analyze the changes of drug resistance of Acinetobacter baumannii in our hospital during 2010-2012 to provide reference for clinical rational drug use and the effective control of Acinetobacter baumannii infection .Methods The drug resistance of Acinetobacter baumannii clinically isolated from 2010 to 2012 and its infection situation were retrospectively performed the statistical analysis .Results The clinical isolation rate of Acinetobacter baumannii in our hospital was increased from 218 cases (12 .19% ) to 741 cases (18 .48% ) in 2012 .The resistance rates of 18 kinds of antibiotics were almost more than 70% ,and pan-drug-resistant Acinetobacter baumannii appeared in some clinical departments ,such as ICU and neurology .The selective pressure of antibiotic was one of the main motive causes of drug resistance change ,and age ,underlying diseases ,duration of hospitalization and invasive procedures were the high risk factors in patients infection .Conclusion Hospital should enhance a series of measures including reinforcing the disinfection of the medical environment

  1. Analysis of risk factors and drug resistance of Acinetobacter baumannii infection%鲍曼不动杆菌感染的危险因素及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    汪志方; 张益辉; 王泽球

    2012-01-01

    目的 了解我院鲍曼不动杆菌的感染危险因素及耐药性.方法 经采用常规方法进行细菌培养、菌株鉴定及药敏检测.结果 158例患者共分离出238株鲍曼不动杆菌,患者主要集中在老年科(27.8%)、呼吸内科(26.6%)、神经内科(24.1%)、ICU( 16.5%),基础疾病以肺部疾病(77.8%)、神经系统疾病(51.9%)、心血管疾病(43.0%)、糖尿病(32.9%)多见,与有创检查或治疗(64.6%)、使用广谱抗生素(86.1%)可能存在相关性.对头孢哌酮/舒巴坦敏感性(66.4%)较高.对碳青霉烯类抗生素耐药性逐年上升,由20.4%上升至40.2%.结论鲍曼不动杆菌耐药情况严重,对碳青霉烯类耐药率逐年上升,可能与患者基础疾病、有创性检查或治疗、使用广谱抗生素有关.%Objective To investigate the risk factors of infection of Acinetobacter baumannii, and to analyze drug resistance of Acinetobacter baumannii strains. Methods The isolation of the bacterium was conducted according to the microorganical method of CLSI (Clinical and Laboratory Standards Institute). France BioMerieux ATB automatic analyzer was applied to species identification and drug susceptibility test. Drug resistance was calculated with WH0NET5.4, and the results were analyzed with SPSS software. Results A total of 238 strains of Acinetobacter baumannii were isolated from 158 patients. The patients were mainly from geriatric department (27. 8% ) , department of respiratory medicine (26. 6% ) , department of neurology (24. 1% ) , and intensive care unit (16. 5% ). Common underlying diseases were pulmonary diseases (77. 8% ), diseases of nervous system(52. 9% ) , cardiovascular diseases(43. 0% ) and diabetes (32. 9% ). 64. 6% of the patients had accepted invasive operations before infection, and 86. 1% were infused with broad-spectrum antibiotics, which indicated invasive operations and broad-spectrum antibiotics may be risk factors of infection of Acinetobacter

  2. 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

  3. IncM Plasmid R1215 Is the Source of Chromosomally Located Regions Containing Multiple Antibiotic Resistance Genes in the Globally Disseminated Acinetobacter baumannii GC1 and GC2 Clones

    OpenAIRE

    Blackwell, Grace A.; Hamidian, Mohammad; Hall, Ruth M.

    2016-01-01

    ABSTRACT Clear similarities between antibiotic resistance islands in the chromosomes of extensively antibiotic-resistant isolates from the two dominant, globally distributed Acinetobacter baumannii clones, GC1 and GC2, suggest a common origin. A close relative of the likely progenitor of both of these regions was found in R1215, a conjugative IncM plasmid from a Serratia marcescens strain isolated prior to 1980. The 37.8-kb resistance region in R1215 lies within the mucB gene and includes aac...

  4. Epidemiological study of Acinetobacter baumannii infections and countermeasures%鲍氏不动杆菌医院感染流行病学调查及对策

    Institute of Scientific and Technical Information of China (English)

    胡美春; 杨西宁; 韦柳青; 宋英娇

    2013-01-01

    OBJECTIVE To investigate the prevalence of Acinetobacter baumannii infections in the hospital so as to put forward the control measures to reduce the incidence of nosocomial infections. METHODS By means of retrospective survey, the clinical data of 122 patients who suffered from the nosocomial infections from Jan to Dec were statistically analyzed. RESULTS The incidence rate and case-time rate of Acinetobacter infections were 0. 34% and 0. 41% , respectively ; the average age of the patients with infections was 60. 20 years old, the average hospitalization duration was 39. 17 days. Of 122 patients invested, the majority was comp; izated with such severe primary diseases as cardiovascular and cerebrovascular diseases, tumor, and severe craniocerebral injury. The Acinetobacter baumannii infections mainly occurred in ICU (29. 15%) and neurosurgery department ( 12. 30% ); Within the 6 involved infected sites, the lower respiratory tract has the highest incidence rate (74. 29% ), and the subsequent sites were burn wound and upper respiratory tract. The isolated strains of Acinetobacter were mainly from sputum specimcns. Totally 36 cases were with mixed infections, among which there were 30 cases with the infections caused by two species and 6 cases with the infections caused by 3 species. Of 122 cases of patients with infections, there were 35 cases cured, 70 cases improved, 18 cases without being cured, and 17 cases having died ,with the mortality of 13. 94%. CONCLUSION The Acinetobacter infections mainly occur in the senile patients with severe underlying diseases and long hospital stay and mainly distribute in the ICU and the neurosurgery department. The respiratory tract and the incision are dominant in the infection sites . The mixed infections are very common. The mortality is high.%目的 了解医院鲍氏不动杆菌医院感染流行现状,提出控制措施降低医院感染率.方法 采用回顾性调查的方法,对2010年1月-12月发生医院感染的122

  5. Quinolone-resistant phonotype and genetic mechanisms of 120 strains of Acinetobacter baumannii%120株临床分离鲍曼不动杆菌对喹诺酮类耐药表型及其机制

    Institute of Scientific and Technical Information of China (English)

    袁星; 沈继录; 徐元宏; 熊自忠

    2011-01-01

    目的 了解鲍曼不动杆菌对喹诺酮类抗菌药物的常见耐药性及其机制,为临床抗感染治疗提供依据,以指导临床合理用药.方法 采用VITEK系统鉴定细菌,用M-H琼脂定量稀释法测定菌株对左氧氟沙星、环丙沙星和加替沙星3种喹诺酮类药物的最低抑菌(MIC),PCR扩增gyrA和parC基因,选取部分PCR扩增产物进行测序分析.结果 临床标本共检出120株鲍曼不动杆菌,中心重症监护室、呼吸科病房、急救中心分离菌所占比率分别为28.3%、24.2%、12.5%;对环丙沙星、左氧氟沙星和加替沙星的耐药率分别为78.3%、58.3%和40.0%.PCR基因扩增和测序结果:所有菌株均扩增出了相应gyrA和parC基因产物;耐药株中的gyrA基因存在83位氨基酸密码子突变,敏感株中则不存在该突变,并在耐药株中发现gyrA和parC基因针对GenBank号分别为DQ270238和EU977576的菌株存在新的点突变.结论 鲍曼不动杆菌对喹诺酮类药物耐药情况严重,其耐药性与gyrA和parC基因点突变有关.%Objective To investigate the distribution and drug resistance of Acinetobacter baumanii strains isolated in our hospital, to examine the genetic mechanisms of resistance by molecular methods and to provide evidence for the clinical therapy of infections. Methods Microorganisms were identified by VITEK system, minimum inhibitory concentration(MICs) of levofloxaein, ciprofloxacin and gatifloxacin were determined by using agar dilution method.Genes gyrA and parC were amplified by polymerase chain reaction (PCR), and some PCR products were sequenced. Results A total of 120 strains of Acinetobacter baumanii species were collected, the percentage of isolated bacteria in intensive care unit, respiratory department and emergency center was 28.3% ,24. 2%, 12. 5% respectively. The resistance rate of Acinetobacter baumanii isolates to ciprofloxacin, levofloxacin and gatifloxacin was 78.3% ,58.3% and 40. 0% respectively. PCR and

  6. Drug-resistance Acinetobacter baumannii infection in burn patients: current situation and countermeasure%烧伤患者耐药鲍氏不动杆菌感染现状和对策

    Institute of Scientific and Technical Information of China (English)

    郇京宁; 唐佳俊

    2011-01-01

    @@ 不动杆菌自1911年被发现以来,已确定至少有32个不同种类,其中大部分不致病,广泛分布于自然环境中,并可寄生于健康人体.鲍氏不动杆菌属于莫拉菌科的革兰阴性非发酵杆菌,感染范围包括呼吸道、血液、皮肤和软组织以及各类植入性医疗器材等.在过去10年内,鲍氏不动杆菌表现出多药耐药或泛耐药性,已成为ICU、烧伤病房细菌感染的重要病原菌,是全球面临的临床棘手问题.为此,笔者结合本团队基础研究和临床工作经验,分析和评述鲍氏不动杆菌耐药机制及防治其感染的对策.%Infections caused by Acinetobacter baumannii (AB) have emerged as a knotty clinical problem in the burn wards due to its omni-resistance to antibiotics and high prevalence. Although our knowledge in regard to the pathogenesis and the resistance mechanisms of AB is increasing, the available treatment remains much limited. Measures to effectively control nosocomial infection are warranted. Meanwhile, development of novel therapeutic agents or combination of antibiotics should be considered.

  7. Chromosomal integration of a cephalosporinase gene from Acinetobacter baumannii into Oligella urethralis as a source of acquired resistance to beta-lactams.

    Science.gov (United States)

    Mammeri, Hedi; Poirel, Laurent; Mangeney, Nicole; Nordmann, Patrice

    2003-05-01

    Clinical Oligella urethralis isolate COH-1, which was uncommonly resistant to penicillins and narrow-spectrum cephalosporins, was recovered from a 55-year-old patient with a urinary tract infection. Shotgun cloning into Escherichia coli and expression experiments gave recombinant clones expressing either an AmpC beta-lactamase-type phenotype of resistance or a carbenicillin-hydrolyzing beta-lactamase-type phenotype of resistance. The AmpC beta-lactamase identified (ABA-1), which had a pI value of 8.2, had 98% amino acid identity with a chromosomally encoded cephalosporinase of Acinetobacter baumannii. A 820-bp insertion sequence element, ISOur1, belonging to the IS6 family of insertion sequence elements, was identified immediately upstream of bla(ABA-1), providing a -35 promoter sequence and likely giving rise to a hybrid promoter region. The carbenicillin-hydrolyzing beta-lactamase identified (CARB-8), which had a pI value of 6.4, differed from CARB-5 by two amino acid substitutions. Hybridization of CeuI fragment I-restricted DNA fragments of O. urethralis COH-1 with bla(ABA-1)-, bla(CARB-8)-, and 16S rRNA-specific probes indicated the chromosomal integration of the beta-lactamase genes. PCR and hybridization experiments failed to detect bla(CARB-8)- and bla(ABA-1)-like genes in three O. urethralis reference strains, indicating that the beta-lactamase genes identified were the source of acquired resistance in O. urethralis COH-1. This is one of the few examples of the interspecies transfer and the chromosomal integration of a gene encoding a naturally occurring beta-lactamase.

  8. Activity of Colistin in Combination with Meropenem, Tigecycline, Fosfomycin, Fusidic Acid, Rifampin or Sulbactam against Extensively Drug-Resistant Acinetobacter baumannii in a Murine Thigh-Infection Model.

    Directory of Open Access Journals (Sweden)

    Bing Fan

    Full Text Available Few effective therapeutic options are available for treating severe infections caused by extensively drug-resistant Acinetobacter baumannii (XDR-AB. Using a murine thigh-infection model, we examined the in vivo efficacy of colistin in combination with meropenem, tigecycline, fosfomycin, fusidic acid, rifampin, or sulbactam against 12 XDR-AB strains. Colistin, tigecycline, rifampin, and sulbactam monotherapy significantly decreased bacterial counts in murine thigh infections compared with those observed in control mice receiving no treatment. Colistin was the most effective agent tested, displaying bactericidal activity against 91.7% of strains at 48 h post-treatment. With strains showing a relatively low minimum inhibitory concentration (MIC for meropenem (MIC ≤ 32 mg/L, combination therapy with colistin plus meropenem caused synergistic inhibition at both 24 h and 48 h post-treatment. However, when the meropenem MIC was ≥64 mg/L, meropenem did not significantly alter the efficacy of colistin. The addition of rifampin and fusidic acid significantly improved the efficacy of colistin, showing a synergistic effect in 100% and 58.3% of strains after 24 h of treatment, respectively, while the addition of tigecycline, fosfomycin, or sulbactam did not show obvious synergistic activity. No clear differences in activities were observed between colistin-rifampin and colistin-fusidic acid combination therapy with most strains. Overall, our in vivo study showed that administering colistin in combination with rifampin or fusidic acid is more efficacious in treating XDR-AB infections than other combinations. The colistin-meropenem combination may be another appropriate option if the MIC is ≤32 mg/L. Further clinical studies are urgently needed to confirm the relevance of these findings.

  9. Activity of Colistin in Combination with Meropenem, Tigecycline, Fosfomycin, Fusidic Acid, Rifampin or Sulbactam against Extensively Drug-Resistant Acinetobacter baumannii in a Murine Thigh-Infection Model

    Science.gov (United States)

    Wang, Xiumei; Cong, Yulong

    2016-01-01

    Few effective therapeutic options are available for treating severe infections caused by extensively drug-resistant Acinetobacter baumannii (XDR-AB). Using a murine thigh-infection model, we examined the in vivo efficacy of colistin in combination with meropenem, tigecycline, fosfomycin, fusidic acid, rifampin, or sulbactam against 12 XDR-AB strains. Colistin, tigecycline, rifampin, and sulbactam monotherapy significantly decreased bacterial counts in murine thigh infections compared with those observed in control mice receiving no treatment. Colistin was the most effective agent tested, displaying bactericidal activity against 91.7% of strains at 48 h post-treatment. With strains showing a relatively low minimum inhibitory concentration (MIC) for meropenem (MIC ≤ 32 mg/L), combination therapy with colistin plus meropenem caused synergistic inhibition at both 24 h and 48 h post-treatment. However, when the meropenem MIC was ≥64 mg/L, meropenem did not significantly alter the efficacy of colistin. The addition of rifampin and fusidic acid significantly improved the efficacy of colistin, showing a synergistic effect in 100% and 58.3% of strains after 24 h of treatment, respectively, while the addition of tigecycline, fosfomycin, or sulbactam did not show obvious synergistic activity. No clear differences in activities were observed between colistin-rifampin and colistin-fusidic acid combination therapy with most strains. Overall, our in vivo study showed that administering colistin in combination with rifampin or fusidic acid is more efficacious in treating XDR-AB infections than other combinations. The colistin-meropenem combination may be another appropriate option if the MIC is ≤32 mg/L. Further clinical studies are urgently needed to confirm the relevance of these findings. PMID:27315107

  10. Clinical Specimen-Direct LAMP: A Useful Tool for the Surveillance of blaOXA-23-Positive Carbapenem-Resistant Acinetobacter baumannii.

    Science.gov (United States)

    Yamamoto, Norihisa; Hamaguchi, Shigeto; Akeda, Yukihiro; Santanirand, Pitak; Kerdsin, Anusak; Seki, Masafumi; Ishii, Yoshikazu; Paveenkittiporn, Wantana; Bonomo, Robert A; Oishi, Kazunori; Malathum, Kumthorn; Tomono, Kazunori

    2015-01-01

    Healthcare-associated infections are a leading cause of morbidity and mortality worldwide. Treatment is increasingly complicated by the escalating incidence of antimicrobial resistance. Among drug-resistant pathogens, carbapenem-resistant Acinetobacter baumannii (CRAb) is of increasing concern because of the limited applicable therapies and its expanding global distribution in developed countries and newly industrialized countries. Therefore, a rapid detection method that can be used even in resource-poor countries is urgently required to control this global public health threat. Conventional techniques, such as bacterial culture and polymerase chain reaction (PCR), are insufficient to combat this threat because they are time-consuming and laborious. In this study, we developed a loop-mediated isothermal amplification (LAMP) method for detecting blaOXA-23-positive CRAb, the most prevalent form of CRAb in Asia, especially in Thailand, and confirmed its efficacy as a surveillance tool in a clinical setting. Clinical samples of sputum and rectal swabs were collected from patients in a hospital in Bangkok and used for LAMP assays. After boiling and centrifugation, the supernatants were used directly in the assay. In parallel, a culture method was used for comparison purposes to evaluate the specificity and sensitivity of LAMP. As a first step, a total of 120 sputum samples were collected. The sensitivity of LAMP was 88.6% (39/44), and its specificity was 92.1% (70/76) using the culture method as the "gold standard". When surveillance samples including sputum and rectal swabs were analyzed with the LAMP assay, its sensitivity was 100.0%. This method enables the direct analysis of clinical specimens and provides results within 40 minutes of sample collection, making it a useful tool for surveillance even in resource-poor countries.

  11. Clinical Specimen-Direct LAMP: A Useful Tool for the Surveillance of blaOXA-23-Positive Carbapenem-Resistant Acinetobacter baumannii.

    Directory of Open Access Journals (Sweden)

    Norihisa Yamamoto

    Full Text Available Healthcare-associated infections are a leading cause of morbidity and mortality worldwide. Treatment is increasingly complicated by the escalating incidence of antimicrobial resistance. Among drug-resistant pathogens, carbapenem-resistant Acinetobacter baumannii (CRAb is of increasing concern because of the limited applicable therapies and its expanding global distribution in developed countries and newly industrialized countries. Therefore, a rapid detection method that can be used even in resource-poor countries is urgently required to control this global public health threat. Conventional techniques, such as bacterial culture and polymerase chain reaction (PCR, are insufficient to combat this threat because they are time-consuming and laborious. In this study, we developed a loop-mediated isothermal amplification (LAMP method for detecting blaOXA-23-positive CRAb, the most prevalent form of CRAb in Asia, especially in Thailand, and confirmed its efficacy as a surveillance tool in a clinical setting. Clinical samples of sputum and rectal swabs were collected from patients in a hospital in Bangkok and used for LAMP assays. After boiling and centrifugation, the supernatants were used directly in the assay. In parallel, a culture method was used for comparison purposes to evaluate the specificity and sensitivity of LAMP. As a first step, a total of 120 sputum samples were collected. The sensitivity of LAMP was 88.6% (39/44, and its specificity was 92.1% (70/76 using the culture method as the "gold standard". When surveillance samples including sputum and rectal swabs were analyzed with the LAMP assay, its sensitivity was 100.0%. This method enables the direct analysis of clinical specimens and provides results within 40 minutes of sample collection, making it a useful tool for surveillance even in resource-poor countries.

  12. Sefaperazon-sulbaktam, imipenem ve sefepimin antibiyoterapi etkinliklerinin çoğul dirençli ve duyarlı acinetobacter baumannii ile oluşturulan deneysel ikili apse modelinde karşılaştırılması Assesment of efficacies of imipenem, cefoperazone-sulbactam and cefepim in rats with experimental thigh abscess model due to multidrug resistant and sensitive acinetobacter baumannii strains

    OpenAIRE

    Yıldırım, Mustafa İshak

    2006-01-01

    Hastane infeksiyonları morbidite ve mortalitesinin yüksek olması, hastanede kalış süresini uzatması ve yüksek tedavi maliyeti nedeniyle önemli bir sağlık sorunudur. Son yıllarda özellikle yoğun bakım üniteleri başta olmak üzere hastane infeksiyonlarında en sık izole edilen etkenlerin başında Acinetobacter cinsi bakteriler gelmektedir. Bunlar içerisinde hastane infeksiyonlarında en sık izole edilen köken A. baumannii'dir. Acinetobacter infeksiyonlarının tedavisinde en önemli problem çoğul dire...

  13. Colistin-resistant, lipopolysaccharide-deficient Acinetobacter baumannii responds to lipopolysaccharide loss through increased expression of genes involved in the synthesis and transport of lipoproteins, phospholipids, and poly-β-1,6-N-acetylglucosamine.

    Science.gov (United States)

    Henry, Rebekah; Vithanage, Nuwan; Harrison, Paul; Seemann, Torsten; Coutts, Scott; Moffatt, Jennifer H; Nation, Roger L; Li, Jian; Harper, Marina; Adler, Ben; Boyce, John D

    2012-01-01

    We recently demonstrated that colistin resistance in Acinetobacter baumannii can result from mutational inactivation of genes essential for lipid A biosynthesis (Moffatt JH, et al., Antimicrob. Agents Chemother. 54:4971-4977). Consequently, strains harboring these mutations are unable to produce the major Gram-negative bacterial surface component, lipopolysaccharide (LPS). To understand how A. baumannii compensates for the lack of LPS, we compared the transcriptional profile of the A. baumannii type strain ATCC 19606 to that of an isogenic, LPS-deficient, lpxA mutant strain. The analysis of the expression profiles indicated that the LPS-deficient strain showed increased expression of many genes involved in cell envelope and membrane biogenesis. In particular, upregulated genes included those involved in the Lol lipoprotein transport system and the Mla-retrograde phospholipid transport system. In addition, genes involved in the synthesis and transport of poly-β-1,6-N-acetylglucosamine (PNAG) also were upregulated, and a corresponding increase in PNAG production was observed. The LPS-deficient strain also exhibited the reduced expression of genes predicted to encode the fimbrial subunit FimA and a type VI secretion system (T6SS). The reduced expression of genes involved in T6SS correlated with the detection of the T6SS-effector protein AssC in culture supernatants of the A. baumannii wild-type strain but not in the LPS-deficient strain. Taken together, these data show that, in response to total LPS loss, A. baumannii alters the expression of critical transport and biosynthesis systems associated with modulating the composition and structure of the bacterial surface. PMID:22024825

  14. Insufficient Discriminatory Power of Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry Dendrograms to Determine the Clonality of Multi-Drug-Resistant Acinetobacter baumannii Isolates from an Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    John Hoon Rim

    2015-01-01

    Full Text Available While pulsed-field gel electrophoresis (PFGE is recognized as the gold standard method for clonality analysis, MALDI-TOF MS has recently been spotlighted as an alternative tool for species identification. Herein, we compared the dendrograms of multi-drug-resistant (MDR Acinetobacter baumannii isolates by using MALDI-TOF MS with those by using PFGE. We used direct colony and protein extraction methods for MALDI-TOF MS dendrograms. The isolates with identical PFGE patterns were grouped into different branches in MALDI-TOF MS dendrograms. Among the isolates that were classified as very close isolates in MALDI-TOF MS dendrogram, PFGE band patterns visually showed complete differences. We numeralized similarity among isolates by measuring distance levels. The Spearman rank correlation coefficient values were 0.449 and 0.297 between MALDI-TOF MS dendrogram using direct colony and protein extraction method versus PFGE, respectively. This study is the first paper focusing solely on the dendrogram function of MALDI-TOF MS compared with PFGE. Although MALDI-TOF MS is a promising tool to identify species in a rapid manner, our results showed that MALDI-TOF MS dendrograms could not substitute PFGE for MDR Acinetobacter baumannii clonality analysis.

