scholarly journals Carbapenemase Production of Clinical Isolates Acinetobacter baumannii and Pseudomonas aeruginosa from a Bulgarian University Hospital

Folia Medica ◽  
2017 ◽  
Vol 59 (4) ◽  
pp. 413-422 ◽  
Author(s):  
Atanaska P. Petrova ◽  
Irina D. Stanimirova ◽  
Ivan N. Ivanov ◽  
Michael M. Petrov ◽  
Tsonka M. Miteva-Katrandzhieva ◽  
...  

AbstractBackground: Production of Bla OXA-23, OXA-24, OXA-58 and hyperexpression of OXA-51 due to ISAba1 insertion sequence are the leading causes of carbapenem resistance in Acinetobacter baumannii. The loss of OprD transmembrane protein and the overexpression of some effl ux pumps are considered to be the main factors for carbapenem resistance in Pseudomonas aeruginosa whereas metallo-enzymes’ production has a secondary role. Aim: Тo examine the carbapenem resistance due to carbapenemase production among clinically signifi cant Gram-negative non-fermenters from St George University hospital, Plovdiv: A. baumannii and P. aeruginosa. Materials and methods: Forty three A. baumannii and 43 P. aeruginosa isolates, resistant or with intermediate resistance to imipenem and/or meropenem were included in the study. They were collected from patients admitted in 14 various hospital wards between 2010 and 2014. Both phenotypic and genetic methods were used for identifi cation and antimicrobial susceptibility testing. Results: All A. baumannii demonstrated carbapenemase production determined by a modifi ed Hodge test whereas P. aeruginosa isolates did not show this phenomenon. OXA-23 genes were determined in 97.7% (42 out of 43) of A. baumannii isolates indistinguishable from the sequence of the classical ARI-1 gene. OXA-24, OXA-58 and overexpression of OXA-51 were not registered in any of the isolates. All P. aeruginosa were negative for blaVIM and blaIMP genes. Conclusion: The leading cause of carbapenem resistance in A. baumannii isolates from our hospital is the carbapenemase production due to the expression of OXA- 23 gene, whereas in P. aeruginosa - the loss of transmembrane OprD protein and the effl ux pumps’ hyperexpression are suspected to be the main mechanisms.

2008 ◽  
Vol 52 (11) ◽  
pp. 4115-4120 ◽  
Author(s):  
Raffaele Zarrilli ◽  
Domenico Vitale ◽  
Anna Di Popolo ◽  
Maria Bagattini ◽  
Ziad Daoud ◽  
...  

ABSTRACT We investigated the basis of the carbapenem resistance of 17 multidrug-resistant Acinetobacter baumannii clinical isolates collected from 2004 to 2005 at the Saint George University Hospital in Beirut, Lebanon. A. baumannii isolates were clonally related and were susceptible to colistin and trimethoprim-sulfamethoxazole, susceptible or intermediate to ampicillin-sulbactam and meropenem, and resistant to all other antimicrobials. Conjugation experiments demonstrated that resistance to imipenem could be transferred along with a plasmid containing the carbapenem-hydrolyzing oxacillinase bla OXA-58 gene. The plasmid that we called pABIR was 29,823 bp in size and showed a novel mosaic structure composed of two origins of replication, four insertion sequence (IS) elements, and 28 open reading frames. The bla OXA-58 gene was flanked by IS18 and ISAba3 elements at the 5′ and 3′ ends, respectively. The production of the carbapenem-hydrolyzing oxacillinase OXA-58 was apparently the only mechanism for carbapenem resistance in A. baumannii isolates causing the outbreak at the Lebanese Hospital.


2016 ◽  
Vol 54 (7) ◽  
pp. 1700-1710 ◽  
Author(s):  
Thomas J. Gniadek ◽  
Karen C. Carroll ◽  
Patricia J. Simner

The non-glucose-fermenting Gram-negative bacilliPseudomonas aeruginosaandAcinetobacter baumanniiare increasingly acquiring carbapenem resistance. Given their intrinsic antibiotic resistance, this can cause extremely difficult-to-treat infections. Additionally, resistance gene transfer can occur between Gram-negative species, regardless of their ability to ferment glucose. Thus, the acquisition of carbapenemase genes by these organisms increases the risk of carbapenemase spread in general. Ultimately, infection control practitioners and clinical microbiologists need to work together to determine the risk carried by carbapenem-resistant non-glucose-fermenting Gram-negative bacilli (CR-NF) in their institution and what methods should be considered for surveillance and detection of CR-NF.


2018 ◽  
Vol 63 (2) ◽  
pp. e01040-18 ◽  
Author(s):  
Sean M. Stainton ◽  
Marguerite L. Monogue ◽  
Masakatsu Tsuji ◽  
Yoshinori Yamano ◽  
Roger Echols ◽  
...  

ABSTRACT Herein, we evaluated sustainability of humanized exposures of cefiderocol in vivo over 72 h against pathogens with cefiderocol MICs of 0.5 to 16 μg/ml in the neutropenic murine thigh model. In Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacteriaceae displaying MICs of 0.5 to 8 μg/ml (n = 11), sustained kill was observed at 72 h among 9 isolates. Postexposure MICs revealed a single 2-dilution increase in one animal compared with controls (1/54 samples, 1.8%) at 72 h. Adaptive resistance during therapy was not observed.


2015 ◽  
Vol 59 (4) ◽  
pp. 2280-2285 ◽  
Author(s):  
Robert K. Flamm ◽  
Paul R. Rhomberg ◽  
Ronald N. Jones ◽  
David J. Farrell

ABSTRACTRX-P873 is a novel antibiotic from the pyrrolocytosine series which exhibits high binding affinity for the bacterial ribosome and broad-spectrum antibiotic properties. The pyrrolocytosines have shownin vitroactivity against multidrug-resistant Gram-negative and Gram