  15. Analysis of Acinetobacter Baumannii Infection and Drug Resistance in a Hospital in 2009%某院2009年鲍曼不动杆菌感染及耐药情况分析

    Institute of Scientific and Technical Information of China (English)

    牟洪; 杨思芸; 王凤; 李胜前; 苏强; 杨晓萌

    2011-01-01

    OBJECTIVE: To provide basis for rational use of antibiotic in the treatment of acinetobacter baumannii infection. METHODS: The basic information, drug susceptibility and the use of antibiotics in patients with acinetobacter baumanii infection in a class three grade A hospital in 2009 were analyzed retrospectively. RESULTS: 141 cases of acinetobacter baumannii infection mainly distributed in the ICU (48.94%), neurosurgery department ( 12.77% ) and respiration department ( 11.35% ). Most patients suffered from severe primary diseases or poor immune function. Acinetobacter baumannii had the lowest resistance rate to cefoperazone/sulbactam (0.0%), followed by imipenem (3.0%). The drug resistance rate of acinetobacter baumannii to piperacillin/tazobactam, ceftazidime, vefepime and levofloxacin were 96.7%, 90.9%, 92.4% and 51.9%, respectively. Drugs in the first place of experience administration list was piperacillin/tazobactam, followed by levofloxacin and cefpiramide. After reporting drug susceptibility, imipenem was adopted mostly, followed by levofloxacin and piperacillin/tazobactam. Single drug therapy was the main therapeutic regimen, followed by two-drug therapy. CONCLUSION: Acinetobacter baumanii has serious multiple drug resistance to antibiotics. Cefoperazone/sulbactam or imipenem can be used for thrapy.%目的:为临床合理使用抗菌药物治疗鲍曼不动杆菌感染提供依据.方法:对某"三甲"医院2009年鲍曼不动杆菌感染患者的基本资料、药敏情况、抗菌药物使用情况进行回顾性统计分析.结果:141例鲍曼不动杆菌感染患者主要分布在重症监护病房(48.94%)、神经外科(12.77%)、呼吸内科(11.35%);感染患者大多存在严重原发病或免疫功能低下;鲍曼不动杆菌对头孢哌酮/舒巴坦钠耐药率最低(0.0%),其次是亚胺培南(3.0%),对哌拉西林/他唑巴坦、头孢他啶、头孢吡肟、左氧氟沙星的耐药率分别为96.7%、90.9%、92.4%、51.9%;

  16. Analysis on drug resistance in 404 strains of Acinetobacter Baumannii isolated from Neurosurgery wards%神经外科病房404株鲍曼不动杆菌的耐药性分析

    Institute of Scientific and Technical Information of China (English)

    郭黎; 郭晓兰; 邓健康

    2016-01-01

    Objective To investigate the specimen source and drug resistance in the strains of Acinetobacter baumannii isolated from the submitted samples in the neurosurgery wards of our hospital during 2011-2014 in order to provide the reference for clini‐cal treatment and nosocomial infection control .Methods A retrospective analysis was performed on the clinical data of clinical dis‐tribution and antibacterial drugs sensitivity in 404 non‐repeated strains of Acinetobacter baumannii isolated from the samples of neurosurgical patients .Results The mainly specimen source of Acinetobacter baumannii isolated from neurosurgical patients was sputum and cerebrospinal fluid ,accounting for 89 .1% and 7 .9% respectively .Acinetobacter baumannii isolates showed the lowest resistance rates to minocycline and cefoperazone/sulbactam (28 .6% and 31 .8% respectively) .The resistance rates to imipenem and meropenem were 79 .4% and 83 .2% respectively ;the resistance rate to other antibacterial drugs exceeded 69 .0% .Conclusion Acinetobacter baumanii strains isolated from the neurosurgery department have higher resistance rates to many kinds of antibacteri‐al agents ,minocycline and cefoperazone/sulbactam still has good in vitro antibacterial activity against Acinetobacter baumanii .Clinic should strengthen the management of antibacterial agents ,increases the rate of drug susceptibility test and rationally uses the anti‐bacterial drugs .%目的:了解2011~2014年从川北医学院附属医院神经外科病房送检标本中分离的鲍曼不动杆菌的标本来源和耐药状况,为临床治疗和医院感染控制提供依据。方法对404株非重复鲍曼不动杆菌的临床分布和抗菌药物敏感性资料进行回顾性分析。结果从神经外科患者标本中分离的鲍曼不动杆菌89.1%来自痰液,7.9%来自脑脊液。鲍曼不动杆菌对米诺环素和头孢哌酮/舒巴坦的耐药率最低,分别为28.6%和31.8%;对亚胺

  17. Clinical distribution and drug resistance of Acinetobacter baumannii%鲍氏不动杆菌的临床分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    胡蓉蓉; 马小琴; 张能华; 王静

    2014-01-01

    OBJECTIVE To understand the separation rate and area distribution and drug resistance changing of A cinetobacter baumani in in clinics ,so as to provide the basis for clinical rational drug use .METHODS A total of 2412 strains of A .baumani from inpatients clinical samples during 2008 to 2012 were collected ,to understand the distribution and drug resistance of it .The susceptibility test was performed by K-B method .The interpretation of the results was based on the CLSI 2010 .WHONET 5 .4 and EXcellsoftware were used for bacterial distribution and drug resistance analysis .RESULTS Among 2412 strains of A .baumannii ,81 .50% were from sputum speci-mens ,77 .10% specimens from patients in ICU ward .Separation rate in 2008 was 5 .13% and increased by 9 .91%in 2012 ,which was on the rise .The resistance rate of A .baumani to aztreonam and ciprofloxacin was higher than 90% .The drug resistance respectively to imipenem , meropenem and cefoperazone/sulbactam was also from 13 .9% and 8 .6% in 2008 to 51 .6% ,55 .3% and 48 .3% .The drug resistance of A .baumannii to 16 kinds of an-timicrobial drugs was in a rising trend year by year ,and part shows the characteristics of multiple drug resistance . CONCLUSION The situation of drug resistance of Acinetobacter baumannii is becoming more and more serious , the monitoring and management of multi-drug resistant bacteria should be strengthened ,also rational use of antibi-otics ,stricting disinfection and quarantine system need to obey to prevent hospital infections ,avoid unnecessary invasive operation ,improve the immune system ,and prevent A cinetobacter baumannii nosocomial infection and outbreak .%目的:了解鲍氏不动杆菌在临床的分离率和病区分布及耐药性变迁,为临床合理用药提供参考依据。方法收集2008-2012年医院住院患者临床标本分离出的2412株鲍氏不动杆菌,了解其分布特点及耐药性,采用K-B法进行药敏试验,结果判定参照美国临

  18. 呼吸道161株鲍曼不动杆菌的临床分布及耐药性分析%Clinical distribution and drug resistance analysis of 161 strain Acinetobacter baumannii in respiratory tract

    Institute of Scientific and Technical Information of China (English)

    温燕; 陆华; 唐双意; 杨天燕; 蒋霞

    2013-01-01

    目的 了解痰液标本分离的鲍曼不动杆菌的临床分布及对各种常用抗菌药物的耐药情况,为临床合理治疗提供依据.方法 从2011年1月至12月广西医科大学第一附属医院患者的痰液标本中分离出161株鲍曼不动杆菌,采用WHONET 5.4软件对数据进行统计分析.结果 在161株鲍曼不动杆菌标本中,其临床分布以重症监护病房为主(47.83%),其次为内科(24.23%)和外科(13.04%);鲍曼不动杆菌对常用抗菌药物的耐药率以头孢哌酮/舒巴坦最低(6.21%),其次为亚胺培南/西司他丁及美罗培南(分别为46.58%、47.83%);哌拉西林、哌拉西林/他唑巴坦、头孢他啶、安曲南、庆大霉素、阿米卡星、环丙沙星、左氧氟沙星、复方磺胺甲噁唑及头孢吡肟等的耐药率均在50%以上.结论 鲍曼不动杆菌主要分布于各重症监护病房,对多种常见抗生素耐药率有升高趋势,提示临床应加强抗生素的合理应用,防止耐药率进一步增长.%Objective To investigate the clinical distribution and the drug resistance to various antibacterials of Acinetobacter baumannii from sputum specimen,and provide reference for the clinical rational therapy.Methods The 161 strain Acinetobacter baumaniis were separated from sputum specimen of patients in the First Affiliated Hospital of Guangxi Medical University from January to December in 2011,and the data were analyzed by WHONET 5.4 software.Results Among the 161 specimens of Acinetobacter baumannii,the dominant clinical distribution was intensive care unit(47.83%)followed by medical department(24.23%)and surgery department(13.04%).The drug resistance rate of Acinetobacter baumanii to cefoperazone/sulbactam was the lowest (6.21%),then was the i mipenem/cilastatin (46.58 %)and meropenem (47.83 %).The drug resistance rates of Acinetobacter baumanii to piperacilli,piperacilli

  19. [Tigecycline: CMI 50/90 towards 1766 Gram-negative bacilli (3rd generation cephalosporins resistant enterobacteriaceae), Acinetobacter baumannii and Bacteroides fragilis group, University Hospital - Montpellier, 2008-2011].

    Science.gov (United States)

    Froment Gomis, P; Jean-Pierre, H; Rousseau-Didelot, M-N; Compan, B; Michon, A-L; Godreuil, S

    2013-12-01

    Tigecycline is a new glycylcyclin with a wide spectre including multi-resistant bacteria. Our laboratory tests in routine the in vitro activity of the TGC towards clinically significant isolates of 3rd generation cephalosporins resistant enterobacteriaceae (EC3R), Acinetobacter baumannii and Bacteroides fragilis group (BFG). The objective of this study is to describe the in vitro activity of TGC against these strains isolated between 2008 and 2011 in the university hospital of Montpellier. In this study period, 1070 isolates EC3R including 541 extended spectrum β-lactamase-producers (ESBL) strains, 47 isolates of A. baumannii including 40 multi-resistant isolates and 645 isolates of BFG were tested. Minimum inhibitory concentrations (MIC) were determined using the E-test method. TGC was active against 86.2% of EC3R with a MIC 90 less or equal to 1mg/L (Escherichia coli being the most sensitive species). A. baumannii and BFG were also inhibited at low concentrations of TGC with a MIC 90 less or equal to 2mg/L respectively for 47% and 84.2% of the isolates. Our study confirms the activity of TGC against the EC3R including ESBL-producers strains. The relevance of the therapeutic use of TGC on the BFG isolates with a MIC greater than 2mg/L should be better documented. Often prescribed in therapeutic impasse, the proper use of TGC would require: clarifying the threshold of sensitivity for some species (i.e., A. baumannii, Bacteroides fragilis group); a better understanding of correlation between in vitro and in vivo activity.

  20. 老年病房鲍氏不动杆菌感染的分布及耐药性分析%Distribution and antimicrobial resistance of Acinetobacter baumannii infection in elderly ward

    Institute of Scientific and Technical Information of China (English)

    洪在姣

    2012-01-01

    Objective:To investigate'the distribution and antimicrobial resistance of Acinetobacter baumannii ( ABA) infection in the elderly patients in our hospital. Methods; 126 strains of A. baumannii, isolated from elderly patients with infection from Jan. 2008 to Dec. 2010, were collected and antimicrobial susceptibility test was performed. Results; AH strains of A. baumannii were from sputum, urine, pus, etc; the resistance rate to cefopera-zone/sulbactam was lowest (3. 3% ) , followed by ampicillin/sulbactam( 12.7% ) and imipenem(25. 8% ) , and the resistant rate to SMZ - TMP(73.2% ) was highest. Conclusion; The antimicrobial resistance of A. baumannii in the elderly patients was high, the antibiotic treatment must depend on antimicrobial susceptibility test.%目的:探讨老年患者鲍氏不动杆菌感染的分布特征及耐药性.方法:对我院2008年1月-2010年12月期间老年患者感染的鲍氏不动杆菌、患者基础疾病及其对15种抗菌药物的药敏结果进行分析.结果:检出126株鲍氏不动杆菌,标本来自痰液、尿液、分泌物、脓液等.耐药率最低为头孢哌酮/舒巴坦(3.3%)、其次为氨苄西林/舒巴坦(12.7%)、亚胺培南(25.8%),耐药率最高为复方SMZ.结论:老年患者感染的鲍氏不动杆菌耐药率较高,应根据药敏试验结果合理选择抗菌药物.

  1. Prevalence of Genes of OXA-23 Carbapenemase and AdeABC Efflux Pump Associated with Multidrug Resistance of Acinetobacter baumannii Isolates in the ICU of a Comprehensive Hospital of Northwestern China

    Directory of Open Access Journals (Sweden)

    Wei Jia

    2015-08-01

    Full Text Available The objective of this study was to explore the molecular epidemiology and the genetic support of clinical multidrug resistant (MDR Acinetobacter baumannii (A. baumannii isolates in an ICU ward of a comprehensive hospital. A total of 102 non-duplicate drug-resistant A. baumannii isolates were identified and 93 (91.1% of them were MDR strains. Molecular analysis demonstrated that carbapenemase genes blaOXA-23 and blaOXA-51 were presented in all 93 MDR isolates (100%, but other carbapenemase genes, including blaOXA-24, blaOXA-58, blaIMP-1, blaIMP-4, blaSIM, and blaVIM genes were completely absent in all isolates. In addition, genes of AdeABC efflux system were detected in 88.2% (90/102 isolates. Interestingly, an addition to efflux pump inhibitor, reserpine could significantly enhance the susceptibility of MDR isolates to moxifloxacin, cefotaxime, and imipenem (p < 0.01. Clonal relationship analysis further grouped these clinical drug-resistant isolates into nine clusters, and the MDR strains were mainly in clusters A, B, C, and D, which include 16, 13, 25, and 15 isolates, respectively. This study demonstrated that clinical isolates carrying carbapenemase-encoding genes blaOXA-23 and AdeABC efflux pump genes are the main prevalent MDR A. baumannii, and the co-expression of oxacillinase and efflux pump proteins are thus considered to be the important reason for the prevalence of this organism in the ICU of this hospital.

  2. Bulgecin A as a β-lactam enhancer for carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Acinetobacter baumannii clinical isolates containing various resistance mechanisms

    Directory of Open Access Journals (Sweden)

    Skalweit MJ

    2016-09-01

    Full Text Available Marion J Skalweit,1–5 Mei Li2 1Department of Medicine, 2Research Section, 3Infectious Diseases Section, Louis Stokes Cleveland Department of Veterans, 4Department of Medicine, 5Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH, USA Abstract: Genetic screening of Pseudomonas aeruginosa (PSDA and Acinetobacter ­baumannii (ACB reveals genes that confer increased susceptibility to β-lactams when disrupted, suggesting novel drug targets. One such target is lytic transglycosylase. Bulgecin A (BlgA is a natural product of Pseudomonas mesoacidophila and a lytic transglycosolase inhibitor that works synergistically with β-lactams targeting PBP3 for Enterobacteriaceae. BlgA also weakly inhibits di-Zn2+ metallo-β-lactamases like L1 of Stenotrophomonas maltophilia. We hypothesized that because of its unique mechanism of action, BlgA could restore susceptibility to carbapenems in carbapenem-resistant PSDA (CR-PSDA and carbapenem-resistant ACB, as well as ACB resistant to sulbactam. A BlgA-containing extract was prepared using a previously published protocol. CR-PSDA clinical isolates demonstrating a variety of carbapenem resistance mechanisms (VIM-2 carbapenemases, efflux mechanisms, and AmpC producer expression were characterized with agar dilution minimum inhibitory concentration (MIC testing and polymerase chain reaction. Growth curves using these strains were prepared using meropenem, BlgA extract, and meropenem plus BlgA extract. A concentrated Blg A extract combined with low concentrations of meropenem, was able to inhibit the growth of clinical strains of CR-PSDA for strains that had meropenem MICs ≥8 mg/L by agar dilution, and a clinical strain of an OXA-24 producing ACB that had a meropenem MIC >32 mg/L and intermediate ampicillin/sulbactam susceptibility. Similar experiments were conducted on a TEM-1 producing ACB strain resistant to sulbactam. BlgA with ampicillin/sulbactam inhibited the growth

  3. Analysis of clinical characteristics and drug resistance of 224 strains of Acinetobacter baumannii infection%224例鲍曼不动杆菌感染的临床特征及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    徐薛芬; 徐爱晖

    2013-01-01

    目的 了解我院224例鲍曼不动杆菌感染的临床特征及耐药性.方法 采用常规方法进行细菌培养、菌株鉴定及药敏检测.结果 201名患者共分离出224株鲍曼不动杆菌,患者主要集中在ICU(33.8%)、外科(25.9%)、呼吸内科(14.4%)、骨科(6.1%),基础疾病以呼吸系统疾病(64.2%)、心血管系统疾病(30.8%)、神经系统疾病(29.8%)及糖尿病(22.9%)多见,与手术治疗及有创检查治疗(56.7%)、联合使用≥2种抗生素(80.6%)及使用时间≥15天(38.8%)可能存在相关性.224株鲍曼不动杆菌对米诺环素敏感性最高(66.1%),对美罗培南、氨苄西林/舒巴坦、头孢哌酮/舒巴坦敏感性超过55%.结论 鲍曼不动杆菌感染与患者有基础疾病、有创性检查治疗及使用广谱抗生素及时间过长有关,其耐药情况严重,多重耐药及泛耐药菌株日益增多,目前对米诺环素、舒巴坦、碳青酶烯类抗生素仍保持相对敏感性,临床应根据药敏结果合理选择使用抗生素.%Objective To investigate the clinical charateristics of infection of 224 Acinetobacter baumannii strains, and to analyze drug resistance of Acinetobacter baumannii strains. Methods The isolation of the bacterium was conducted according to the microorganical method of CLSI ( Clinical and Laboratory Standards Institute ). American DATE Company MicroScan Walkway-40 automatic analyzer was applied to identification and drug susceptibility test. Drug resistance was calculated with WH0NET5. 4 soitware. Results A total of 224 strains of Acinetobacter baumannii were isolated from 201 patients. The patients were mainly from ICU( intensive care uint) ( 33. 8% ), department of surgery ( 25. 9% ), department of respiratory medicine ( 14. 4% ), department of orthopedics ( 6. 1% ). Common underlying diseases were pulmonary diseases ( 64. 2% ), cardiovascular diseases ( 30. 8% ), diseases of nervous system ( 29. 8% ) and diabetes ( 22. 9% ). 56. 7% of the patients had

  4. Observation on Ultraviolet Irradiation on Multi-drug Resistant Acinetobacter Baumannii in the Killing Effect under Different Humidity%紫外线对多药耐药鲍曼不动杆菌杀灭效果观察

    Institute of Scientific and Technical Information of China (English)

    王云凤; 刘奕

    2012-01-01

    Objective To investigate the killing effect of ultraviolet irradiation on multi-drug resistant Acinetobacter bauman-nii. Methods In the "dry" environment, Acinetobacter bauraannii was inoculated on nutrient agar medium with multi-drug resistant, and placed in UV lamp 0.6 m,l m,2 m,irradiation at different times to observe the killing effect. Results In the "dry" environmental conditions, Acinetobacter baumannii was exposured to UV lamp 0. 6 m for 8 min, the ultraviolet light 1 m,2 m light for 120 min and 30 min,poured nutrient agar,35 °C 48 h culture sterile growth;direct inoculation of bacteria in nutrient agar medium , ultraviolet light irradiation 49 min 0.6m sterile growth; ultraviolet light 1 m,2 m 30 min and 120 min, there existed bacteri-a growth. Conclusion In the "dry" environment,the conventional method of ultraviolet disinfection can kill multi-drug resistant Acinetobacter baumannii; in the humid environment, conventional UV disinfection methods can not completely kill multi-drug resistant Acinetobacter baumannii, even if the extension exposure time can not achieve the desired sterilization; only shorten the distance of irradiation and extend the time before UV irradiation can completely kill the bacteria.%目的 了解紫外线照射对多药耐药鲍曼不动杆菌的杀灭效果.方法 将“干燥”环境下和接种于营养琼脂培养基上的多药耐药鲍曼不动杆菌,分别置于紫外线灯下0.6m、1 m、2m,照射不同时间,观察杀灭效果.结果 在“干燥”环境条件下多药耐药鲍曼不动杆菌于紫外线灯下0.6m照射8 min,于紫外线灯下1 m、2 m照射120 min和30 min后,倾注营养琼脂,35℃培养48 h均无菌生长;细菌直接接种于营养琼脂培养基上,紫外线灯下0.6m照射49 min无菌生长;紫外线灯下1 m、2m照射30 min和120 min均有菌生长.结论 “干燥”环境下,常规的紫外线消毒方法可杀灭多药耐药鲍曼不动杆菌;高湿环境下,常规紫外线

  5. ANTIBACTERIAL ACTIVITY OF ESSENTIAL OIL OF CYMBOPOGON FLEXUOSUS (LEMON GRASS AGAINST CLINICAL ISOLATES OF MULTIDRUG-RESISTANT ACINETOBACTER BAUMANNII : A PRELIMINARY IN-VITRO STUDY

    Directory of Open Access Journals (Sweden)

    Aparna S

    2015-05-01

    Full Text Available Aim – In recent years, the incidence of nosocomial infections due to A.baumannii has increased to a point of concern. Rapid spread of multidrug and extremely drug resistant A.baumannii in clinical settings has made treatment options difficult for clinician. It has also in creased the morbidity and mortality in immunocompromised patients. The aim of this study was to investigate the ef ficacy of essential oil of a traditional medicinal plant, Cymbopogon flexuosus (lemon grass against the problematic multidrug resistant A.baumannii . Methodology – Essential oil of lemon grass was distilled by Neo-Clav enger’s method and the antibacterial activity was tested against 102 multidrug resistant A.baumannii clinical isolates by punch-well and disc diffusion methods. The minimum inhibitory concentration of lemon grass oil was determined by Macrobroth dilution method. Results – Majority of A.baumannii isolates were inhibited by lemon grass oil, inhibition zone ranging from 13mm to 33mm, mean inhibition zone being 23mm and the minimum inhib itory concentration of lemon grass oil was 6.25μl/ml. Conclusion – essential oil lemon grass showed good antibacterial activity against A.baumannii and might be considered as an alternative treatment option against multi-drug resistant A.baumannii infections. However, further pharmacokinetic and pharmacodynamic studies are needed for routine clinical use.

  6. 替加环素对鲍曼不动杆菌作用研究的文献计量分析%Literature measurement analysis of tigecycline against Acinetobacter baumannii role in research

    Institute of Scientific and Technical Information of China (English)

    白艳; 王瑾; 谷彩梅; 刘斌; 曹江; 梅和坤; 江学维; 牛卉; 王睿

    2014-01-01

    Objective To analyze researches and hot issuses on tigecy-cline against Acinetobacter baumannii around the world.Methods Liter-atures were searched in Pubmed , Embase , Web of Science , and CNKI from the beginning to March , 2014.Endnote7.0 was used to sort out and summarize.Results A total of 227 English articles and 34 Chinese arti-cles were collected and the majority was characterized asoriginal article.Those articles were focused on the basic research of tigecycline against Acinetobacter baumannii in vitro, animal experiments and case analysis.Resistance mechanism , drug susceptibility test in vitro, and drug combi-nation were frequently involved.Conclusion The study on tigecycline against Acinetobacter baumannii increasingly has attracted global concern , especially the study on resistance mechanisms to tigecycline has gone fur-ther.%目的:了解国内外替加环素作用于鲍曼不动杆菌的研究动态及热点内容。方法检索从建库至2014-03的Pubmed、Embase、Web of Science及CNKI数据库中替加环素对鲍曼不动杆菌作用相关文献;用Endnote7.0软件进行分类整理分析。结果纳入英文文献227篇,中文文献34篇;发表的文献类型以论著为主;文献的主要内容为替加环素对鲍曼不动杆菌作用相关的体外基础研究、动物实验、病例分析等;研究内容主要涉及耐药机制、体外药敏实验及联合用药等。结论替加环素作用于鲍曼不动杆菌的研究受到广泛关注,尤其是鲍曼不动杆菌对替加环素耐药机制的研究愈加深入。

  7. Clinical analysis of Acinetobacter baumannii blood stream infections in 25 patients%25例鲍氏不动杆菌血流感染临床分析

    Institute of Scientific and Technical Information of China (English)

    陈柱; 张丽; 李媛媛; 韩娜; 张民伟

    2013-01-01

    目的 探讨鲍氏不动杆菌血流感染的临床学及细菌学特点,为临床治疗鲍氏不动杆菌血流感染提供指导.方法 对医院2010年1月—2011年12月25例鲍氏不动杆菌血流感染患者的临床资料及细菌学资料进行统计分析.结果 25例鲍氏不动杆菌血流感染患者主要来自ICU、呼吸科,两者占72.0%;平均年龄63岁;21例患者住院>2周,占84.0%,住院>1个月12例,占48.0%;存在侵入性操作占72.0%,死亡率28.0%;药敏结果显示,替加环素敏感性最高,达100.0%,其次是阿米卡星,敏感性>90.0%,其他抗菌药物敏感率均<40.0%;14例泛耐药,占56.0%;泛耐药与非泛耐药菌株比较,血培养阳性前两周内使用碳青霉烯类抗菌药物及侵入性操作差异有统计学意义(P<0.05).结论 鲍氏不动杆菌血流感染出现泛耐药菌株比例高,患者病死率高;高龄、侵入性操作、住院时间>2周是常见易感因素,使用碳青霉烯类抗菌药物及侵入性操作是发生泛耐药病例的高危因素.%OBJECTIVE To study the clinical and bacteriological characteristics of bloodstream infections caused by Acinetobacter baumannii so as to guide the clinical treatment of the bloodstream infections. METHODS The clinical and bacteriological characteristics of 25 patients with bloodstream infections caused by A. baumannii in the hospital from Jan 2010 to Dec 2011 were statistically analyzed. RESULTS Totally 25 patients with the bloodstream infections mainly distributed in ICU and the respiratory department, accounting for 72. 0%. The average age was 63 years old. There were 21 (84. 0%) cases of patients with the length of hospital stay more than 2 weeks and 12 (48. 0%) cases of patients with the length of hospital stay more than one month. The patients who underwent the invasive operation accounted for 72. 0% ,the mortality was 28. 0%. The antimicrobial susceptibility testing result showed that the drug

  8. 鲍曼不动杆菌371株感染特征及耐药性分析%The infection and drug resistance characteristics of 371 cases of acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    马春燕

    2011-01-01

    Objective To analyze hospital isolated from 371 acinetobacter baumannii the distribution of the infection characteristics and drug resistance.Methods Of the first people's hospital of Kaifeng the samples of isolated 371 acinetobacter baumannii was selected,according to the " national clinical laboratory operating procedures,"the third edition of the conventional culture isolation,identification of bacteria using the French company bioMérieux VITEK-32 microbial automatic analyzer and GNI + cards for identification.France bioMérieux VITEK2 using automated microbial analysis system and supporting the identification and drug Minka for bacterial identification and susceptibility testing ( MIC method),drug susceptibility results in the standard to judge by CLSI2006.Using the World Health Organization drug monitoring network provided WHONET 5.0 software for data analysis.Results 315 sputum detected,accounting for 84.9% ; pleural effusion 32,8.6% ;pus 21,5.7% ;urine 3,0.8%.Respiratory Medicine,124,33.4% ;Geriatrics 81,21.8%.Of acinetobacter baumannii resistance to minocycline was the lowest (3%),the highest resistance to azithromycin( 100% ).Conclusion The pan-resistant Acinetobacter baumannii,minocycline as a drug of choice,imipenem could be used as first-line drugs.%目的 分析鲍曼不动杆菌的分布规律、感染特征及耐药性.方法 选取开封市第一人民医院送检标本中分离出的鲍曼不动杆菌371株,常规培养分离鉴定.采用法国生物梅里埃公司VITEK2全自动微生物分析系统及其配套的鉴定和药敏卡进行细菌鉴定和药敏试验(MIC法),药敏结果按CLSI 2006年标准判断.采用世界卫生组织耐药监测网提供的WHONET 5.0软件进行数据分析.结果 痰液检出315株,占84.9%;胸腔积液32株,占8.6%;脓液21株,占5.7%;尿液3株,占0.8%.呼吸内科124株,33.4%;老年病科81株21.8%.对鲍曼不动杆菌耐药性最低的是米诺环素(3.0%),耐

  9. 磷霉素联合左氧氟沙星对鲍曼不动杆菌生物膜的体外研究%Effect of fosfomycin combined with levofloxacin on Acinetobacter baumannii biofilm

    Institute of Scientific and Technical Information of China (English)

    晏奎; 温汉春; 陈一强; 梁宏洁; 李萌; 闵利

    2015-01-01

    目的:探讨磷霉素( FOS)对鲍曼不动杆菌生物膜的破坏作用以及与左氧氟沙星( LFX)的联合杀菌效果。方法选取临床分离鲍曼不动杆菌菌株构建体外生物膜模型,微量肉汤稀释法测定FOS及LFX的最低抑菌浓度( MIC ),连续稀释法测定生物膜内活菌计数,结晶紫染色法半定量生物膜。用单因素方差分析进行统计处理。结果生物膜经抗生素作用24 h后,生物膜半定量显示,FOS组及FOS+LFX组吸光度值均少于空白对照组,差异有统计学意义( P<0.01);但LFX组吸光度值与空白对照组比较,差异无统计学意义。 FOS组及LFX组的生物膜内活菌计数与空白对照组比较,差异无统计学意义;FOS+LFX组第4,8,24 h膜内活菌计数均少于空白对照组( P<0.01)。结论 FOS能破坏鲍曼不动杆菌已形成的生物膜,并可增强LFX对生物膜内鲍曼不动杆菌的清除作用。%Objective To observe the in vitro destructive effect of fos-fomycin ( FOS ) on the biofilm of Acinetobacter baumannii and the synergistic antibacterial activity in combination with levofloxacin ( LFX) .Methods The biofilm model was established by clinical isolates of Acinetobacter baumannii -48876 as the study strain.The minimum inhibitory concentrations ( MIC ) of FOS and LFX were measured by doubling dilution. The viable count of biofilm carrier were determined by continuous dilution method and the biofilm quanti-tation by crystal violet staining method.Data were analyzed by single factor analysis of variance ( One-Way ANVOA).Results When the biofilm being reacted with antibiotic for 24 hours, the quantitation of biofilm showed the absorbances of FOS group and FOS plus LFX group were significantly less than that of the control group ( P<0.01 ) .While there was no statistical difference found in absor-bance value in LFX group and the control group.At the 4 th , 8 th and 24 th hour, the number of

  10. Impact of rapid identification of Acinetobacter Baumannii via matrix-assisted laser desorption ionization time-of-flight mass spectrometry combined with antimicrobial stewardship in patients with pneumonia and/or bacteremia.

    Science.gov (United States)

    Wenzler, Eric; Goff, Debra A; Mangino, Julie E; Reed, Erica E; Wehr, Allison; Bauer, Karri A

    2016-01-01

    We evaluated the clinical and economic outcomes of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) with stewardship intervention in patients with Acinetobacter baumannii (AB) pneumonia and/or bacteremia. 66 patients were included in the pre-intervention group and 53 in the intervention group. The combination of AB identification via MALDI-TOF MS and ID PharmD intervention significantly reduced the median time to effective therapy compared to conventional identification without intervention [77.7 (95% CI: 73.1-84.8) to 36.6 (95% CI: 25.9-50.9) hours (P timely, effective antimicrobial therapy and is associated with increased clinical cure.

  11. Research on six genes and insertion sequence ISAbal of carbopenems-resistant Acinetobacter baumannii%耐碳青霉烯类鲍曼不动杆菌6种基因及ISAbal插入序列的研究

    Institute of Scientific and Technical Information of China (English)

    廖晚珍; 杨璐; 温桂兰; 彭卫华; 胡雪飞; 余阳

    2012-01-01

    Objective To study the relationship between the genotype characteristics and insertion sequence ISAbal of carbopenems resistant Acinetobacter baumannii ( CRAB) ,and investigate the drug resistant mechanism. Methods A total of 70 strains of CRAB (no repeat strains) and 10 strains of carbopenems-sensitive Acinetobacter baumannii were collected. Metalloenzyme beta-lactamase (MBLs) were detected by 2-mercaptopropionic acid inhibition test. The blaIMP,blaVIM,blaOXA-23,blaOXA-24,blaOXA-51,blaOXA-58 and ISA balOXA-23 were amplified by multiplex polymerase chain reaction (PCR). The amplified products were measured for DNA sequence . Results The synergy tests were negative (MBLs negative ) by 2-mercaptopropionic acid and ceftazime in 70 strains of CRAB. Through 7 pairs of specific primers,70 strains of CRAB and 10 strains of carbopenems-sensitive Acinetobacter baumannii were determined for PCR amplification. All the CRAB strains carried blaOXA-23 and blaOXA-51,but blaOXA-24 was never detected. Only 1 strain carried blaOXA-58,and the 80 strains did not carry blaIMP and blaVIM In addition,all the CRAB strains carried insertion sequence ISAbalOXA-23,however,all the sensitive strains did not carry. Conclusions Major genes are blaOXA-51 and blaOXA-23 in the CRAB strains. Insertion sequence ISAbal is located in the upstream of blaOXA-23. There is no correlation among drug-resistance of Acinetobacter baumannii to MBLs,blaOXA-24 and blaOXA-58.%目的 研究耐碳青霉烯类鲍曼不动杆菌(CRAB)的基因型特点和与插入序列ISAbal的关系,探讨其耐药机制.方法 收集CRAB 70株(非重复)和碳青霉烯类敏感鲍曼不动杆菌10株,采用2-巯基丙酸抑制试验检测金属β-内酰胺酶(MBLs);采用多重聚合酶链反应(PCR)扩增blaIMP、blaVIM、blaOXA-23、blaOXA-24、blaOXA-51、blaOXA-58、ISAbalOXA-23,扩增产物DNA测序进行比对.结果 70株CRAB 2-巯基丙酸与头孢他啶协同试验全部为阴性(即MBLs阴性),用7对特异性引物对70

  12. Nuevas alternativas terapéuticas frente a acinetobacter baumannii. Estudios pre-clínicos de péptidos híbridos de cecropina A-melitina, una quinolona de nueva generación (UB-8902) y ácido clavulánico

    OpenAIRE

    López Rojas, Rafael

    2011-01-01

    Acinetobacter baumannii se ha convertido en un paradigma de microorganismo nosocomial emergente, debido a la importancia e implicación en situaciones de endemia y brotes nosocomiales de infección. La difusión y extensión de la epidemia de infecciones nosocomiales por A. baumannii se debe principalmente a cuatro factores claves, dos inherentes a la especie que la convierten en única para perpetuarse y diseminarse en el medio hospitalario, y dos derivados de la práctica médica y características...

  13. 噬菌体对鲍曼不动杆菌所致小鼠肠源性脓毒症的治疗效果%Bacteriophage therapy for gut-derived sepsis caused by Acinetobacter baumannii in mice

    Institute of Scientific and Technical Information of China (English)

    李菁华; 余静丹; 史红艳; 王丹; 逯茵茵; 张哲; 孙延波

    2014-01-01

    目的 观察噬菌体对鲍曼不动杆菌引起的小鼠肠源性脓毒症的治疗效果.方法 采用双层琼脂法从环境中分离鲍曼不动杆菌噬菌体.通过腹腔注射氨苄青霉素和环磷酰胺的方法,同时经口感染耐氨苄青霉素鲍曼不动杆菌,建立小鼠肠源性脓毒症模型.在细菌感染前1d、感染结束后2d,以及感染结束后6d给予噬菌体治疗,观察小鼠的存活情况.另取未给予噬菌体治疗小鼠作为对照.各组分别设6只小鼠.采用成组设计的两样本均数t检验比较噬菌体治疗组和对照组小鼠外周血和肝脏内炎症因子水平,以及肝脏和脾脏内的细菌数量.结果 鲍曼不动杆菌引起肠源性脓毒症小鼠全部死亡的最小致死量为1×107 CFU/mL.在感染前、结束后2d和6 d给予噬菌体治疗,分别有2,4,3只小鼠存活,对照组全部死亡.噬菌体治疗组小鼠外周血白细胞介素(IL)-1β、肿瘤坏子因子(TNF)-α和IL-6水平分别为(105±6) ng/L,(105±11)ng/L和(104±12) ng/L,明显低于对照组(t=5.04,9.05和9.33,P<0.01);噬菌体治疗组小鼠肝脏内的IL-1 β和TNF-α水平分别为(104 ±9) ng/L和(104±11)ng/L,亦低于对照组(t=13.70和12.80,P<0.01),但IL-6水平治疗组与对照组比较差异无统计学意义(t=1.06,P>0.05);噬菌体治疗组小鼠肝脏和脾脏内细菌数量分别为(2.9±1.3)×103CFU/g和(8.3±7.6)×102 CFU/g,明显低于对照组(=9.16和8.96,P<0.01).结论 噬菌体治疗鲍曼不动杆菌引起的肠源性脓毒症确切有效.%Objective To evaluate bacteriophage therapy for gut-derived sepsis caused by Acinetobacter baumannii in mice.Methods Lyric phages of Acinetobacter baumannii were isolated from environment by using double-layer agar method.A murine model of gut-derived sepsis was established by oral administration of ampicillin-resistant Acinetobacter baumannii and injection of ampicillin and cyclophosphamide into peritoneal cavities of mice.Bacteriophage therapy were

  14. Immunological evaluation of OMV(PagL)+Bap(1-487aa) and AbOmpA(8-346aa)+Bap(1-487aa) as vaccine candidates against Acinetobacter baumannii sepsis infection.

    Science.gov (United States)

    Badmasti, Farzad; Ajdary, Soheila; Bouzari, Saeid; Fooladi, Abbas Ali Imani; Shahcheraghi, Fereshteh; Siadat, Seyed Davar

    2015-10-01

    Acinetobacter baumannii is an important nosocomial pathogen that causes a high morbidity and mortality rate in infected patients with sepsis form. The surface exposed virulence proteins and serum resistance factors helping to dissemination of this bacterium to bloodstream are the most promising vaccine candidates against this microorganism. In this project we immunologically evaluated OMV(PagL)+Bap(1-487aa) and AbOmpA (8-346aa)+Bap(1-487aa) as combination forms as well as Bap(1-487aa), AbOmpA(8-346aa) and OMV(PagL) singly, with addition of alum adjuvant as vaccine candidates. The titers of total IgG, IgG1 and IgG2c as well as concentration of IL-4 and IFN-γ and survival rates were measured in a C57BL/6 murine model with disseminated sepsis. The ratio of IgG1/IgG2c and profile of IL-4/IFN-γ in OMV (PagL)+Bap (1-487aa) formulation shows the humoral and cellular immune responses have been induced robustly and have created a full protection against A. baumannii ATCC 19606 and MDR AB-44 strains. We found that the two combination vaccine candidates were protective and induced both Th1 and Th2 responses.

  15. 鲍氏不动杆菌的生物膜形成能力及相关特征分析%Biofilm formation of Acinetobacter baumannii and its clinical characteristics

    Institute of Scientific and Technical Information of China (English)

    周昭彦; 胡必杰; 郑雷彪; 谢红梅; 高晓东

    2014-01-01

    OBJECTIVE To compare the biofilm formation of Acinetobacter baumannii isolated from patients and en-vironment and analyze the epidemiological and clinical characteristics of the patients with A .baumannii infection or colonization so as to explore the role of biofilm in the A .baumannii infection or colonication .METHODS Totally 110 strains of A .baumannii isolated from the submitted specimens of the ICU hospitalized patients from Jul 2011 to Jun 2012 and 61 strains of A .baumannii isolated from the environment of surgical ICU in Jul 2012 were collect-ed ,then the biofilm formations of those isolates were tested by means of crystal violet quantitative method ,the chi-square test was performed with the use of SPSS19 .0 software ,and the ability of biofilm formation was com-pared between the A .baumannii strains isolated from the ICU patients and those from the environment .RESULTS Of the 110 strains of A .baumannii isolated from the patients ,73 strains could form the biofilm ,accounting for 66 .4% ;of the 61 strains of A .baumannii isolated from the environment ,24 strains could form the biofilm ,ac-counting for 39 .3% .The positive rates of biofilm formation of the A .baumannii strains isolated from the urine , blood ,or catheter specimens were relatively high ,which were 100 .0% ,87 .5% ,and 75 .0% ,respectively .The positive rate of biofilm formation of the A .baumannii strains isolated from the patients who underwent the ventila-tor catheter indwelling was 78 .3% ,significantly higher than 54 .3% of those isolated from the patients who did not undergo the ventilator catheter indwelling , and there was statistically significant difference ( P< 0 .05 ) . CONCLUSION The ability of biofilm formation of the clinical isolates of A .baumannii is significantly higher than that of the isolates from the environment ,which indicates that the A .baumannii strains with formed biofilm are more likely to cause the colonization or infections in human beings and that the

  16. Analysis on Infection Distribution and Drug Resistance of 116 Strains of Acinetobacter Baumannii%116株鲍曼不动杆菌的感染分布及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    林胜兰; 李静; 王龙飞

    2011-01-01

    Objective To investigate the clinical distribution and drug resistance of 116 strains of Acinetobacter baumanii in our hospital and to offer reference for clinical therapeutics.Methods The infection distribution and the susceptibility results of 116 strains of Acinetobacter Baumanii were analyzed retrospectively from hospitalized patients during Feb.2009 to Feb.2010 and identified by VITEK-32 System of drug susceptibility.The results were assessed with NCCLS.Results The highest appearing rate of Acinetobacter baumannii strains was in sputum (86.10% ), the second was in the wound secretion.ICU ward showed the highest proportion of Acinetobacter baumanii, followed by the departments of neurosurgery and respiration.In the results of the sensitivity to antibiotics, Acinetobacter baumannii strains had the highest drug resistance rate to cefoxitin(95.60% ), the lowest resistance rate to imipenem(3.60% ).The drug resistance rates to ticarcillin clavulanic, cefoperazone sulbactam, amoxicillin clavulanate were 23.60%, 32.40% and 34.70% respectively, which also had high resistant to other 14 kinds of tested antibiotics.Moreover these strains showed multi- drug resistance.Conclusion Acinetobacter baumanii mainly causes lower respiratory tract infection.The sensitivity drugs are few.Imipenem is the primary choose to treat the infections caused by Acinetobacter baumannii.It is important to enhance the surveillance of Acinetobacter baumannii, select rational antibiotic drugs correctly according to the results of antibiotics susceptibility tests to improve drug action,delay the occurrence of bacteria resistance and control the infection effectively.%目的 调查南充市中心医院116株鲍曼不动杆菌的感染分布与耐药情况,为医院临床诊治提供参考.方法 对2009年2月至2010年2月住院患者送检标本分离的116株鲍曼不动杆菌的感染分布与耐药情况进行回顾性分析,采用法国生物梅里埃公司生产的VITEK-32全自

  17. Infection of Acinetobacter baumannii in lower respiratory tract and the variations of drug resistance%下呼吸道鲍曼不动杆菌感染及耐药性变迁

    Institute of Scientific and Technical Information of China (English)

    蓝柳燕; 王君; 辜红妮; 林漫燕; 陈曼丹

    2010-01-01

    目的 观察下呼吸道鲍曼不动杆菌感染及耐药性变化的趋势.方法 回顾性调查分析2005年1月至2008年12月本院分离自住院患者痰样本的鲍曼不动杆菌及其耐药性资料.结果在4年的痰检测样本中,共分离到鲍曼不动杆菌234株,占总体痰样本细菌检出率的8.5%.所有菌株均引起下呼吸道感染,对亚胺培南、美罗培南耐药率最低,分别为4%~9%和5%~6%,对其他抗生素均有较高的耐药率.结论 鲍曼不动杆菌感染以临床危重病患者(ICU、脑外科、烧伤科、呼吸内科)多见.大部分药物的鲍曼不动杆芮耐药率逐年上升.临床跃务人员应加强监测,并根据病原菌培养药敏结果选用敏感抗生素,规范抗生素应用,保持敏感抗生素的抗菌活性,以提高疗效和减缓耐药株的产生.%Objective To investigate the infection of Acinetobacter baumannii in lower respiratory tract and the variations of trendency of drug resistance.Methods The data concerning Acinetobacter baumannii infection in our hospi-tal from January 2005 to December 2008 were retrospectively analyzed.Results Of all the sputum samples in 4 years,234 strains of Acinetobacter baumannii were isolated and the detectable rate was 8.5 %.All the strains caused lower res-piratory tract infection.The drug-resistance rate of imipenem(4%~9%)and meropenem(5%~6%)was the lowest among most of antibiotics,other antibiotics showed higher drug-resistance rate.Condusions The infections of Acineto-batter baumannii mainly happen in critical patients and most of the patients are in ICU,aural sursery departement,burns surgery department,respiratory medicine depariment.The drug-resistance rate of antibiotics shows an increasing trendency in recent years.Clinical staff should strengthen antibiotic resistance monitoring,choose antibiotics on the drug-sensitive results,standardize the drug use and improve the curative effect.

  18. 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

  19. 儿童重症监护病房多重耐药鲍氏不动杆菌肺部感染危险因素及耐药性分析%Risk factors and antibiotic resistance analysis of pneumonia caused by multidrug resistant acinetobacter baumannii in pediatric intensive care unit

    Institute of Scientific and Technical Information of China (English)

    蔡小芳; 孙继民; 鲍连生; 李文斌

    2012-01-01

    Objective To investigate the risk factors involved in the refractory pneumonia caused by multidrug resistant acinetobacter baumannii (MDRAb) in pediatric Intensive care unit (PICU).Methods From January 2009 to August 2011,115 patients with MDRAb pneumonia were treated in Department of Emergency,Wuhan Children's Hospital,Wuhan.Another 45 patients with negative MDRAb (NMDRAb)pneumonia served as control.The patients in the two goups were analyzed using univariate and multivariate Logistic regression to find out the risk factors for MDRAb infection.Results Among the 176 clinical strains of acinetobacter baumannii isolated,128 (72.73%) strains were MDRAb.After drug susceptibility tests,acinetobacter baumannii showed the rates of resistance to β-lactams antibiotics not including cefoperazone-sulbactam were more than 70%,and the rates of resistance to carbapenems antibiotics were higher than 90%.All rates of resistance to antibiotics of betalactams and carbapenems in MDRAb were higher than those in NMDRAb significantly.There were very low rates of drug-resistance found in Amikacin,Levofloxacin,Ciprofloxacin and Minocycline ( <20% ).Multivariate logistic regression revealed that ICU stay,length of time for mechanical ventilation,anemia,hypoproteinemia and the use of carbapenems were independent risk factors involved in MDRAb pneumonia.Conclusions MDRAb was an important conditional pathogen with high rate of drug-resistance to many antibiotics leading to pneumonia in PICU.It increased the mortality of patients significantly.To control the infection of MDRAb was the key to increasing efficacy of treatment of pneumonia in PCIU.%目的 调查儿童重症监护病房(PICU)多重耐药鲍氏不动杆菌(MDRAb)肺部感染危险因素及药物敏感性,为减少MDRAb感染发生及有效治疗提供帮助.方法 以45例非MDRAb肺部感染患儿(NMDRAb组)为对照,回顾性分析2009年1月至2011年8月武汉市儿童医院PICU收治的115例MDRAb肺部感染(MDRAb

  20. 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.

  1. 鲍曼不动杆菌血流感染临床特征和死亡危险因素分析%Analysis of clinical manifestations and risk factors of mortality in Acinetobacter baumannii bloodstream infection

    Institute of Scientific and Technical Information of China (English)

    张银维; 周华; 蔡洪流; 杨青; 沈茜; 沈毅弘; 周建英

    2016-01-01

    Objective To explore the clinical manifestations,antimicrobial therapy,and risk factors of mortality in patients with Acinetobacter baumannii bloodstream infection.Methods Clinical data of 153 patients with Acinetobacter baumannii bloodstream infection hospitalized in First Affiliated Hospital of Zhejiang University from January 2013 to September 2014 were analyzed retrospectively.According to the 28-day survival after diagnosis,the patients were divided into death group (n =76) and survival group (n =77).Data related to demographic and clinical characteristics,underlying diseases,treatment,invasive procedures,bacterial resistance to antibiotics,acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ)scores at onset,and antimicrobial therapy were collected.The index as an independent risk factor of mortality was demonstrated by multivariate logistic regression analysis.Results This study included 153 patients with Acinetobacter baumannii bloodstream infection.The 28-day mortality was 49.7%.The independent risk factors of mortality were APACHE Ⅱ score ≥22 at onset (OR =15.7,95% CI 5.1-48.1,P < 0.001),septic shock (OR =6.3,95 % CI 1.9-21.3,P =0.003),and administration of steroids (OR =3.6,95% CI 1.0-12.3,P =0.043).Compared with subjects treated with non-cefoperazone-sulbactam-based regimen,those treated with cefoperazone-sulbactam for multidrug-resistant Acinetobacter baumannii (MDR-AB) had significantly lower mortality on day7,day14 and day28 (8.9% vs 59.2%,31.1% vs 65.8%,44.4% vs 72.4% respectively).Conclusions The patients with Acinetobacter baumannii bloodstream infection have high mortality within one month.Administration of steroids and septic shock are associated with poor prognosis.APACHE Ⅱ score ≥ 22 at onset predicts adverse outcome.Cefoperazone-sulbactam-based antimicrobial therapy improves patients' survival.%目的 探讨鲍曼不动杆菌血流感染患者的临床特征、抗菌药物治疗

  2. Isolation and antimicrobial resistance of imipenem/cilastatin-resistant Acinetobacter baumannii%耐亚胺培南/西司他丁鲍曼不动杆菌的分离及耐药性

    Institute of Scientific and Technical Information of China (English)

    欧阳育琪; 史文元; 黄红卫; 林应标; 黄强; 熊劲芝

    2011-01-01

    Objective To study the isolation and antimicrobial resistance of imipenem/cilastatin (IPM)-resistant Acinetobacter baumannii (A. Baumannii) in a hospital. Methods Clinical specimens were collected from January 2006 to December 2010, except the blood culture was performed with United States BD BACTEC9120 system, the other specimens were cultured and isolated bacteria with routine method ; strains were identified and performed drug sensitive test with Phoenix 100 automatic analysis system and reagents. The metallo-j3-lactamases were detected with 2-mercaptopropanoic acid inhibited assays. Results One hundred and fifty-four (74. 03%) IPM-resistant A. Baumannii strains were mainly isolated from sputum and throat swabs, strains mainly distributed in the following departments: intensive care unit (98 isolates,63. 64%),. Department of neurology (25,16. 23%), burn unit (13, 8.44%), respiratory department(8, 5. 19%), geriatrics department (4, 2. 60%), department of general surgery (3,1. 95%), and hematological department(3,1. 95%) . IPM-resistant A. Baumannii had the lowest resistant rate to cefoperazone/sulbactam (42. 21%), and the resistant rates to the other antimicrobial agents were all >65 %. The rate of metallo-fMactamase-producing strains was 14. 94%(23/154). Conclusion The IPM-resistant A. Baumannii are chiefly from specimens in respiratory tract infection, and the susceptibility to antimicrobial agents is low. The strengthening of the monitor and optimization use of antimicrobial agents is important for controlling the prevalence of IPM-resistant A. Baumannii in hospitals.%目的 了解耐亚胺培南/西司他丁(IPM)鲍曼不动杆菌(Ab)在某院的分离及其耐药性.方法 收集该院2006年1月-2010年12月临床各类标本,除血培养采用美国BD公司BACTEC9120进行检测,其余标本按常规方法培养分离细菌;在Phoenix 100全自动分析系统和配套试剂中,对菌株进行鉴定及药敏试验.采用2-巯基丙酸抑

  3. 替加环素治疗耐碳青霉烯鲍曼不动杆菌感染的临床疗效%Clinical efficacy of tigecycline in the treatment of infection with carbapenem-resistant Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    张鹏; 李淑芸; 杜云波; 李超梁; 陈炎堂

    2016-01-01

    Objective To evaluate clinical efficacy of tigecycline alone or in combination with other antimicrobials in treating infection caused by carbapenem-resistant Acinetobacter baumannii (CRAB).Methods Patients with hos-pital-acquired pneumonia (HAP)and/or bloodstream infection in the intensive care unit of a hospital between Janu-ary 2013 and June 2014 were selected,efficacy of tigecycline treatment was analyzed.Results Of 25 patients with CRAB infection,21 were with HAP,2 with bloodstream infection,and 2 with both HAP and bloodstream infec-tion.13 cases were multidrug-resistant Acinetobacter baumannii (MDRAB), 10 cases were extensively drug-resistant Acinetobacter baumannii (XDRAB).The susceptibility rate of 25 CRAB isolates to tigecycline was 84%. After treated with tigecycline,white blood cell count(WBC),C-reactive protein (CRP),and procalcitonin (PCT) all significantly decreased (all P<0.01).The clinical effective rate,bacterial clearance rate,and 30-day mortality were 68.00% (17/25),66.67%(14/21),and 28.00% (7/25)respectively;effective rate of 21 cases of HAP was 76.19% (16/21),1 case of bloodstream infection was effective,2 cases of HAP combined bloodstream infection died.Conclusion Tigecycline is effective in the treatment of HAP caused by CRAB,but the therapeutic effect on bloodstream remains uncertain,further research is needed.%目的:了解替加环素单药或联合用药治疗耐碳青霉烯鲍曼不动杆菌(CRAB)感染的临床疗效。方法选择某院重症监护病房(ICU)2013年1月—2014年6月 CRAB 医院获得性肺炎(HAP)和血流感染者,分析替加环素的治疗效果。结果25例患者,其中肺部感染21例,血流感染、肺部感染合并血流感染各2例。其中13例为多重耐药鲍曼不动杆菌(MDRAB),10例为泛耐药鲍曼不动杆菌(XDRAB)。25株 CRAB 对替加环素的敏感率为84%。使用替加环素后患者白细胞计数、C 反应蛋白(CRP)和降钙素原(PCT)

  4. 碳青霉烯类耐药鲍曼不动杆菌分子流行病学及耐药机制的研究%Molecular epidemiology and drug resistant mechanisms of carbapenem-resistant Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    张晓兵; 刘星; 龚雅利; 府伟灵

    2011-01-01

    Objective To investigate the molecular epidemiology and drug resistance mechanism of carbapenem-resistant Acinetobacter baumannii (CRAB). Methods Antimicrobial susceptibility was tested on 51 strains of Acinetobacter baumannii isolated in our hospital from January to December 2008 by Kirby-Bauer method. The results were assessed according to the standards recommended by CLSI (2008). The homology of 51 isolates of CRAB was determined by randomly amplified polymorphism DNA (RAPD). The genotype of TEM, SHV, CTX-M, IMP-1, IMP-2, VIM, VIM-2, OXA-23, OXA-24 and class Ⅰ , Ⅱ integrase (Iht-1 and Int-2) was detected by polymerase chain reaction (PCR). Results These 51 strains Acinetobacter baumannii were all multi-drug resistant, and were resistant to most antibiotics except amikacin. Among them, 50 strains were the same clone. Positive rate of these strains to TEM, SHV, CTX-M, IMP-1, VIM-2, OXA-23 and Int1 was 98.0%, 23.5%, 19.6%, 25.5%, 19.6%, 72.5%, and 86.3%, respectively. But no genotype of IMP-2, VIM, OXA-24 and Iht-2 was detected. Conclusion The stain of CRAB with TEM, OXA-23, IMP-1, VIM-2 and Int-2 genotypes breaks out in our hospital. Its production of OXA-23 carbapenemase and metallo β-Iactamase might be the main mechanisms of carbapenem resistance .%目的 分析我院碳青霉烯类耐药的鲍曼不动杆菌分子流行病学及耐药机制.方法 鲍曼不动杆菌源自2008年1-12月我院临床分离株,共51株.采用K-B法(CLSI 2008年标准)筛选对碳青霉烯类耐药的鲍曼不动杆菌临床分离株,采用随机引物多态性DNA(randomly amplified polymorphism DNA,RAPD)分型对其进行分子流行病学研究;PCR方法检测TEM、SHV、CTX-M、IMP-1、IMP-2、VIM、VIM-2、OXA-23、OXA-24等耐药基因型以及Ⅰ、Ⅱ类整合酶.结果 51株碳青霉烯类耐药鲍曼不动杆菌为多重耐药菌株,除阿米卡星外,其他抗生素耐药率数据非常高;其中50株为同一克隆株;TEM、SHV、CTX-M、IMP-1、VIM-2

  5. Imipenem-resistant Acinetobacter baumannii carrying the ISAba1-bla OXA-23, 51 and ISAba1-bla ADC-7 genes in Monteria, Colombia

    Directory of Open Access Journals (Sweden)

    Pedro Martínez

    2012-12-01

    Full Text Available The purpose of this study was to identify the genes coding for resistance to ceftazidime and imipenem and describe the molecular epidemiology of A. baumannii strains isolated from a clinical center in Colombia. Twenty isolates of imipenem-resistant A. baumannii from an equal number of patients with nosocomial infections were obtained. Primers were used to amplify genes bla IMP, bla VIM, bla OXA-23, bla OXA-24, bla OXA-58, bla OXA-51 and bla ADC-7. To detect insertion sequences ISAba1/bla OXA-23, ISAba1/bla OXA-51 and ISAba1/bla ADC-7, mapping by PCR using combinations of reverse primers ISAba1 and reverse primers of bla OXA-23, bla OXA-51 and bla ADC-7 were used. The amplification products were purified and cloned into PCR 2.1-TOPO vector and transformed into chemically competent Escherichia coli TOP10. These amplicons were then sequenced. PFGE was performed on DNA of A. baumannii isolates digested with ApaI. Results. The DNA profiles obtained included 9 clusters with, four 2-7 isolates per profile, and 5 single-isolate profiles. Of the 20 isolates resistant to imipenem, 15 carried bla OXA-23 gene, 4 contained ISAba1 upstream of bla OXA-51 gene, and 6 contained ISAba1 upstream of bla OXA-23 gene. Eighteen of these isolates carried the bla ADC-7 gene, with 9 of the isolates having ISAba1 located upstream of this gene. This is the first report of the ISAba1 /ADC-7 associated with OXAs genes in A. baumannii isolates from Colombia.

  6. Preliminary study of the relationship between drug sensitivity and molecular typing of of acinetobacter baumannii%鲍曼不动杆菌耐药性与分子分型相关性研究

    Institute of Scientific and Technical Information of China (English)

    尤涛; 辛那; 井发红; 康炜

    2012-01-01

    目的 初步研究11株鲍曼不动杆菌临床分离株药敏试验结果与脉冲场电泳分子分型结果之间的相关性.方法 利用常规方法对从临床标本中分离的鲍曼不动杆菌进行培养鉴定后进行药敏实验,利用脉冲场电泳方法进行分子分型,并比较二者结果.结果 4株对所有抗菌药物均敏感的菌株带型数为10~13条,而1株对所有抗菌药物全耐药为19条带型,其余6株带型在二者之间.结论 分子分型结果初步可以显示耐药情况,相同的分子分型菌株药敏试验结果一致性较高.%Objective To study the; correlation between the antimicrobial susceptibility and pulsed-field gel electrophoresis molecular classification of 11 strains of acinetobacter baumannii .Methods 11 strains of acinetobacter baumannii were isolated from clinical samples .Conventional methods were used for culturing and drug sensitivity testing .Pulsed-field gel electrophoresis method was performed for molecular typing .The two results were compared by using statistical methods .Results 4 strains that sensitive to all antibiotics had 10-13 electrophoresis strips,and 1 strain that resistance to all antibiotics had 19 electrophoresis strips .The rest strains were with electrophoresis strip between the two results mentioned above .Conclusion Molecular typing results could pre-liminaryly show drug resistance,and molecular typing of the same results,higher consistency of antibiotic susceptibility .

  7. 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.

  8. Analysis of drug resistance tendency of Acinetobacter baumannii in Meizhou area during 2008-2012%梅州地区2008~2012年鲍曼不动杆菌耐药趋势分析

    Institute of Scientific and Technical Information of China (English)

    肖光文; 汪雪涛; 乔亚峰; 邹尚平; 叶振东

    2014-01-01

    Objective To analyze the detection rate and drug resistance tendency of Acinetobacter (A .) baumannii in Meizhou area during 2008-2012 in order to provide the guidance for clinicians′medication .Methods The detection rate and drug resistant rate of A .baumanii in the clinical specimens submitted from 5 hospitals in Meizhou during 2008 -2012 were retrospectively ana-lyzed .The antimicrobial susceptibility test was performed by the disk diffusion method .The WHONET 5 .4 and SPSS18 .0 soft-wares were adopted to analyze the data .Results The detection rates of A .baumanii in these five years were 12 .91% ,15 .40% , 11 .94% ,13 .59% and 14 .00% respectively .In the sources of strains ,sputum had the highest distribution rate of 68 .99% (1 713/2 483) ,in the distribution of departments ,ICU had the highest distribution rate of 33 .91% (842/2 483) .The resistance rate of A . baumannii to cefoperazone/shubatam ,meropenem and imipenem were below 30% in the five years ,but showed the upward tenden-cy .The 5-year total drug resistance rates of A .baumanii to 18 kinds of antibacterial drugs were statistically different between ICU and non-ICU department (P<0 .05) ,the drug resistant rate of isolates from ICU was higher than that from the non-ICU depart-ments .The isolation rate of multi-drug resistant strains of A .baumanii was fluctuated in about 50% during these five years except the lower isolation rate in 2008 ,the isolation rate of pan-drug resistant A .baumanii and carbapenem resistance A .baumanii showed the upward tendency .Conclusion The drug resistance rate of A .baumanii is gradually increased .The drug resistance monitoring of A .baumanii in ICU should be strengthened .Antimicrobial agents should be reasonably used for maximizing to retard the emergence of drug resistant strains .%目的:分析梅州地区2008~2012年鲍曼不动杆菌(ABA )的检出及耐药趋势,为临床医师用药提供指导。方法回顾性分析梅州5家医院2008~2012年

  9. 鲍曼不动杆菌血流感染预后的危险因素分析%Analysis of risk factors on prognosis of Acinetobacter baumannii bloodstream infection

    Institute of Scientific and Technical Information of China (English)

    乔莉; 张劲松; 梅亚宁; 张华忠; 苏成磊

    2013-01-01

    Objective To explore the risk factors on prognosis of Acinetobacter baumannii bloodstream infection.Methods Clinical data from 78 patients with Acinetobacter baumannii bloodstream infection hospitalized in First Affiliated Hospital of Nanjing Medical University from January 2010 to November 2012 were analyzed retrospectively.According to the 28-day prognosis after admission,the patients were divided into non-survivors (n=40) and survivors (n=38).Data on demographic and clinical characteristics,wards,underlying diseases,treatments,invasive medical procedures,bacterial resistance to antibiotics,and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score in the beginning were collected.The index as an independent risk factor of mortality was demonstrated by multivariate logistic regression analysis.The predictor value was concluded by comparing area under the receiver operating characteristic curve (ROC curve) of each index.Results Risk factors of mortality of Acinetobacter baumannii bloodstream infection goes as following,including intensive care unit admission [ICU,odds ratio (OR)=12.9,95% confidence interval (95% CI) 2.4-63.5,P=0.001],trachea intubationor tracheostomy (OR =6.2,95% CI 1.5-30.4,P=0.023),invasive mechanical ventilation (OR =5.1,95% CI 1.4-22.6,P=0.042),invasive medical procedure besides central venous catheter (including thoracentesis,bone marrow puncture,lumbar puncture,catheterization,bronchoalveolar lavage with bronchofibroscope,arteriovenous fistula plastic operation,OR =8.4,95%CI 1.7-37.8,P=0.011),APACHE Ⅱ score ≥ 19 in the beginning (OR=35.4,95%CI 3.8-318.6,P=0.001).With respect to APACHE Ⅱ score ≥ 19 as mortality cut-off point,an area under the receiver operating curve of 0.938 was statistically significant (P<0.05),with sensitivity 76.2% and specificity 94.1%.The relationship between prognosis and antibiotic resistance did not have statistically significance.Conclusion Invasive medical procedures and

  10. Structural relationship of the lipid A acyl groups to activation of murine Toll-like receptor 4 by lipopolysaccharides from pathogenic strains of Burkholderia mallei, Acinetobacter baumannii and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Kirill V Korneev

    2015-11-01

    Full Text Available Toll-like receptor 4 (TLR4 is required for activation of innate immunity upon recognition of lipopolysaccharide (LPS of Gram-negative bacteria. The ability of TLR4 to respond to a particular LPS species is important since insufficient activation may not prevent bacterial growth while excessive immune reaction may lead to immunopathology associated with sepsis. Here we investigated the biological activity of LPS from Burkholderia mallei that causes glanders, and from the two well-known opportunistic pathogens Acinetobacter baumannii and Pseudomonas aeruginosa (causative agents of nosocomial infections. For each bacterial strain, R-form LPS preparations were purified by hydrophobic chromatography and the chemical structure of lipid A, an LPS structural component, was elucidated by HR-MALDI-TOF mass spectrometry. The biological activity of LPS samples was evaluated by their ability to induce production of proinflammatory cytokines, such as IL-6 and TNF, by bone marrow-derived macrophages (BMDM. Our results demonstrate direct correlation between the biological activity of LPS from these pathogenic bacteria and the extent of their lipid A acylation.

  11. Structural Relationship of the Lipid A Acyl Groups to Activation of Murine Toll-Like Receptor 4 by Lipopolysaccharides from Pathogenic Strains of Burkholderia mallei, Acinetobacter baumannii, and Pseudomonas aeruginosa

    Science.gov (United States)

    Korneev, Kirill V.; Arbatsky, Nikolay P.; Molinaro, Antonio; Palmigiano, Angelo; Shaikhutdinova, Rima Z.; Shneider, Mikhail M.; Pier, Gerald B.; Kondakova, Anna N.; Sviriaeva, Ekaterina N.; Sturiale, Luisa; Garozzo, Domenico; Kruglov, Andrey A.; Nedospasov, Sergei A.; Drutskaya, Marina S.; Knirel, Yuriy A.; Kuprash, Dmitry V.

    2015-01-01

    Toll-like receptor 4 (TLR4) is required for activation of innate immunity upon recognition of lipopolysaccharide (LPS) of Gram-negative bacteria. The ability of TLR4 to respond to a particular LPS species is important since insufficient activation may not prevent bacterial growth while excessive immune reaction may lead to immunopathology associated with sepsis. Here, we investigated the biological activity of LPS from Burkholderia mallei that causes glanders, and from the two well-known opportunistic pathogens Acinetobacter baumannii and Pseudomonas aeruginosa (causative agents of nosocomial infections). For each bacterial strain, R-form LPS preparations were purified by hydrophobic chromatography and the chemical structure of lipid A, an LPS structural component, was elucidated by HR-MALDI-TOF mass spectrometry. The biological activity of LPS samples was evaluated by their ability to induce production of proinflammatory cytokines, such as IL-6 and TNF, by bone marrow-derived macrophages. Our results demonstrate direct correlation between the biological activity of LPS from these pathogenic bacteria and the extent of their lipid A acylation. PMID:26635809

  12. Risk factors for nosocomial infections due to carbapenem-resistant Acinetobacter baumannii%耐碳青霉烯类鲍氏不动杆菌医院感染风险分析

    Institute of Scientific and Technical Information of China (English)

    孙吉花; 于苏国; 赵爱荣; 姜雪锦; 邱会芬; 陈建伟; 纪冰; 邢敏

    2015-01-01

    OBJECTIVE To identify the risk factors for nosocomial infections caused by carbapenem-resistant Acine-tobacter baumannii (CRAB) so as to provide guidance for the effective prevention and treatment .METHODS By means of case control study ,the clinical data were collected from 37 patients with CRAB nosocomial infections and 30 patients with carbapenem-sensitive Acinetobacter baumannii (CSAB) nosocomial infections who were treated in the hospital from May 2014 to May 2015 .The non-conditional logistic regression model was established to predict the risk for the CRAB nosocomial infections .RESULTS Of 68 strains of A .baumannii causing the nosocomial infec-tions ,38 were CRAB ,accounting for 55 .88% .Among the patients with CRAB nosocomial infections ,48 .64%were from the ICU ,and 43 .24% were from the neurosurgery department ;the patients with lower respiratory tract infections accounted for 71 .05% .The incidence of CRAB nosocomial infections was associated with the ICU stay (OR= 26 .244)and use of carbapenems before the patients had the infections (OR= 9 .488)(P< 0 .05) . CONCLUSION The ICU stay and use of carbapenems before the infections are the independent risk factors for the CRAB nosocomial infections .It is important to intensify the prevention measures of nosocomial infections in the ICU and reasonably use carbapenems so as to prevent the CRAB .%目的 识别耐碳青霉烯类鲍氏不动杆菌(CRAB)医院感染的风险关键控制点 ,为有效预防控制及治疗提供参考依据.方法 采用病例对照研究 ,收集2014年5月-2015年5月CRAB医院感染患者37例以及碳青霉烯类敏感鲍氏不动杆菌(CSAB)医院感染患者30例的临床资料 ,构建非条件 logistic回归模型分析 ,预测CRAB医院感染风险.结果 68株医院感染鲍氏不动杆菌中CRAB 38株占55 .88% ;CRAB感染的科室及感染部位分布均比较集中 ,ICU及神经外科在48 .64% 和43 .24% ,下呼吸道感染占71 .05% ;入住ICU (OR=26 .244)和感染前

  13. 头孢噻肟钠-舒巴坦钠使用量与鲍曼不动杆菌耐药的相关性%Consumption of cefotaxime sodium-sulbactam sodium and resistance rates of Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    邹何慧; 吴常达; 周琴

    2013-01-01

      目的:评估不同使用量的头孢噻肟钠-舒巴坦钠复合制剂与鲍曼不动杆菌耐药的相关性。方法:将经生化分析和药敏鉴定的114株痰培养鲍曼不动杆菌随机分为实验组和对照组。实验组(57株)采用头孢噻肟钠-舒巴坦钠复合制剂抑菌,对照组(57株)采用头孢噻肟钠单方制剂抑菌,依据不同抗菌药平均每天每100床患者用药的频率和同期对鲍曼不动杆菌的耐药率变化,对两组抗菌药物使用量与耐药率进行相关性统计分析。结果:实验组对鲍曼不动杆菌的平均耐药率为42.4%,对照组的耐药率为63.5%。头孢噻肟钠-舒巴坦钠复方制剂与鲍曼不动杆菌对该药耐药率正相关(P=0.0288);头孢噻肟钠单方制剂与鲍曼不动杆菌耐药率也正相关(P=0.0093)。相对于单方制剂用药,复方用药可有效改善耐药菌对抗菌药的敏感性。结论:头孢噻肟钠-舒巴坦钠抗菌药物使用量与鲍曼不动杆菌耐药性存在相关性,且随着抗菌药使用量的增加,细菌的耐药性越大。%Objective: To assess the correlation between consumption of cefotaxime sodium-sulbactam sodium and resistance rates of Acinetobacter baumannii. Methods: 114 strains of Acinetobacter baumanni , confirmed by biochemical analysis and drug susceptibility test, were randomly assigned to experiment group(n=57, cefotaxime sodium-sulbactam sodium were administered ) or control group(n=57, cefotaxime sodium only was administered ). According to antibacterial consumption which defined as daily doses per 100 bed-days and the resistance rate of Acinetobacter baumanni , the correlation was statistically analyzed between the two groups. Results: The average resistance rate against acinetobacter baumanni in the experimental group was 42.4%, the control group was 63.5%.The resistance to consumption of cefotaxime sodium-sulbactam sodium was significantly correlated with resistance to

  14. ICU患者感染泛耐药鲍氏不动杆菌携带OXA酶与AmpC酶的研究%Pan-resistant Acinetobacter baumannii carrying blaOXA and blaAmpC in ICU

    Institute of Scientific and Technical Information of China (English)

    郭宇航; 范学财; 张吉生; 王勇; 曼萨; 王宇超; 张晓丽

    2016-01-01

    目的:了解IC U患者感染泛耐药鲍氏不动杆菌携带碳青霉烯酶基因、头孢菌素酶(A m pC酶)基因,从而分析其耐药机制。方法常规细菌培养方法分离细菌,用VITEK-2全自动微生物鉴定/药敏测试系统进行菌种鉴定及体外敏感测定;采用多重 PCR检测25株鲍氏不动杆菌携带的碳青霉烯酶、AmpC酶相关耐药基因(16 S rRNA 、OXA-23、OXA-24、OXA-51、OXA-58、ADC、DHA、ISAba1),并对耐药基因扩增的阳性产物进行DNA序列分析。结果 ICU患者感染泛耐药鲍氏不动杆菌均携带 OXA-23、OXA-51、ADC基因,21株携带插入序列ISAba1;DNA序列分析结果显示,OXA-23、OXA-51、ADC分别与NCBI的序列同源性均为99.0%。结论产O X A-23型碳青霉烯酶可能是IC U患者感染鲍氏不动杆菌对碳青霉烯酶类抗菌药物耐药的主要原因,且为同一克隆株传播。%OBJECTIVE To investigate carbapenemase related resistant genes OXA and AmpC of pan-resistant Acinetobacter baumannii (PDRAB) in ICU and to further analyze the resistance mechanism .METHODS A .bau-mannii were isolated from specimens of patients by conventional culture method and the V ITEK-II automated mi-crobial system was used for strain identification and in vitro susceptibility test .Multiplex PCR detection method was used to identify 25 A .baumannii strains carrying carbapenemase and AmpC related resistant genes OXA-23 , OXA-24 ,OXA-51 ,OXA-58 ,ADC ,DHA and ISAba1 ,and the positive amplified products of resistant genes were subjected to DNA sequence analysis .RESULTS The selected PDA samples showed all strains carried OXA-51 ,OXA-23 and ADC genes .Out of 23 PDA strains ,21 carried ISAba1 genes .DNA sequence analysis of OXA-23 ,OXA-51 and ADC with the NCBI sequence showed 99% homology .CONCLUSION OXA-23 producing gene which spread by the same clone may be the main cause of resistance of A .baumannii to carbapenem antimicrobial agents .

  15. Outbreak and control of multidrug-resistant Acinetobacter baumannii infections in ICUs%IC U 感染多药耐药鲍氏不动杆菌暴发与控制

    Institute of Scientific and Technical Information of China (English)

    刘向欣; 耿贺梅; 王爱田; 高景利; 李晓岚

    2015-01-01

    OBJECTIVE To investigate the causes of outbreak of multidrug‐resistant Acinetobacter baumannii (MDRAB) infection in intensive care units (ICUs) and put forward the control measures so as to reduce the inci‐dence of the nosocomial infection .METHODS Totally 8 patients with lower respiratory tract infection caused by MDRAB who were treated in the ICUs from Feb 4 ,2013 to Feb 14 ,2013 were enrolled in the study ,then the epi‐demiological survey was conducted ,the hygiene surveillance of ward environment was carried out .A series of measures ,including the strict isolation ,enhancement of hand hygiene ,and disinfection of environment ,were taken to control the outbreak .RESULTS The MDRAB strains were isolated from 8 of 23 patients who were hospi‐talized the ICUs from Feb 4 ,2013 to Feb 14 ,2013 ,with the infection rate of 34 .8% .A total of 19 strains of A .baumannii were isolated and showed the same drug resistance spectrum .The advanced age ,complication of se‐vere underlying disease ,excessive use of antibiotics ,and invasive operation were the predisposing factors for the A .baumannii infection .Both the health care workers'hands and the surfaces of ward objects were detected positive for the A .baumannii strains .CONCLUSION The poor hand hygiene and disinfection of environment are the leading causes of the outbreak of MDRAB infection .Multiple departments should collaborate to facilitate the implementa‐tion of hand hygiene and disinfection of environment so as to control the outbreak and prevalence of the multidrug‐resistant strains .%目的:调查重症监护病房(ICU)多药耐药鲍氏不动杆菌(MDRAB)暴发的原因,提出感染控制措施,以减少该类医院感染的发生。方法对2013年2月4-14日IC U 8例下呼吸道多药耐药鲍氏不动杆菌感染患者进行流行病学调查和病区环境卫生学监测分析;并对患者采取严格隔离、加强手卫生和环境消毒等一系列措

  16. ICU泛耐药鲍氏不动杆菌肺部感染暴发原因及控制%Causes of pulmonary infections by pandrug-resistant Acinetobacter baumannii in ICU and control strategies

    Institute of Scientific and Technical Information of China (English)

    江云兰; 高念霞; 张茎; 童双润

    2012-01-01

    OBJECTIVE To provide the evidence for the prevention and control of the infections caused by pandrug-resistant Acinetobacter baumanii in ICU through the analysis of the causes of A. baumannii infections in ICU. METHODS The epidemiological survey on the A. baumannii causing pulmonary infections in 4 patients was conducted from Jan 29 to Feb 15,2011, the sources of the infections and the transmission routes were sought,and the ways to interfere and control the infections were taken. RESULTS Of the 34 environmental hygiene specimens, 6 (17. 65%) strains were isolated; polymorphic DNA (RAPD) genotyping of 4 strains of pandrug-resistant A. baumanii isolated from 4 patients were randomly amplified, the result showed that the 4 strains were highly homologous; the infections have been controlled through the integrated interventions, the isolation of the patients infected with 4 strains of pandrug-resistant A. baumannii, and the cleaning and disinfection of the objects surface and the medical devices. CONCLUSION The spread between the hospitals, poor hand hygiene of the medical staff, severe contamination of the environment and the medical devices objects are the causes of A. baumannii infections.%目的 分析ICU鲍氏不动杆菌感染暴发的原因与经过,为预防与控制感染提供依据.方法 对ICU2011年1月29日-2月15日陆续发生4例鲍氏不动杆菌肺部感染开展流行病学调查,查找感染源与传播途径,并采取干预措施控制感染.结果 从34份环境卫生学标本中分离出6株鲍氏不动杆菌,检出率为17.65%;对4例患者分离的4株泛耐药鲍氏不动杆菌进行随机扩增多态性DNA(RAPD)基因分型,结果显示,4株具有高度的同源性;采取综合性干预措施,泛耐药鲍氏不动杆菌感染患者集中隔离、加强医务人员手卫生、加强环境物体表面与医疗设备的清洁消毒等,有效控制了感染.结论 医院间传播、医护人员手卫生较差、环境与医疗设备物体表

  17. 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

  18. Comparison of specimens of ICU and the ICU Acinetobacter baumannii distribution and drug resistance analysis%重症监护病房与非重症监护病房鲍曼不动杆菌分布和耐药性比较

    Institute of Scientific and Technical Information of China (English)

    赵建平; 周秀岚

    2014-01-01

    目的:比较ICU与非ICU鲍曼不动杆菌分布和耐药性。方法回顾性对比分析ICU分离出的1079株和非ICU分离出的8413株细菌;细菌鉴定和药敏试验采用VITEK 2 Compact全自动细菌培养鉴定仪。结果 ICU分离鲍曼不动杆菌最多,构成比(29.2%)明显高于非ICU(6.2%)(χ2=625.955,P<0.05);ICU耐亚胺培南鲍曼不动杆菌(IRAB)的检出率(91.7%)明显高于非ICU(43.5%)(χ2=193.541,P<0.05);ICU和非ICU分离细菌的标本均主要来源于痰液,构成比分别为64.0%和32.9%。 ICU和非ICU分离的鲍曼不动杆菌对阿米卡星耐药率较低(20.0%~21.6%),ICU分离的鲍曼不动杆菌对三、四代头孢菌素、酶抑制剂复合药物、碳青霉烯类、喹诺酮类等广谱抗菌药物的耐药率明显高于非 ICU (χ2=146.124、104.409、253.171、195.646、186.580,均P<0.05)。结论多重耐药鲍曼不动杆菌在ICU的检出率高,应加强细菌监测,合理用药,降低细菌的耐药性。%Objective To compare distribution and drug resistance of Acinetobacter baumannii specimen in the intensive care unit(ICU) and the ICU.Methods Retrospective analysis ICU of 1 079 strains isolated and the 8 413 strains of bacteria isolated from ICU , Bacteria identification and drug sensitive test instrument using VITEK 2 Compact automatic bacterial culture identification .Results Most ICU Acinetobacter baumannii separation , form (29.2%) was significantly higher than the ICU (6.2%),the difference was statistically significant (χ2 =625.955, P<0.05).ICU imine resistant Acinetobacter baumannii from south (IRAB)detection rate(91.7%)was significantly higher(43.5%) than the ICU,difference was statistically significant (χ2 =193.541,P<0.05);Specimens of ICU and the ICU isolated bacteria were mainly comes from sputum ,constitute a ratio of 64.0%and 32.9%respectively. ICU and the separation of the

  19. Epidemiología clínica y microbiológica de la infección/colonización por Acinetobacter baumannii en la unidad de cuidados intensivos del Hospital General La Mancha Centro durante los años 2007 /2009

    OpenAIRE

    Huertas Vaquero, María

    2014-01-01

    Acinetobacter baumannii (ABA) es una bacteria oportunista con gran capacidad de diseminación en el ambiente hospitalario y una elevada facilidad para desarrollar resistencia a los antimicrobianos. En este trabajo se ha realizado un estudio observacional analítico retrospectivo de casos y controles, llevado a cabo en la UCI del Hospital La Mancha Centro durante un brote por ABA transcurrido entre febrero de 2008 y abril de 2009. En el periodo de estudio se detectaron 40 casos de pacientes infe...

  20. 碳青霉烯类耐药鲍曼不动杆菌耐药特征及分子流行病学研究%Characteristics of antimicrobial resistance and molecular epidemiology in carbapenem-resistant Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    孙立颖; 黄磊; 徐国宾

    2012-01-01

    目的 调查2009年碳青酶烯类耐药鲍曼不动杆菌(CRAB)的耐药基因及分子流行病学特征.方法 用PCR筛查碳青霉烯类耐药基因OXA -23、OXA -24、OXA-58、IMP、VIM、NDM-1和adeABC型外排泵结构基因adeB,并进行测序分析;用基因外重复回文序列PCR( repetitive extragenic palindromic sequence-based PCR,Rep-PCR)分型技术进行分子流行病学监测.结果 2009年我院66株CRAB中98.5%的菌株OXA -23基因阳性,95.5% adeB基因阳性,两种基因同时阳性的比率为93.9%,未检出其他耐药基因.66株CRAB可分为A~D4个基因型,我院流行的优势克隆株为A型,波及10个病房.这些基因型不同于2004年我院CRAB流行株.结论 2009年CRAB通过产生OXA-23酶和adeABC型外排泵等机制共同介导碳青霉烯类耐药,CRAB克隆株水平传播是造成2009年鲍曼不动杆菌对碳青霉烯类耐药率增加的主要原因.%Objective To investigate the characterizatics of antimicrobial resistance and molecular epidemiology in carbapenem-resistant Acinetobacter baumannii (CRAB) strains isolated in 2009. Methods Carbapenem-resistance genes,including carbapenemase genes OXA-23,OXA-24,OXA-58,IMP,VIM,NDM-l and adeABC efflux pump gene adeB,were screened by polymerase chain reaction (PCR) and sequenced. The molecular epidemiological characteristics of the selected CRAB strains were analyzed by repetitive ex-tragenic palindromic sequence-based PCR (REP-PCR). Results Among the 66 CRAB strains in 2009,65(98.5%) were 0X4-25 positive,63 (95. 5% ) were adeB positive and 62(93. 9% ) were both OXA-23 and adeB positive. No other resistance genes were detectable. REP-PCR typing results showed that the 66 CRAB strains were divided into 4 genotypes; A,B,C and D. Type A was the predominant clone involving the patients from 10 wards. The genotypes were different from those of the epidemic strains isolated in 2004. Conclusion OXA-23 carbapenemase and adeABC efflux pump were involved in the carbapenem

  1. 耐碳青霉烯类鲍曼不动杆菌耐药性及感染危险因素分析%Analysis of drug resistance and risk factors for infection of Carbapenem-resistant Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    廉婕; 蔡博涛; 雷鑫星

    2016-01-01

    目的 探讨耐碳青霉烯类鲍曼不动杆菌(CRAB)耐药现状及其感染的危险因素,为临床合理使用抗生素及防控CRAB提供科学依据.方法 回顾性调查广东医学院附属南山医院(以下简称"我院")2014年1~12月鲍曼不动杆菌(AB)感染的住院患者的临床资料,分为碳青霉烯类抗生素敏感鲍曼不动杆菌(CSAB)组与CRAB组,将其对19种抗菌药物的耐药情况进行统计,并应用SPSS软件分析CRAB医院感染的危险因素.结果 CSAB组对大多数抗菌药物敏感率>90%,而CRAB组对大多数抗菌药物耐药率>90%,两组对米诺环素和替加环素均没有出现耐药菌株;多因素Logistic回归分析表明,入住ICU天数(OR=2.771,95%CI:1.670~4.59)、使用抗菌药物天数(OR=1.076,95%CI:1.021~1.13)、使用呼吸机(OR=4.627,95%CI:1.919~11.15)和使用碳青霉烯类抗生素(OR=2.980,95%CI:1.033~8.59)是我院CRAB感染的独立危险因素.结论 抗菌药物选择性压力和外源性感染途径在CRAB的产生和传播中起到非常重要的作用,加强医院多重耐药菌感染管理,合理使用抗菌药物,对减少CRAB感染具有重要意义.%Objective To investigate drug resistance and risk factors for infection of Carbapenem-resistant Acinetobac-ter baumannii (CRAB), moreover provide scientific basis for rational use of antibiotics in clinic and early prevention-control of CRAB infections. Methods Retrospective statistics were performed for the clinical data of inpatients with Acinetobacter baumannii infection in Nanshan Hospital Affiliated to Guangdong Medical College ("our hospital" for short) from January 2014 to December 2014, patients were divided into CSAB group and CRAB group, and resistance to 19 antimicrobial agents were surveyed, also risk factors of CRAB were analyzed by SPSS. Results The sensitive rates of CSAB to most antimicrobial agents were up to 90%, while the resistant rates of CRAB to those drugs were up to 90%. No resistant isolate of these two groups

  2. PCR-Tag荧光技术在检测鲍曼不动杆菌中的初步应用%Detecting Acinetobacter baumannii by PCR-Tag Fluorescence Technology

    Institute of Scientific and Technical Information of China (English)

    张晓千; 时文化; 史团省; 赵万千

    2013-01-01

    It was important to find a method for analyzing PCR products by automatic analysis station in clinical labs. A total of 208 clinical samples of Acinetobacter baumannii were examined by traditional PCR-agarose gel electrophoresis and PCR-Tag fluorescence, respectively. The results showed that two methods presented similar results in the sensitivity without statistical significance. PCR-Tag method showed low fluorescent background and high signal-to-noise (S/N) ratio. The procedure of PCR-Tag fluorescence seemed less DNA contaminated. The technology had a potential to be used as an instant detection method in clinical labs. It was suitable for the automatic sample analyzers in clinical labs.%建立一种自动化、高通量化的PCR产物鉴定方法并应用于临检实验室.对临床分离后经过生化反应鉴定的208例鲍曼不动杆菌,运用PCR-Tag(尾标)荧光技术进行检测分析,阳性率达到92%,与同等条件下所进行的普通引物PCR方法相比,结果无显著差异(P>0.05).使用PCR-Tag荧光法检测鲍曼不动杆菌,可满足自动化、高通量、高可靠性的现代临床分子检测技术的要求,符合临床分子细菌学快速检测的发展方向.

  3. Risk factors of hospital-acquired pneumonia caused by carbapenem-resistant acinetobacter baumannii%耐碳青霉烯类鲍氏不动杆菌医院获得性肺炎危险因素分析

    Institute of Scientific and Technical Information of China (English)

    王玲; 杨连松; 王清华; 王剑利

    2011-01-01

    目的 探讨耐碳青霉烯类鲍氏不动杆菌(CRAB)医院获得性肺炎的危险因素.方法 采用病例对照研究,收集2005年1月-2010年12月鲍氏不动杆菌(ABA)引起的医院获得性肺炎92例,分为CRAB 医院获得性肺炎组30例和碳青霉烯类敏感鲍氏不动杆菌(CSAB)医院获得性肺炎组62例;采用单因素分析及多因素logistic回归分析.结果 单因素分析发现,APACHEⅡ评分≥16分、气管插管或气管切开、机械通气、分离出ABA前<2周曾应用过亚胺培南或美罗培南、≥2种抗菌药物联合应用与CRAB感染有关;多因素logistic回归分析发现,APACHEⅡ≥16分(OR=4.144,95%Cl 1.346~12.761,P=0.013)及分离出CRAB前<2周曾应用过亚胺培南或美罗培南(OR=3.236,95%Cl 1.128~9.282,P=0.029)是独立危险因素;CRAB组死亡11例,CSAB组死亡19例,2组死亡率差异无统计学意义.结论APACHEⅡ≥16分及分离出CRAB前<2周曾应用过亚胺培南或美罗培南,是CRAB医院获得性肺炎的独立危险因素.%OBJECTIVE To study the risk factors of hospital acquired pneumonia (HAP) caused by carbapenemresistant Acinetobacter baumannii (CRAB).METHODS A retrospective case control study was conducted for the patients who had HAP caused by A.baumannii (ABA) between Jan 2005 and Dec 2010.There were 30 cases of HAP caused by CRAb and 62 cases of HAP caused by CSAB (carbapenem-senstive A.baumannii).Univariate analysis (T test and chi-square test) and multivariate logistic regression were used for statistics analysis.RESULTS Univariate analysis revealed that five factors were associated with the infection caused by CRAB, which were APACHE Ⅱ score ≥ 16, imipenem/meropenem used less than 2 weeks before isolation of CRAB, and combination therapy of antibiotics, invasive mechanical ventilation, endotracheal intubation/tracheotomy.Multivariate logistic regression analysis identified two independent factors, which were APACHEⅡ score ≥16 (OR=4.144) and imipenem

  4. 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.

  5. 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

  6. 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

  7. 665株鲍曼不动杆菌耐药性变化与用药频度相关性分析%Correlation between drug resistance and drug comsuption in 665 strains ofAcinetobacter Baumannii

    Institute of Scientific and Technical Information of China (English)

    金浩; 仇凡; 孙明忠

    2015-01-01

    目的:调查鲍曼不动杆菌的耐药现状,分析抗菌药物用药频度与细菌耐药性的相关性,促进临床更加合理使用抗菌药物。方法:回顾性分析临床分离的665株鲍曼不动杆菌的耐药性,并结合抗菌药物使用频度分析其与鲍曼不动杆菌耐药性的相关性。结果:鲍曼不动杆菌对多种常用抗菌药物的耐药性均较高,且呈现广泛耐药的趋势。对头孢菌素类、碳青霉烯类等药物的耐药率明显上升。鲍曼不动杆菌的耐药率与抗菌药物的使用频度有一定的相关性,对庆大霉素、哌拉西林/他唑巴坦的耐药率与其用药频度呈显著正相关(r=0.87、0.98,P<0.01);对头孢他啶的耐药率与其用药频度呈正相关(r=0.75,P<0.05);对头孢西丁的耐药率与其用药频度呈负相关(r=−0.74,P<0.05);鲍曼不动杆菌对头孢哌酮/舒巴坦的耐药率与氨基糖苷类药物的使用频度呈负相关(r=−0.84, P<0.05);对阿米卡星的耐药率与头孢菌素的使用频度呈显著正相关(r=0.98,P<0.01)。结论:鲍曼不动杆菌对常用抗菌药物的耐药性较为严重,抗菌药物的用药频度和细菌耐药率之间存在一定的相关性。%Objective: hTis study aim to investigated drug resistance toAcinetobacter baumannii, analyze the relationship between antibiotic use and resistance rates.Methods:hTe drug resistance of 665 strains of Acinetobacter Bauman was analyzed retrospectively, the drug consumption was analyzed by using frequency analysis and the relationship between antibiotic use and resistance rates were analyzed by SPSS.Results:Acinetobacter Bauman has a high resistance to a variety of commonly used antimicrobial agents, and there is a tendency of wider range of drug resistance. hTe resistance rates of cephalosporins and carbapenem drug increase signiifcantly. hTere were Pearson signiifcant relationship between use of three antibiotics and resistance inAcinetobacter

  8. Risk factors and prognosis of patients with bloodstream infection due to carbapenem-resistant Acinetobacter baumannii%耐碳青霉烯类鲍曼不动杆菌血流感染患者危险因素及预后

    Institute of Scientific and Technical Information of China (English)

    黄文治; 乔甫; 王妍潼; 尹维佳; 宗志勇

    2015-01-01

    Objective To explore the risk factors and prognosis of hospitalized patients with bloodstream infection due to carbapenem-resistant Acinetobacter baumannii (CRAB).Methods 163 patients with CRAB bloodstream in-fection from 2010 to 2013 were conducted retrospective case-control study,68 patients with bloodstream infection due to carbapenem-susceptible Acinetobacter baumannii (CSAB)during the same period were as control group. Results The independent risk factors for CRAB bloodstream infection were stay in intensive care unit(ICU)(OR, 1 .27[95%CI ,5.55-22.89])and emergency department(OR,3.57 [95%CI ,1 .67 -7.62])before infection.Pa-tients with CRAB bloodstream infection had lower 28-day survival rate than those with CSAB bloodstream infection (66.17% vs 96.95%,χ2 =15.71 ,P <0.001 ).The independent risk factors for influencing prognosis of Acineto-bacter baumannii bloodstream infection were infection of CRAB (HR 95% CI ,3.01 -67.28),blood disease(HR 95%CI ,3.77-25.97),cardiac insufficiency(HR 95%CI ,2.10-20.41),stay in ICU(HR 95%CI ,1 .01 -5.28), and age(HR 95%CI ,1 .01 -1 .04).Conclusion The independent risk factors for CRAB bloodstream infection are stay in ICU and emergency department before infection,CRAB bloodstream infection is risk factor for influencing prognosis of patients.%目的:探讨住院患者血流感染耐碳青霉烯类鲍曼不动杆菌(CRAB)的危险因素及预后。方法采用病例对照研究,回顾性收集某院2010—2013年 CRAB 血流感染患者163例,并以同期68例对碳青霉烯类敏感的鲍曼不动杆菌(CSAB)血流感染患者作为对照,进行危险因素及预后分析。结果 CRAB 血流感染的独立危险因素是感染前入住重症监护病房(ICU)[OR 及 OR95%CI :1.27(5.55~22.89)]及入住过急诊室[OR 及 OR95%CI :3.57(1.67~7.62)]。鲍曼不动杆菌(AB)血流感染患者28 d 生存率 CRAB 为66.17%,而 CSAB 为96.95%, CRAB

  9. 鲍曼不动杆菌的耐药情况及碳青霉烯酶基因检测%Carbapenemase Gene Detection of Acinetobacter baumannii in the Hospital

    Institute of Scientific and Technical Information of China (English)

    王晓红; 范学财; 张吉生; 王勇; 郭宇航; 曼萨; 张晓丽

    2015-01-01

    In order to understand the distribution of Acinetobacter baumannii drug-resistance and carbapenemase in-cluding oxacillinase ( OXA) and metalloenzyme ( MLE) related resistance genes in the affiliated hospitals of Jiamusi University to provide a foundation for reasonable choice of clinical antibiotic medicine.69 A.baumannii strains were collected and screened in the hospital clinical samples identified by VITEK-II full-automatic microbial identification/susceptibility testing machine from September 2013 to December 2014.Multiplex PCR detection method was used to detect carbapenemase related resistant genes 16S rRNA, OXA-23, OXA-24, OXA-51, OXA-58, IMP, VIM and SIM.The positive amplified products were subjected to DNA sequence analysis.The results showed that the resistant rate of 69 strains to IMP and MEM were 36.2% and 37.68%.The resistant gene was obtained as follows: 69 (100%) carrying OXA-51 gene, 32 (46.4%) carrying OXA-23 gene, 17 (24.6%) carrying OXA-24 gene, 5 (6. 8%) carrying OXA-58 genes.Out of 25 carbapenem resistant strains of A.baumannii identified, 22 (88%) carried OXA-23, 1 (4%) carried OXA-58, 10 (40%) carried OXA-24, and 6 (24%) carried both OXA-23 and OXA-24. DNA sequence analysis of OXA-23, OXA-24, OXA-51 and OXA-58 with the NCBI sequence showed 99%homology. Therefore, the OXA-23 gene producer may be responsible for the main reason of A.baumannii carbapenemase antibi-otic resistance.Moreover, there exists regional epidemic of OXA-24 drug resistant gene A.baumannii in the hospital.%了解佳木斯大学附属第一医院鲍曼不动杆菌耐药性及碳青霉烯酶包括苯唑西林酶和金属酶相关耐药基因分布情况,为临床抗菌药物的合理选择提供依据。2013年9月至2014年12月使用VITEK-II全自动微生物鉴定/药敏测试系统筛选出佳木斯大学附属第一医院临床标本鲍曼不动杆菌69株;采用多重PCR方法检测鲍曼不动杆菌携带的碳青霉烯酶相关耐药基因16SrRNA、OXA-23

  10. Detection of Metallo-β-lactamases produced by carbapenem-resistant Acinetobacter baumannii%碳青霉烯耐药鲍曼不动杆菌耐药性分析及金属β-内酰胺酶检测

    Institute of Scientific and Technical Information of China (English)

    汤荣睿; 龚雅利; 张晓兵

    2011-01-01

    Objective To investigate antimicrobial resistance and detection of Metallo-β-Iactamases produced by carbapenem-resistant Acinetobacter baumannii.Methods Antimicrobial susceptibility test was done on 51 strains of Acinetobacter baurnannii isolated by Kirby-Bauer method.Results were assessed according to the standands recommended by CLSI (2008).Metallo-β-lactamases was detected by EDTA inhibition test.The genotype of IMP-1,IMP-2 , VIM, VIM-2 was performed by polymerase chain reaction (PCR).Results 51 strains Acinetobacter baumannii were multi-drug resistant.Sensitive to antibiotics except Amikacin were low.Positive rate of strains of IMP-1 , VIM-2 was 25.5% , 19.6% , respectively.But no IMP-2 , VIM was detected.Conclusion Production of Metallo-β-lactamases in Acinetobacter baumannii is one of the main mechanisms of carbapenems resistance at our hospital.It brings concern that carbapenem-resistant clone was multipleresistant strains.%目的 研究碳青霉烯类耐药的鲍曼不动杆菌耐药性及产金属β-内酰胺酶情况.方法 采用K-B法(CLSI 2008年标准)筛选对碳青霉烯类耐药的鲍曼不动杆菌临床分离株;用乙二胺四乙酸(EDTA)抑制试验测定鲍曼不动杆菌产金属β-内酰胺酶的情况;PCR方法检测IMP-1、IMP-2、VIM、VIM-2金属酶.结果 51株碳青霉烯类耐药鲍曼不动杆菌为多重耐药菌株,除阿米卡星外,其他抗生素的敏感率都很低;IMP-1、VIM-2基因阳性率分别为25.5%、19.6%;IMP-2、VIM基因均为阴性.结论 产生金属β-内酰胺酶是西南医院鲍曼不动杆菌对碳青霉烯类耐药的主要机制之一.碳青霉烯耐药鲍曼不动杆菌是院内感染的多重耐药株,值得关注.

  11. 2009-2014年我院抗菌药物临床应用对鲍曼不动杆菌耐药性变迁的影响%Influence of clinical use of antibiotics on drug resistance of acinetobacter baumannii at our hospital from 2009 to 2014

    Institute of Scientific and Technical Information of China (English)

    蒋陆霞; 贾秀芹; 庞峰; 陈建忠

    2016-01-01

    Objective To explore the influence of the clinical use of antibiotics on the drug resistance of acinetobacter baumannii and to provide a theoretical basis for the rational use of antimicrobial drugs.Methods The annual consumption of antimicrobial agents and the change trend of drug resistance of acinetobacter baumannii in our hospital from 2009 to 2014 were retrospectively analyzed.And the DDDs of antibiotics were calculated.The correlation between the drug resistance of A.baumannii and the DDDs of antibiotics were analyzed by Pearson analysis.Results 2 859 strains of A.baumannii had a trend of multidrug resistance to common antimicrobial agents.The resistance rate of most beta lactam,enzyme inhibitors,aminoglycosides,quinolones,carbapenems,and sulfonamides were over 65.0%.The resistance rate of cefoperazone/sulbactam and minocycline were relatively low,fluctuating between 32.1% and 54.2%.The DDDs of different antimicrobial drugs had different degrees of rises and falls from 2009 to 2014.There was a high positive correlation between the resistance rates of A.baumannii and the DDDs of gentamicin,cefepime,levofloxacin,and imipenem (r>0.800,P<0.05).Conclusions The resistance of acinetobacter baumannii to commonly used antibacterials is relatively serious.The drug resistance of A.baumannii associates with the consumption of antibiotics;and the integrated management of antimicrobial applications should be strengthened.%目的 研究鲍曼不动杆菌耐药性变迁趋势,探讨抗菌药物使用对鲍曼不动杆菌耐药率变化的影响,为临床合理使用抗菌药物提供理论依据.方法 回顾性分析2009-2014年鲍曼不动杆菌耐药率变化趋势及抗菌药物年用量,计算用药频度(DDDs),采用Pearson相关分析法对耐药率与DDDs进行分析.结果 2 859株鲍曼不动杆菌菌株对常用抗菌药物呈多重耐药趋势,对β-内酰胺类、大多β-内酰胺类加酶抑制剂、氨基糖苷类、喹诺酮类、碳青霉烯类

  12. 重症监护病房鲍氏不动杆菌感染监测及干预效果%Monitoring of acinetobacter baumannii infection in ICU and effect of intervention

    Institute of Scientific and Technical Information of China (English)

    周宏; 郑伟; 韩方正; 茅一平; 康海全

    2011-01-01

    目的 分析ICU鲍氏不动杆菌(ABA)感染的特点及耐药性,指导临床合理应用抗菌药物;同时探讨ABA感染的预防控制措施,防止MDRAB暴发流行.方法 分别采用回顾性和前瞻性调查的方法,收集2009年和2010年ICU鲍氏不动杆菌感染的病例资料,分析ABA感染的特点和耐药率;并在2010年开展ICU医院感染目标性监测的同时采取了加强手卫生管理的干预措施,比较干预措施前后2年ABA感染率的差异,以评价干预措施的效果.结果 206例ABA感染的患者共检出ABA 228株,其中MDRAB 162株占71.05%;ABA感染的主要部位为下呼吸道;ABA对常用的5大类17种抗菌药物的耐药率为73.49%~100.00%,对多黏菌素的耐药率较低,为4.52%;手卫生管理等干预措施前后2年ABA感染率差异无统计学意义.结论 ABA带有多种耐药基因,易造成高耐药率和多药耐药,限制广谱抗菌药物在临床的过度使用是防止MDRAB出现的关键;MDRAB存在多种传播途径,必须采取加强手卫生与其他消毒隔离措施并重的综合方法,才能有效地降低其感染率和暴发流行.%OBJECTIVE To analyze the characteristic and drug resistance of Acinetobacter baumannii (ABA) in ICU and help the doctors choose the antifungal agents reasonably; to discuss the control measures of ABA infections and prevent the outbreak of multidrug resistant A. baumannii (MDRAB). METHODS Through retrospective and prospective study, the data of ABA in ICU was collected between 2009 and 2010 and analyzed the characteristic of distribution and drug resistance of ABA. Moreover, in 2010 the targeted surveillance of ICU hospital infections and intervention measures of hand hygiene were carried out, then the results of ABA hospital infections between 2009 and 2010 were compared. RESULTS Totally 206 ABA infection cases were found and 228 plants were detected, in which 162 MDRAB (71.05%) were detected; the most regions of ABA infection were the lower respiratory

  13. 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.

  14. 临床分离鲍曼不动杆菌生物被膜形成能力研究%Biofilm formation ability of clinically isolated acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    邹自英; 朱冰; 熊杰; 曾平; 汪璐; 吴艾霖; 陈莉

    2012-01-01

    Objective To study the biofilm formation ability of clinically isolated strains of acinetobacter baumannii (AB) in order to provide basis for the construction of AB biofilm detection platform and provide evidence for the prevention and control of hospital AB infection. Methods Semiquantitative crystal violet staining was used to detect the biofilm formation ability of AB isolated from clinical specimens. Results ( 1) Among 100 strains of AB, 81 ones had the ability of biofilm formation, in which the ability was weakly positive in 14 ones (17. 28% ) , positive in 21 ones (25. 93% ) and strongly positive in 46 ones (56. 79% ). The biofilm formation ability in other 19 strains was negative. (2) All AB isolated from different specimens had the ability of biofilm formation. (3) There was a negative correlation between the ability of bilfilm formation and drug resistance against antibacterials in vitro. Conclusion AB has strong ability of biofilm formation. Semiquantitative crystal violet staining is simple and convenient, which is a conventional method to detect biofilm formation ability of hospital AB infection.%目的 研究鲍曼不动杆菌(AB)临床分离菌株生物被膜形成能力,为医院感染AB生物被膜检测平台的建立奠定基础,为AB医院感染的预防和控制提供依据.方法 采用半定量结晶紫染色法,检测临床标本分离的AB生物被膜形成能力.结果 (1)100株AB中,81株具有生物被膜形成能力,其中形成能力弱阳性14株(17.28%),阳性21株(25.93%),强阳性46株(56.79%);另19株生物被膜形成检测试验阴性.(2)不同标本来源的AB均具有生物被膜形成能力.(3)AB生物被膜形成能力与体外抗菌药物耐药性呈负相关.结论 AB生物被膜形成能力较强.半定量结晶紫染色法简便易操作,无需特殊设备,可以作为监测医院感染AB生物被膜形成能力的常规方法.

  15. 肿瘤重症患者耐碳青霉烯类鲍氏不动杆菌肺炎危险因素分析%Risk factors for carbapenems-resistant Acinetobacter baumannii pneumonia in severe tumor patients

    Institute of Scientific and Technical Information of China (English)

    汪道峰; 王智; 娄宁

    2012-01-01

    OBJECTIVE To investigate the risk factors of hospital-acquired pneumonia(HAP) caused by carbapen-em-resistant Acinetobacter baumannii (CRAB) in tumor hospital so as to guide the clinical treatment. METHODS By means of retrospective investigation, a total of 269 severe tumor patients were statistically analyzed. RESULTS The incidence rate of CRAB pneumonia was 12. 6%. Multivariate logistic regression analysis showed that the APACHE J[ score more than 16 points ,the use of imipenem/meropenem 15 days before the isolation of CRAB, and the use of bone marrow suppression were the independent risk factors for CRAB, the value of which were 37. 625, 3. 646 and 3. 084, respectively; the mortality due to CRAB pneumonia was 52. 9%. CONCLUSION The effective treatment of the primary diseases, reasonable use of carbapenems and proper use of bone marrow suppression can effectively reduce the incidence of CRAB pneumonia.%目的 分析肿瘤专科医院耐碳青霉烯类鲍氏不动杆菌(CRAB)肺炎高危因素以及预后特点,指导临床治疗.方法 采用回顾性调查方法,对肿瘤专科医院269例重症患者进行统计分析.结果 肿瘤专科医院CRAB肺炎发生率为12.6%,APACHEⅡ评分≥16分、分离出细菌前15d使用亚胺培南、美罗培南、免疫抑制是CRAB肺炎发生的独立危险因素,OR值分别为37.625、3.646及3.084;CRAB肺炎死亡率为52.9%.结论 有效治疗原发病,合理使用碳青霉烯类抗菌药物,纠正骨髓抑制可有效减少肿瘤患者CRAB肺炎发生率.

  16. Genotyping of Carbapenem-resistant Acinetobacter Baumannii Strains Isolated from Intensive Care Units%重症监护室耐碳青酶烯类鲍曼不动杆菌的基因分型

    Institute of Scientific and Technical Information of China (English)

    郑培烝; 邹红; 傅芬蕊; 潘玉红; 黄心宏; 曹颖平

    2014-01-01

    目的:了解笔者医院重症监护室(ICU)分离的耐碳青霉烯类鲍曼不动杆菌(CRAB)的分子流行病学特点。方法收集2010年9月-2012年3月ICU分离的CRAB共34株,其中综合ICU 25株,烧伤ICU 9株,采用基于rep-PCR原理的DiversiLab系统进行基因分型分析。结果34株CRAB共分A、B、C和D 4型,烧伤IC U中存在A和D型,以A型为主且A型仅出现在烧伤IC U ;综合IC U中存在B ,C和D型,以D型为主且B和C型仅出现在综合ICU。结论烧伤ICU和综合ICU 中流行的CRAB基因型不同。D型CRAB同时存在两个IC U中提示IC U间可能存在交叉感染。%Objective To investigate the molecular epidemiology of carbapenem-resistant Acineto-bacter baumannii(CRAB) strains collected from intensive care units (ICUs) in our hospital . Methods 34 CRAB strains were collected and isolated at ICUs of our hospital during the period of September 2010 to April 2012 ,of which 25 from general ICU ,and 9 from Burn ICU . Genotyping was performed by Diversi-lab repetitive element PCR system . Results There were 4 types of CRAB strains ,including type A ,B , C and D . Type A and D CRAB strains existed in Burn ICU Type A dominated . Type B ,C and D CRAB strains were found in general ICU with Type D dominant . Conclusion The epidemic strains of CRAB in Burn ICU was different from that in general ICU ,and the type D CRAB strain appeared simultaneously in both the ICUs suggesting that a cross infection may prevail in the two ICUs .

  17. Sequencing and bioinformatic analysis of genome of Acinetobacter baumannii bacteriophage AB3%鲍曼不动杆菌噬菌体AB3的全基因组测序及生物信息学分析

    Institute of Scientific and Technical Information of China (English)

    张劼; 刘茜; 甘丹

    2013-01-01

    目的 对本研究小组分离的鲍曼不动杆菌噬菌体AB3进行测序和基因组生物信息学分析,阐明其亲缘关系.方法 采用鸟枪法和重叠群组装的策略对噬菌体AB3进行基因组测序,并通过EditSeq、tRNAscan-SE、TRF、FindTerm、ORF finder、BPROM、GeneMarkTM、Clustalx、phylip等软件对所获噬菌体AB3基因组的一般特性、编码基因的功能预测、RNA聚合酶基因系统的进化进行分析.结果 噬菌体AB3基因组为全长31 185 bp的双链DNA,G+C含量为39.18%,包含28个预测基因,1个转录终止子和4个可能的启动子序列.结论 基因分析和RNA聚合酶基因进化分析显示噬菌体AB3与噬菌体AB1类似,均属于phiKMV-like病毒属.%Objective To sequence the Acinetobacter baumannii bacteriophage AB3 separated by our team,and to perform bioinformatics analysis,so as to identify the classification of its phylogenetic relationship.Methods Shot-gun library and config package strategy were carried out for sequencing the genome of bacteriophage AB3.Such software as EditSeq,tRNAscan-SE,TRF,FindTerm,ORF finder,BPROM and GeneMarkTM were applied to predict both general characteristics of the bacteriophage AB3 genome and the coding gene function.In addition,the evolution of RNA polymerase gene system was analyzed with the software of Clustalx and phylip.Results The genome of bacteriophage AB3 was a double-strand DNA with a full length of 31 185 bp,in which G + C mol% was 39.18% and 28 predicted genes,1 transcription terminator,and 4 possible promoter sequences were included.Conclusion Genetic analysis and RNA polymerase gene evolution analysis indicate that bacteriophage AB3 is similar to bacteriophage AB1,and both of them belong to phiKMV-like virus.

  18. Investigation on distribution and antibiotic resistance of Acinetobacter baumannii in Zhoushan city from 2006 to 2010%2006-2010年舟山地区鲍曼不动杆菌感染动态观察

    Institute of Scientific and Technical Information of China (English)

    李海红; 方国安; 陈琼娜; 李春儿; 王晔恺

    2012-01-01

    目的 了解舟山地区近5年鲍曼不动杆菌(Acinetobacter baumanii,Ab)的感染状况及对常见抗菌药物的耐药情况,为有效控制感染和治疗提供依据.方法 对2006年1月至2010年12月临床送检的血、尿及痰等各类标本进行细菌培养、分离与鉴定和药物敏感试验,细菌鉴定采用ATB-expression细菌鉴定仪,药敏试验采用其配套的PSE-5条.结果 2006-2010年共检出鲍曼不动杆菌696株.Ab主要分布于ICU (301,43.4%)和呼吸内科(132,19.0%)的送检标本.痰标本检出率最高,为524株(75.3%).Ab对除妥布霉素以外抗生素的耐药性呈逐年上升的趋势(P<0.01).多重耐药鲍曼不动杆菌比例也逐渐增加.结论 鲍曼不动杆菌对临床常用抗菌药物的耐药性呈逐年上升趋势,多重耐药菌比例明显增加.碳青霉烯类抗生素仍是治疗Ab感染最敏感的药物.应加强鲍曼不动杆菌细菌耐药监测,进一步合理有效使用抗生素,以防止鲍曼不动杆菌的传播,降低多重耐药鲍曼不动杆菌交叉感染的发生.%Objective To investigate the distribution of Acinetobacter baumannii (Ab) and its resistance to antibiotics from 2006 to 2010 in Zhoushan city. Method Clinical specimens during January 2006 and December 2010 were collected for bacteria cultivation, isolation, identification and drug resistance. Result 696 strains of Ab were isolated from 569 specimens, most of which were from the ICU (301, 43.4% ) and department of Respiration (132, 19.0% ). The resistance rate of Ab to imipenem and meropenem showed an increasing trend from 2006 to 2010. Conclusion The resistance rates of Ab to all antibiotics are increasing year by year. More attention should be paid to the rational use of antibiotics

  19. 29株耐亚胺培南和/或美罗培南鲍曼不动杆菌产碳青霉烯酶基因型检测%The genetype of carbapenemase produced by imipenem- and/or meropenem-resistant Acinetobacter baumannii isolates

    Institute of Scientific and Technical Information of China (English)

    魏艳艳; 熊自忠; 邹桂舟

    2012-01-01

    目的 了解临床分离耐亚胺培南和/或耐美罗培南鲍曼不动杆菌中产碳青霉烯酶的基因型别.方法 采用聚合酶链反应扩增IMP、VIM、OXA型碳青霉烯酶基因并测序.结果 29株对碳青霉烯类耐药的鲍曼不动杆菌中,以产OXA-24型和IMP型酶菌株最多,二者均占51.7% (15/29).产OXA-24+ IMP型5株、OXA-24+ OXA-51+IMP型4株、VIM型4株、OXA-24+ OXA-58+ IMP型、OXA-23+ OXA-24+ IMP型各2株,OXA-23+IMP型、OXA-51+OXA-24型、OXA-24型、IMP型各1株,8株细菌PCR检测结果为阴性.结论 耐亚胺培南和/或美罗培南鲍曼不动杆菌主要产OXA-24型和IMP型碳青霉烯酶,部分菌株可同时产2种或以上碳青霉烯酶.%Objective To investigate the genetype of carbapenemase produced by imipenem-resistant and/or meropenem-resistant Acinetobacter baumannii strains clinical isolated. Methods A total of 29 strains of imipenem-resistant and/or meropenem-resistant Acinetobacter baumannii were screened by PCR with primer pairs designed to detect genes encoding OXA-23, 24, 51, 58 and VIM, IMP enzymes, respectively. Results In the 29 carbapenemase producers, OXA-24 and IMP were the most common, each accounting for 51.7% (15/29). The positive strains of OXA-24 + IMP, OXA-24 + OXA-51 + IMP, VIM, OXA-24 + OXA-58 + IMP, OXA-23 + OXA-24 + IMP, OXA-23 + IMP, OXA-51 + OXA-24, OXA-24 and IMP were 5 , 4,4,2,2,1,1,1 and 1 strain, respectively. Conclusion OXA-24 and IMP are the main genotypes of carbapenemase in imipenem-resistant and/or meropenem-resistant Acinetobacter baumannii.

  20. 以替加环素为基础的联合用药治疗多耐药和泛耐药鲍曼不动杆菌感染医院获得性肺炎的临床研究%Efficacy study in tigecycline based combination therapy for multidrug - resistant and pan - resistant Acinetobacter baumannii patient

    Institute of Scientific and Technical Information of China (English)

    赵华; 吴健; 杨爱祥; 陶唯益; 钱进先

    2015-01-01

    Objective To explore the efficacy study in tigecycline based combination therapy for multidrug - resistant and pan - resistant acinetobacter baumannii patient. Methods 68 hospital - acquired pneumonia patients with multi - drug resistant or pan - resistant Acinetobacter baumannii were collected and randomly divided into study group and the control group(34 cases each). In study group,tigecycline joint cefopera-zone / sulbactam treatment was undertaken. The cefoperazone / sulbactam was taken in the control group. Therapeutic effect was compared between the two groups. Results In the study group,clinical efficacy was significantly higher and 28 - day mortality was significantly lower than the con-trol group. Between the two groups,adverse reactions,microbial clearance,ICU length of stay and total hospitalization time had no statistically sig-nificant difference. Conclusion Tigecycline joint cefoperazone/ sulbactam have obvious effect on multidrug - resistant and pan - resistant Acineto-bacter baumannii,which is worthy of clinical application.%目的:探讨以替加环素为基础的联合用药治疗多耐药和泛耐药鲍曼不动杆菌感染医院获得性肺炎的临床疗效。方法选择多重耐药和泛耐药鲍曼不动杆菌的医院获得性肺炎患者共68例,分为研究组和对照组(各34例),前者采用替加环素联合头孢哌酮/舒巴坦治疗,后者则采用头孢哌酮/舒巴坦治疗,比较两组的临床疗效。结果研究组临床有效率显著高于对照组,28天病死率显著低于对照组,差异有统计学意义( P 0.05)。结论替加环素联合头孢哌酮/舒巴坦治疗多重耐药和泛耐药鲍曼不动杆菌感染的感染医院获得性肺炎临床疗效明显,28天病死率低,不良反应少,值得临床应用。

  1. Whole genome and specific genes in epidemic pandrug-resistant Acinetobacter baumannii strains%泛耐药鲍氏不动杆菌流行株全基因组与特定基因分析

    Institute of Scientific and Technical Information of China (English)

    许亚丰; 王春新; 赵琪; 糜祖煌; 翁幸鐾

    2015-01-01

    OBJECTIVE To investigate genetic background of a pandrug‐resistant Acinetobacter baumannii so as to provide guidance for rapid identification of drug‐resistant strains .METHODS The pandrug‐resistant A .baumannii WA2859 was isolated from the sputum specimens of a hospitalized patient in Mar 2010 ,the A .baumannii strain was conformed through the sequencing of gyrA and parC genes as well as comparison of BLASTn ,the whole ge‐nome was analyzed by using two large‐scale parallel sequencers Illumina HiSeq and Ion Torrent PGM ,and PCR was performed to fill gaps .Furthermore ,the specific genes were analyzed (including resistance genes to beta‐lac‐tams and aminoglycosides ,linkage detection of ISaba1‐blaADC and ISaba1‐blaOXA‐23) .RESULTS Complete graph could not be sequenced by whole genome sequencing ,a putative chromosome sequence (2 gaps inside) was 3887116bp ,a putative plasmid sequence (9 gaps inside) was 260513 bp .The specific genes ,including blaTEM , blaADC ,blaOXA‐23 ,aac(6')‐Ⅰb ,ant(3')‐Ⅰ ,and ant(2")‐Ⅰ ,aph(3')‐Ⅰ ,were positive ,and linkage detection was positive for ISaba1‐blaADC and ISaba1‐blaOXA‐23 .CONCLUSION The specific genes are the complement of the whole genome sequencing ,and they are used to perform sample cluster analysis to investigate the phylogenetic relationship among strains and are used to rapidly identify clinical isolates of drug‐resistant strains and study the molecular epidemiology .%目的:调查一株泛耐药鲍氏不动杆菌流行株的遗传学背景,为耐药菌的快速诊断提供参考。方法泛耐药鲍氏不动杆菌WA2859分离自2010年3月住院患者痰液标本,作 gyrA与parC基因测序、BLASTn比对确认为鲍氏不动杆菌,采用Illumina HiSeq与Ion Torrent PGM 两种大规模并行测序仪进行全基因组分析,再进行人工测序补缺口,并进行了特定基因分析(包含β‐内酰胺类、氨基糖苷类抗菌药物获得耐药基因,ISaba1

  2. 泛耐药鲍氏不动杆菌流行株全基因组与特定基因分析%Whole genome and specific genes in epidemic pandrug-resistant Acinetobacter baumannii strains

    Institute of Scientific and Technical Information of China (English)

    许亚丰; 王春新; 赵琪; 糜祖煌; 翁幸鐾

    2015-01-01

    目的:调查一株泛耐药鲍氏不动杆菌流行株的遗传学背景,为耐药菌的快速诊断提供参考。方法泛耐药鲍氏不动杆菌WA2859分离自2010年3月住院患者痰液标本,作 gyrA与parC基因测序、BLASTn比对确认为鲍氏不动杆菌,采用Illumina HiSeq与Ion Torrent PGM 两种大规模并行测序仪进行全基因组分析,再进行人工测序补缺口,并进行了特定基因分析(包含β‐内酰胺类、氨基糖苷类抗菌药物获得耐药基因,ISaba1‐blaADC、ISaba1‐blaOXA‐23连锁检测)。结果泛耐药鲍氏不动杆菌WA2859株全基因组测序未获完整序列,得到一条推定的染色体序列,长3887116 bp(内含两个缺口);推定的质粒序列,长260513 bp(内含9个缺口);特定基因检出blaT EM、blaA DC、blaOX A‐23β‐内酰胺类抗菌药物获得耐药基因和 aac(6′)‐Ⅰ b、ant(3′)‐Ⅰ、ant(2″)‐Ⅰ、ap h (3′)‐Ⅰ氨基糖苷类抗菌药物获得耐药基因,并且 ISaba1‐blaADC、ISaba1‐blaOXA‐23连锁检测均阳性。结论特定基因检测与全基因组测序互为补充,对特定基因检测结果作样本聚类分析并可得到菌株亲缘关系结果,可对临床分离的耐药细菌作快速诊断和分子流行病学研究。%OBJECTIVE To investigate genetic background of a pandrug‐resistant Acinetobacter baumannii so as to provide guidance for rapid identification of drug‐resistant strains .METHODS The pandrug‐resistant A .baumannii WA2859 was isolated from the sputum specimens of a hospitalized patient in Mar 2010 ,the A .baumannii strain was conformed through the sequencing of gyrA and parC genes as well as comparison of BLASTn ,the whole ge‐nome was analyzed by using two large‐scale parallel sequencers Illumina HiSeq and Ion Torrent PGM ,and PCR was performed to fill gaps .Furthermore ,the specific genes were analyzed (including resistance genes to beta‐lac‐tams and

  3. 鲍氏不动杆菌及铜绿假单胞菌肺炎患者死亡相关危险因素分析%Risk factors for mortality of patients with pneumonia caused by Acinetobacter baumannii and Pseudomonas aeruginosa

    Institute of Scientific and Technical Information of China (English)

    王飞; 姚贝; 张捷; 贺蓓

    2013-01-01

    OBJECTIVE To retrospectively investigate the risk factors associated the mortality of the patients with pneumonia caused by Acinetobacter baumannii and Pseudomonas aeruginosa , and focus on the impact of different antimicrobial regimens on the patients with A. baumannii pneumonia so as to guide the clinical treatment. METHODS We searched the qualified respiratory samples (including sputum and endotracheal aspirate) in the hospital during Jan 2012 to Aug 2012, and identified the cases with A. baumannii and/or P. aeruginosa positive isolates. The clinical data of the cases were reviewed and the cases were recruited when they were clinically diagnosed as pneumonia. The clinical and microbiological data of the patients were collected. logistic regression was applied to identify the risk factors of the mortality. RESULTS Totally 79 patients with pneumonia were enrolled in the study, including 46 patients infected with A. baumannii and 33 patients infected with P. aeruginosa; 29 cases died with the mortality of 36. 7%; the multivariate regression analysis showed that the respiratory frequency, blood urea nitrogen, sepsis, albumin level and use of antibiotics were the independent risk factors for the mortality of the patients with A. baumannii or P. aeruginosa pneumonia. The mortality of the patients with A. baumannii pneumonia was 50. 0% , 18. 8% of the patients with P. aeruginosa pneumonia (P = 0. 004) ; A. baumannii infection was an independent factor for the increase in mortality (OR = 4. 33, P = 0. 007). Of all the A. baumannii strains, the multidrug-resistant A. baumannii accounted for 97. 8%; the analysis of treatment program indicated that the use of single carbapenem for the primary treatment may increase the risk of mortality and that the use of other antibiotics had no significant impact on the mortality. CONCLUSION The severity of infection is the independent risk factor for the mortality of the patients with A. baumannii or P. aeruginosa pneumonia. The

  4. 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...

  5. 鲍曼不动杆菌生物膜形成抑制剂实验室初步研究%Biofilm formation and inhibition in Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    聂大平; 马荣; 刘永娥; 李飞

    2011-01-01

    Objective To realize the antimicrobial resistance of Acinetobacter baumannii (Ab), and effect of ethyl-enediaminetetra-5 acetic acid (EDTA ) ,minocycline and salicylic acid on its biofilm formation. Methods Antimicrobial susceptibilities of 72 strains of Ab were detected with Kirby-Bauer method; Minimal inhibitory concentrations of EDTA, minocycline and salicylic acid on Ab were determined by broth microdilution methods The biofilm formation rates of different drug-resistant Ab and the effect of different concentrations of EDTA, minocycline and salicylic acid on biofilm formation and mature biofilm were determined by adhesion test. Results The MIC*, of EDTA, minocycline and salicylic acid for Ab was 200 mg/L,4 mg/L and 600 mg/L, respectively. The biofilm-positive rates in sensitive Ab (Sab) strains, multi-drug resistant (MDRAb) strains and pan-drug resistant (PDRAb) strains was 22. 22%, 83. 33% and 76. 67%, respectively. EDTA with concentration of 250 mg/L and 500 mg/L, minocyline 4 mg/L and 8 mg/L, and salicylic acid 1 000 mg/L can inhibit the mature biofilm. Conclusion There are a high biofilm-positive rate in multi-drug and pan-drug resistant Ab . EDTA, minocycline and salicylic acid can inhibit the formation of biofilm.%目的 了解鲍曼不动杆菌(Ab)耐药性及乙二胺四乙酸(EDTA)、米诺环素和水杨酸对其生物膜形成的影响.方法 采用纸片扩散法测定72株Ab对抗菌药物的敏感性;微量肉汤法测定EDTA、米诺环素和水杨酸对Ab的最低抑菌浓度(MIC);黏附半定量法测定不同耐药性Ab生物膜生成率及不同浓度EDTA、米诺环素和水杨酸对生物膜形成和成熟生物膜的影响.结果 EDTA、米诺环素和水杨酸对Ab 的 MIC90 分别为200 mg/L、4 mg/L和600 mg/L.Ab敏感株、多重耐药株和泛耐药株生物膜形成阳性率分别为22.22%、83.33%和76.67%.250 mg/L和500 mg/L EDTA、4 mg/L和8 mg/L米诺环素以及1000 mg/L水杨酸可抑制成熟生物膜.结论 生物

  6. The resistant characteristic and a part of resistance genes carried of multidrug-resistant Acinetobacter baumannii%多耐药鲍曼不动杆菌耐药性分析和部分耐药基因检测

    Institute of Scientific and Technical Information of China (English)

    张玲玲; 胡俊锋; 李峰; 张永

    2012-01-01

    目的 分析皖北地区多耐药鲍曼不动杆菌(MDR-Ab)耐药率和部分耐药基因携带情况.方法 用稀释法测定抗生素的最低抑菌浓度(MIC),用PCR扩增OXA-51、OXA-23和Ⅰ~Ⅲ类整合子的整合酶基因.结果 MDR-Ab对替加环素、多黏菌素E和利福平体外药敏试验耐药率较低,分别是5.56%、6.94%、16.67%.临床常用16种抗生素中除舒普深(头孢哌酮/舒巴坦)耐药率为41.67%外,其他抗生素耐药率较高.72株MDR-Ab的OXA-51、OXA-23和Ⅰ类整合酶基因的携带率分别为100.00%、84.72%和91.67%,未检出Ⅱ和Ⅲ类整合酶基因.结论 MDR-Ab耐药形势严峻,替加环素、多黏菌素E和利福平是治疗MDR-Ab感染的有效药物.MDR-Ab携带Ⅰ类整合子阳性率较高,OXA-23是导致其对碳青霉烯类抗生素耐药的机制之一.%Objective To analysis the antimicrobial resistance and a part of resistance genes earned of multidmg-resistance Acinetobacter baumannii( MDR-Ab ) in the hospitals of North Anhui. Methods Minimum inhibitory concentrations( MIC )were determined by the borth dilution method. Blaoxa-51-like, blaoxa-23-like genes and integrase genes of intergrons from class 1 to 3 were researched by polymerase chain reaction. Results Tigecycline, colistin and rifampin were effective againist the MDR-Ab, the resistant rates were 5.56%, 6. 94% and 16. 67% , respectively. The lowest rates of 16 kinds currently used antibiotics was cefoperazone-sulbactam ( 41. 67% ). While,others had high resistant rates. Among the 72 strains,all possessed blaoxa-51-like carbapenemase gene,84. 72% ( 61 ) earned blaoxa-23-like carbapenemase gene and 91. 67% ( 66 )with class 1 integrase gene. Conclusions Situation of drug resistance is serious in the clinical separated MDR-Ab. Tigecycline, colistin and rifampin are effective antibiotics to cure MDR-Ab infection. A large number of them are carrying class 1 integrase gene. Blaoxa-23-like gene is the resistant mechanism of permitting the strains

  7. Isolation and biological characteristics of phages of carbapenem-resistant Acinetobacter baumannii%耐碳青霉烯类鲍曼不动杆菌噬菌体的分离鉴定及其生物学特性

    Institute of Scientific and Technical Information of China (English)

    张劼; 罗永艾

    2012-01-01

    Objective To investigate the biological characteristics of phages of carbapenem-resistant Acinetobacter baumannii ( CRAB), and provide new strategy for controlling CRAB infection. Methods Phages of CRAB isolated from raw sewage of a hospital were identified using the plaque method. The morphology of phages was observed by electron microscopy. The genome of phages was extracted for electrophoresis. The structural proteins of phages were analysed by SDS-PAGE. The optimal multiplicity of infection, resistant mutation rate and one-step growth curve of phages were determined. Results One CRAB-specific and tailless phage with double-stranded DNA was isolated, and was named as phage AB3. The size of phage AB3 genome was about 35 kb, and the relative molecular mass of major coat protein was 35 x 10 . The incubation and burst periods of phage AB3 were 20 min and 60 min respectively, the burst size was 350, and the mutation rate of phage resistance was 2.5 × 10-10 . The phage AB3 was stable to a wide range of pH and temperature. Conclusion Phage AB3 has relatively broad host range, shorter incubation period, apparent burst size, lower resistant mutation rate and good stability to physical and chemical factors, which leads to its promising prospect in clinical application.%目的 通过分离耐碳青霉烯类鲍曼小动杆菌(CRAB)噬菌体,研究其生物学特性,为噬菌体治疗CRAB感染提供实验依据.方法 利用噬菌斑法从医院污水中分离CRAB噬菌体,电子显微镜观察噬菌体的形态特征,提取其基因组行酶切电泳,SDSPAGE分析噬菌体表面衣壳蛋白,测定噬菌体感染复数和耐受突变率,并观察其一步生长曲线.结果 筛选出1株具有较宽裂解谱的无尾双链DNA的CRAB噬菌体,命名为噬菌体AB3.其基因组大小约35 kb,表面主要衣壳蛋白相对分子质量约为35×103.该噬菌体感染宿主菌的潜伏期为20 min,爆发期为60 min,裂解量为350,耐受突变率为2.5×10-10,对pH值耐受

  8. Aminoglycoside resistance pattern and genetic background in multi-drug resistant acinetobacter baumannii%多药耐药鲍氏不动杆菌氨基糖苷类药物耐药遗传学背景研究

    Institute of Scientific and Technical Information of China (English)

    陈月馨; 周惠芬; 钟育红; 吴润香; 黄烈; 陈智睿

    2011-01-01

    OBJECTIVE To investigate the background of the Aminoglycoside resistance pattern and genetic type in multidrug-resistant Acinetobacter baumannii (MDR-ABA). METHODS From Apr 2009 to Aug 2009, twenty MDRABA strains were isolated from The Third Affiliated Hospital of Sun Yat-sen University. Drug susceptibility test to 10 kinds of antimicrobial agents was detected by K-B disk diffusion tests. Then, resistant genes and genetic markers were analyzed by PCR and verified by DNA sequencing, including 8 kinds of aminoglycoside modifying enzyme genes(aac(3)- Ⅰ ,aac(3)- Ⅱ ,aac(6′)- Ⅰ ad,aac(6′)- Ⅰ b,aac(6′)- Ⅱ ,ant(3″)- Ⅰ ,ant(2″)- Ⅰ , aph(3′)- Ⅰ ),and 6 kinds of 16S rRNA methylase genes (rmtA, rmtB, rmtC, rmtD, armA, npmA). RESULTS A total of 4 kinds of aminoglycoside modifying enzyme genes of MDR-ABA were detected, including aac(3)-Ⅰ , aac(6′)-Ⅰ b, ant (3″)- Ⅰ , aph(3′)- Ⅰ , and 6 kinds of 16S rRNA methylase genes in twenty MDR-ABA strains were not detected.CONCLUSIONS There is a very high positive rate of aminoglycoside modifying enzyme genes in MDR-ABA isolated from inpatients; The aminoglycosides-resistant MDR-ABA is mainly related to aminoglycoside modifying enzyme genes; The mobile genetic element is the main factor for MDR-ABA to acquire aminoglycoside modifying enzyme genes.%目的 了解临床分离的多药耐药鲍氏不动杆菌(MDR-ABA)氨基糖苷类药物耐药遗传学背景.方法 从2009年4-8月中山大学附属第三医院住院患者中分离20株MDR-ABA,用K-B法测定鲍氏不动杆菌对10种抗菌药物的敏感性,采用PCR及序列分析的方法分析氨基糖苷类修饰酶基因.结果 20株MDR-ABA检出aac(3)-Ⅰ、aac(6′)-Ⅰb、ant(3′)-Ⅰ、aph(3′)-Ⅰ4种基因阳性,6种16S rRNA甲基化酶基因未检出.结论 临床分离的MDR-ABA中氨基糖苷类修饰酶基因阳性率较高,MDR-ABA氨基糖苷类抗菌药物耐药主要与氨基糖苷类修饰酶基因有关;通过可移动遗传元

  9. Combined drug sensitivity test of carbapenem-resistant acinetobacter Baumannii%碳青霉烯耐药鲍曼不动杆菌的联合药敏研究

    Institute of Scientific and Technical Information of China (English)

    夏静静; 龚美亮; 徐雅萍; 周玉; 方向群

    2012-01-01

    目的 评价头孢哌酮/舒巴坦(CFS)与利福平(RFP)、米诺环素(MIN)及左氧氟沙星(LEV)对临床分离碳青霉烯耐药鲍曼不动杆菌(CRAB)的体外联合抑菌作用.方法 采用棋盘法设计,微量肉汤稀释法测定抗菌药物对60株临床分离的CRAB的最低抑菌浓度(MIC),并计算抑菌指数(FIC指数)判断联合抑菌效应.结果 CFS与RFP联用后,80%为协同作用,16.7%为相加作用,3.3%为无关作用,无拮抗作用;CFS与MIN联用后,11.7%为协同作用,45%为相加作用,35%为无关作用,8.3%为拮抗作用;CFS与LEV联用时,6.7%为协同作用,40%为相加作用,53.3%为无关作用,无拮抗作用.上述药物联用后,各药MIC50均明显降低,浓度-累积抑菌率曲线均表现为左移.结论 CFS与RFP、MIN联用对CRAB体外联合抗菌效应主要表现为协同和相加作用.CFS与LEV联用主要表现为无关作用,但仍有近半数菌株表现为协同和相加作用.%Objective To evaluate the combined in vitro inhibitory effect of cefoperazone/sulbactam (CFS), rifampicin (RFP), minocycline(MIN) and levofloxacin(LEV) on clinically isolated carbapenem-resistant acinetobacter Baumannii (CRAB) strains. Methods Combined in vitro inhibitory effect of CFS, RFP, MIN and LEV was assayed by detecting the maximal inhibitory concentration and calculating the fractional inhibitory concentration (FIC ) index for 60 CRAB strains with the micro-broth dilution method. Results Combined CFS and RFP showed 80% synergic effect, 16.7% additive effect, 3.3% indifferent effect and no antagonistic effect on CRAB strains. Combined CFS and MIN displayed 11.7% synergic effect, 45% additive effect, 35% indifferent effect and 8.3% antagonistic effect on CRAB strains. Combined CFS and LEV demonstrated 6.7% synergic effect, 40% additive effect, 53.3% indifferent effect and no antagonistic effect on CRAB strains. The MIC50 of these drugs was significantly lower when they were used in combination with

  10. Molecular epidemiologic characterization of infection outbreaks caused by carbapenem-resistant Acinetobacter baumannii%耐碳青霉烯类鲍曼不动杆菌感染暴发的分子流行病学研究

    Institute of Scientific and Technical Information of China (English)

    孟小斌; 张国雄

    2013-01-01

    Objective To investigate the epidemiologic characteristics and drug resistance mechanism of carbapenem-resistant Acinetobacter baumannii (CRAB) isolated from a hospital, so as to guide prevention and control of healthcare-associated infection(HAI). Methods A total of 32 CRAB strains isolated clinically from January 2010 to May 2012 were performed genotyping by randomly amplified polymorphic DNA fingerprinting, and epidemiological analysis was conducted; carbapenemase were screened by modified Hodge test and EDTA-disk synergy test. The effect of efflux pump inhibitor carbonyl cyanide m-chlorophenyl hydrazone (CCCP)on minimum inhibitory concentration of meropenem was detected, efflux pump positive strains were screened. Results 32 CRAB strains displayed 9 kinds of genotypes, type A, H, I,B, E, and other types were 10,7,4,3,3,and 1-2 isolates respectively. From March to May,2012, 11 CRAB strains were isolated, type H,I,and A were 7,3, and 1 isolates respectively. 21 (65. 63%) CRAB strains expressed oxacillinase (OXA-23), and were positive in modified Hodge test (including 11 strains isolated in March-May, 2012); Except 1 isolate was detected New Delhi-Metallo-1 (NDM-1), all other strains were negative for metallo-lactamase test; the presence of CCCP slightly changed the MIC of meropenem to CRAB,all were negative for phenotype of efflux pump. CRAB strains were mainly isolated from patients in intensive care unit(13 isolates) and neurology department(7 isolates). Conclusion The outbreak of HAI of the clone with identical genotype occurred in this ICU between March and May, 2012. Carbapenem-resistance mechanism of A. baumannii can be attributed to the expression of OXA-23, and meropenem-resistance is not related to the efflux pump, CRAB strain expressing NDM-\\ has been detected in this hospital.%目的 分析某院耐碳青霉烯类鲍曼不动杆菌(CRAB)的分子流行病学特征和耐药机制,为预防和控制医院感染提供依据.方法 对该院2010年1

  11. Acinetobacter Baumannii Detected in Pediatric Infectious Diseases and Drug Resistance from 2006 to 2012%2006年~2012年不动杆菌在儿科感染性疾病中的检出率与耐药变迁

    Institute of Scientific and Technical Information of China (English)

    周颖; 徐曦巍; 宋文琪

    2013-01-01

    Objective The artical retrospectively researched on the changes and trends of the isolation rate and the drug resistance of Acinetobacter in pediatric infectious diseases, as well as the infection of pan-resistant Acinetobacter in pediatric diseases.Methods To select the bacterial samples of the children which outpatient and inpatient in Beijing Children's Hospital between 2006~2012 ,seperated 376 cases of Acinetobacter through bacterial culture, then researchzed on the detection in pediatric disease and the change of drug resistance, especially analyzed on the detected rate, laboratory characteristics and resistance mechanisms of Pan-resistant Acinetobacter retrospectively.Results In 376 Acinetobacter strains isolated from the bacterial samples, Bowman/calcium acetate Acinetobacter were checked out up to 158 strains, Acinetobacter baumannii strains were 171 strains, Acinetobacter La fite were 16 strains, Acinetobacter haemolyticus were 9 strains, Acinetobacter were 22 strains.Between 2006~2008, Institute of Respiratory Medicine in Beijing Children's Hospital had been the main detected ward of the Acinetobacter strains.Between 2009~2011, ICU ward had been the main detected ward of the Acinetobacter strains,followed by the blood and the surgical ward, the other strains isolated from neurology, dermatology, cardiology wards,and so on.The drug resistance of detected Acinetobacter to the selected drugs increased obviosly year by year, the detected rate of the pan-resistant Acinetobacter was in an increasing trend, the most significant growth had apperared between 2009~2010.Conclusion The deteced rate of Acinetobacter in pediatric clinical infections desease was increasing year by year,and the growth was rapidly,particularly in the ICU and the blood ward.The detected rate of the Pan-resistant Acinetobacter had increased significantly between 2009~2010, which should have been concerned extensively by clinical staff.It should be imminently to monitor the drug resistance

  12. An ace up their sleeve: a transcriptomic approach exposes the AceI efflux protein of Acinetobacter baumannii and reveals the drug efflux potential hidden in many microbial pathogens

    Directory of Open Access Journals (Sweden)

    Karl A Hassan

    2015-04-01

    Full Text Available The era of antibiotics as a cure-all for bacterial infections appears to be coming to an end. The emergence of multidrug resistance in many hospital-associated pathogens has resulted in superbugs that are effectively untreatable. Multidrug efflux pumps are well known mediators of bacterial drug resistance. Genome sequencing efforts have highlighted an abundance of putative efflux pump genes in bacteria. However, it is not clear how many of these pumps play a role in antimicrobial resistance. Several studies have demonstrated that efflux pump genes that participate in drug resistance are typically under tight regulatory control and expressed only in response to their substrates. Consequently, changes in gene expression following antimicrobial shock treatments may be used to identify efflux pumps that mediate antimicrobial resistance, informing targeted functional analyses of these proteins. Using this approach we have characterised novel efflux pumps in both Gram-negative and Gram-positive bacteria. Notably, we recently applied this strategy to characterise the AceI efflux pump from Acinetobacter. AceI is a prototype for a new family of multidrug efflux proteins that is conserved across many proteobacterial lineages. Different efflux pumps in this family have been shown to confer resistance to biocides including chlorhexidine, dequalinium, benzalkonium, proflavine and/or acriflavine. The discovery of this novel family of multidrug efflux proteins raises the possibility that additional undiscovered intrinsic resistance proteins may be encoded in the core genomes of pathogenic bacteria.

  13. Efficacy of continuous lumbar cisterna drainage with intrathecal polymyxin injection on treatment of intracranial infection by Acinetobacter baumannii after craniocerebral trauma surgery%腰大池持续引流加鞘内注射治疗颅脑创伤术后鲍氏不动杆菌颅内感染疗效分析

    Institute of Scientific and Technical Information of China (English)

    陈再丰; 许信龙; 傅小君; 魏晓捷; 潘红松; 谢青松

    2011-01-01

    OBJECTIVE To explore the treatment effect of continuous lumbar cisterna drainage and intrathecal colistin to intracranial infection of Acinetobacter baumannii. METHODS We cured 23 patients of intracranial infection of A. baumannii with the method of continuous lumbar cisterna drainage and intrathecal colistin. RESULTS In 23 patients of intracranial infection of A. baumannii, 2 patients died of central failure, 1 patient died of multiple organ failure and 1 patient require discharge in treatment. 19 patients were clinical cured and the cure rate was 82. 6%. 19 clinical cured patients were followed-up for 1 to 6 months, none of them caught intracranial infection again. CONCLUSION The treatment of intracranial infection of A. baumannii by continuous lumbar cisterna drainage and intrathecal colistin is a safe and effective treatment and with less complications.%目的 探讨腰大池持续引流加鞘内注射多黏菌素治疗鲍氏不动杆菌颅内感染的临床疗效.方法 采用腰大池持续引流加鞘内注射多黏菌素治疗23例颅脑创伤术后鲍氏不动杆菌感染的患者,观察临床疗效.结果 23例鲍氏不动杆菌颅内感染患者,2例死于中枢系统衰竭,1例死于多脏器衰竭,1例患者治疗过程中自动出院;19例临床治愈,治愈率82.6%;19例治愈病例均随访1~6个月,无一例再次发生颅内感染.结论 腰大池持续引流联合鞘内注射多黏菌素治疗鲍氏不动杆菌颅内感染是一种安全可行、疗效确切、并发症少的治疗方法.

  14. 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.

  15. Targeted investigation of nosocomial infections caused by multidrug-resistant Acinetobacter baumannii and analysis of drug resistance%多药耐药鲍氏不动杆菌医院感染目标性调查及耐药性分析

    Institute of Scientific and Technical Information of China (English)

    杨春玲; 宋平; 杨卉; 周传能

    2013-01-01

    目的 了解多药耐药鲍氏不动杆菌医院感染相关因素及其耐药性,以预防与控制多药耐药鲍氏不动杆菌医院感染的发生与流行.方法 采用前瞻性和回顾性调查方法,对医院2008年1月22日-2010年12月28日多药耐药及全耐药鲍氏不动杆菌感染的63例患者进行综合性分析.结果 多药耐药鲍氏不动杆菌感染患者中,36.5%为肺部感染合并多种基础性疾病,42.9%为多发性创伤骨折,73.0%入住过ICU,60.3%做过手术,38.1%~54.0%进行过各种侵入性操作,69.9%伴随混合菌感染;医院感染率为60.3%,总死亡率为31.7%,肺部感染死亡率高达71.4%;鲍氏不动杆菌耐药率高,其对头孢哌酮/舒巴坦的耐药率为15.9%,其次对亚胺培南的耐药率为31.7%,对其余抗菌药物耐药率达63.5%~100.0%.结论 加强对多药耐药鲍氏不动杆菌医院感染全方位预防和控制,尤其是对ICU的监控已经刻不容缓.%OBJECTIVE To investigate the relevant factors for nosocomial infections caused by multidrug-resistant Acinetobacter baumannii (MDRAB) and analyze its drug resistance so as to prevent and control the incidence and spreacl of MDRAB infections. METHODS By means of the prospective and retrospective survey, a total of 63 patients with multidrug-resistant A. baumannii and full drug-resistant A. baumannii infections, who enrolled the hospital form Jan 22, 2008 to Dec 28, 2010, were comprehensively analyzed. RESULTS Among the patients infected with multidrug-resistant A .baumannii, 36. 5% were with pulmonary infections complicated by multiple underlying diseases, 42. 9% were recurring traumatic fracture, 73. 0% have been hospitalized in ICU, 60. 3% have undergone the surgery, 38. l%-54. 0% undergoing various types of invasive operations, and 69. 9% were complicated by mixed infections. The incidence rate of nosocomial infections was 60. 3%, the overall mortality was 31. 7%, and the fatality rate was 71. 4% due

  16. Susceptibility and molecular mechanism of carbapenem -resistant Acinetobacter baumannii%耐碳青霉烯类抗生素鲍曼不动杆菌的药物敏感性及其分子特征

    Institute of Scientific and Technical Information of China (English)

    陈卫布; 吴伟元

    2014-01-01

    目的:调查重症监护病房(ICU)耐碳青霉烯鲍曼不动杆菌(CRAB)的药物敏感性及其分子特征。方法收集2010年深圳市人民医院ICU患者分离CRAB 48株,琼脂稀释法测定亚胺培南等15种抗菌药对CRAB的最低抑菌浓度(MIC),聚合酶链式反应(PCR)和DNA测序分析CRAB碳青霉烯酶基因型,脉冲场凝胶电泳( PFGE)分析菌株同源性。结果多黏菌素B对48株CRAB抗菌活性最高(敏感性为100%), MIC50/MIC90均为1μg · mL-1,其次为米诺环素,敏感性为95.8%,MIC50/MIC90均为4μg· mL-1,43株CRAB对替加环素中介,MIC50/MIC90均为4μg· mL-1。43株CRAB携带blaOXA-23-like ,对亚胺培南和美罗培南高度耐药,其MIC在16~64μg· mL-1;3株CRAB携带blaOXA-58-like,2株CRAB携带ISAba1-blaOXA-51-like ,亚胺培南和美罗培南的MIC在8~16μg· mL-1。48株CRAB扩增blaOXA-24-like、blaOXA-143-like、金属酶基因及KPC酶基因均阴性。48株CRAB经PFGE分型共分4型,以A型42株(87.5%)为主要流行克隆,均携带blaOXA-23-like。结论2010年携带blaOXA-23-like的CRAB高耐药克隆在我院ICU流行。%Objective To investigate the susceptibility of antimicrobial agents, carbapenemase genotypes and clonal relatedness among carbap-enem-resistant Acinetobacter baumannii ( CRAB) isolated from intensive care unit ( ICU) in Shenzhen People′s Hospital.Methods Forty-eight non-duplicated CRAB isolates were collected from ICU in this hospital in 2010.The minimum inhibitory concentrations ( MICs) of fifteen anti-microbial agents against CRAB were detected by agar dilution method.Polymerase chain reaction ( PCR) and DNA sequencing were used to in-vestigate the carbapenemase genotype among CRAB.All isolates were typed by pulse field gel electrophoresis ( PFGE ).Results Polymixin B showed the highest activity against forty-eight CRAB isolates ( suscepti-bility of 100%) , with the MIC50/MIC90 of 1 μg· mL -1 , followed

  17. 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

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

    Directory of Open Access Journals (Sweden)

    Adrián Golic

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

  19. Combined antimicrobial susceptibility test against pan-drug-resistant Acinetobacter baumannii with E-test and microdilution checkerboard assay%应用E-test法、肉汤微量稀释棋盘法检测泛耐药鲍曼不动杆菌的试验

    Institute of Scientific and Technical Information of China (English)

    王铁山; 苏建荣

    2013-01-01

    Objective To evaluate the activity of antibiotics against pan-drug-resistant (PDR) Acinetobacter baumannii by combination antimicrobial susceptibility test in viro with epsilometric methods (Etest method) and microdilution checkerboard (CB method),and to detect a good correlation between timekill curve with the above mentioned two assays.Methods Thirty-one clinical isolates of PDR Acinetobacter baumannii were selected for mono and combination antimicrobial susceptibility test in vitro by E-test and CB method,then a comparison was conducted between the test results and the time-kill curve.Mono drugs involved tigecycline,colistin,imipenem and amikacin,and combinations involved two of drugs above,and three drugs involved imipenem/tigecycline,plus amikacin combination.Results Synergistic effect was detected in imipenem plus colistin and tigecycline plus imipenem combination.A high comparability was revealed between the E-test method with antimicrobial drugs added into the culture medium and the time-kill curves.Synergy in the combination of imipenem/tigecycline,plus amikacin was detected by the CB method and time-kill curves.Conclusion The results showed that the effect of specific combination of antibiotics against PDR Acinetobacter baumannii could be predicted by testing their synergistic effect with combination antimicrobial susceptibility test.%目的 比较E-test法和肉汤微量稀释棋盘法(CB法)检测体外联合药敏试验并与时间杀菌曲线对比的观察.方法 选择31株泛耐药(PDR)鲍曼不动杆菌临床株进行体外试验,分为替加环素、可立其丁、亚胺培南、阿米卡星单用和两药组合,亚胺培南+替加环素+阿米卡星三药组合也由CB法测试.这些测试的结果与时间杀菌曲线进行比较.结果 亚胺培南+可立其丁、替加环素+亚胺培南能检测到协同作用.培养基中加入抗菌药物的E-test法联合药敏试验与时间杀菌曲线更具有可比性.在三药组合中由CB法和

  20. 鲍曼不动杆菌生物膜形成能力与生物膜相关基因及耐药性之间的关系%Correlation between the biofilm-forming ability, biofilm-related genes and antimicrobial resistance of Acinetobacter baumannii

    Institute of Scientific and Technical Information of China (English)

    韩欣欣; 李庆淑; 申丽婷; 胡丹; 曲彦

    2014-01-01

    Objective To study the biofilm-forming ability and the distribution of biofilm-related genes in Acinetobacter baumannii clinical isolates as well as antimicrobial resistance,to analyze their relationships with the bacterial resistance phenotype.Methods A prospective study was conducted.Biofilm models of 70 strains Acinetobacter baumannii collected in Chengwu County People's Hospital from October 2012 to October 2013 were constructed using 96-well polystyrene plate.In order to analyze the biofilm-forming ability,a qualitative and quantitative analysis was conduct by crystal violet staining assay.And the antimicrobial resistance of different biofilm-forming ability strains was compared including imipenem,amikacin,meropenem,cefepime,sulbactam cefoperazone,trimethoprim,levofloxacin,gentamicin,ciprofloxacin,cefotaxime,ceftizoxime,aztreonam,piperacillin,ceftriaxone,cefuroxime.In addition,the expressions of biofilm-related gene Bap,bfs and intI1 were tested with polymerase chain reaction (PCR) assay.Results Among 70 strains Acinetobacter baumannii,40 strains were multi-drug resistant (57.14%) and 6 strains were pan-drug resistant (8.57%); 68 strains had biofilm-forming ability (97.14%),14 of which were weakly positive,20 were positive and 34 were strongly positive.The antimicrobial resistant rate of Acinetobacter baumannii to imipenem,amikacin,meropenem and cefepime was decreased,it was 30.00%,32.86%,38.57% and 41.43%,respectively.However,the antimicrobial resistant rates to other commonly used antibiotics were all higher than 50%.The drug resistance of Acinetobacter baumannii to levofloxacin (85.71%,45.00%,38.24%,x2=9.225,P=0.010),cefepime (71.43%,45.00%,29.41%,x2=7.222,P=0.027),gentamicin (78.57%,55.00%,38.24%,x2 =6.601,P=0.037) was significantly decreased when biofilm-forming ability reinforced (weakly positive,positive,hadro-positive).Bap gene positive rate of weakly positive,positive and strong positive biofilm-forming strains

  1. 临床药师参与治疗鲍曼不动杆菌颅内感染患儿的药学实践%Clinical pharmacists participated in the treatment of Acinetobacter baumannii in- tracranial infections in children

    Institute of Scientific and Technical Information of China (English)

    何霜霜; 刘腾

    2015-01-01

    Objective To provide reference for clinical pharmacist and physicians working together to treat se-vere refractory Acinetobacter baumanniii ntracranial infections in children. Methods The process of clinical pharmacist participating indrug therapy for the patient suffering from Acinetobacter baumannii intracranial infections in children was retrospectively analyzed. The clinical pharmacist can closely cooperate with the physicians by using their pharma-ceutical knowledge and the evidence-based literatures. Results The children was finally cured and discharged from hospital. Conclusion Clinical pharmacists′ participation is helpful for doctors to make safe and effective medication.%目的:为临床救治重症难治性鲍曼不动杆菌颅内感染患儿提供用药参考。方法通过分析临床药师参与救治我院1例鲍曼不动杆菌颅内感染患儿提供的药学服务,根据患者的病情变化,临床药师结合药物的药理药化知识,查阅相关文献资料,与临床医师共同协商,制定出最优的药物治疗方案。结果通过临床医师及临床药师的共同努力,最终成功救治该患儿。结论临床药师的参与可以协助医师制订安全、有效的治疗方案。

  2. 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

    OpenAIRE

    Gupta, V.; Garg, R.; Garg, S.; J Chander; Attri, A.K.

    2013-01-01

    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, Am...

  3. 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

  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. 经纤维支气管镜阿米卡星肺泡灌洗治疗多重耐药鲍曼不动杆菌呼吸机相关性肺炎的临床观察%Clinical Observation of Treatment on Multidrug-resistant Acinetobacter Baumannii Ventilator-associated Pneumonia with Amikacin by Fiberoptic Bronchoscopy Lavage

    Institute of Scientific and Technical Information of China (English)

    吕光宇; 蒋文芳; 蔡天斌; 张友华

    2015-01-01

    目的:评估经纤维支气管镜阿米卡星肺泡灌洗治疗多重耐药治疗鲍曼不动杆菌(multidrug-resistant acinetobacter baumanii,MDR-Ab)呼吸机相关肺炎(ventilator-associated pneumonia,VAP)的效果和安全性。方法将42例多重耐药鲍曼不动杆菌呼吸机相关性肺炎的机械通气患者随机分为观察组和对照组,每组21例。两组均使用头孢哌酮舒巴坦钠3.0 g,1次/6小时并每日行支气管肺泡灌洗吸痰,观察组每日支气管肺泡灌洗治疗结束后用阿米卡星0.4 g加10 mL生理盐水灌洗,对照组使用阿米卡星7.5 mg/kg静脉滴注1次/天。记录治疗前后急性生理与慢性健康评分Ⅱ(acute physiology and chronic health evaluation Ⅱ,APACHE Ⅱ)、临床肺部感染评分(clinical pulmonary infection score,CPIS)、血清肌酐(Cr)、C-反应蛋白(CRP),比较两组治疗结束时支气管肺泡灌洗液细菌学检查转阴率、28 d病死率。结果与治疗前相比,两组APACHEⅡ评分、CPIS、CRP治疗后均有下降(P0.05), while the control group has signiifcantly higher levels of Cr than before treatment (P0.05)]. Conclusion Treatment of multidrug-resistant acinetobacter baumannii ventilator-associated pneumonia by ifberoptic bronchoscopy lavage was better than intravenous administration of amikacin, and can achieve higher bacterial clearance rate, while effectively reducing nephrotoxicity.

  6. Survey on multi-drug resistant acinetobacter baumannii with beta lactam drugs drug resistant gene%多重耐药鲍曼不动杆菌携带β-内酰胺类药物耐药基因研究

    Institute of Scientific and Technical Information of China (English)

    刘广锋; 吕守彦

    2014-01-01

    目的:调查临床分离的10株多重耐药鲍曼不动杆菌(MDR-Ab)对常用的氨基糖苷类、β-内酰胺类、氯霉素、喹诺酮类、四环素、磺胺类和利福平等抗菌药物的耐药情况及其携带β-内酰胺类药物耐药基因的存在状况进行调查。方法10株试验菌均分离自2012年1月至2013年12月该院住院患者痰液标本,排除某一患者重复分离菌株。采用K-B纸片扩散法测定21种抗菌药物的敏感性,并用聚合酶链反应(PCR)检测β-内酰胺酶类、金属β-内酰胺酶类、碳青酶烯类及AmpC酶类等耐药基因。结果该MDR-Ab对21种抗菌药物均为耐药,共检出TEM、OXA-2、ADC、CTX-M-1、CTX-M-2、IMP、OXA-24等耐药基因。结论多重耐药鲍曼不动杆菌可能对目前临床常用的β-内酰胺类药物存在着广泛耐药。%Objective Survey on drug resistance situation of clinically separated 10 multi-drug resistant acinetobacter baumannii(MDR-Ab) for commonly-used beta lactam class,aminoglycosides,chloromycetin,quinolones,sulfonamides and rifampicin and sulfa,etc and existence condition of resistant gene of carried beta lactam drugs. Methods The 10 test bacteria of sputum specimen separated from the inpatients from Jan. 2012 to Dec. 2013 excluding re-separation from a patient was adopted K-B dif-fusion method to detect sensibility of 21 antimicrobial agents,and beta lactam drugs,metal beta la-ctam enzymes,carbapenms and AmpC enzymes. Results The MDR-Ab was resistant to 21 antibacterial drugs,detecting TEM,OXA-2,ADC,CTX-M-1,CTX-M-2、IMP、OXA-24 and so on. Conclusion Multi-drug resistant acinetobacter baumannii(MDR-Ab) may be extensively resistant to currently-used beta lactam drugs.

  7. Study of broad-spectrum antibiotics and antiseptics resistance genes in Acinetobacter baumannii strains isolated from burned patients%鲍曼不动杆菌烧伤分离株广谱抗生素及消毒剂耐药基因研究

    Institute of Scientific and Technical Information of China (English)

    程华莉; 潘宇红; 黄璇; 吕国忠; 朱婕; 糜祖煌; 张烽

    2011-01-01

    目的 研究鲍曼不动杆菌烧伤分离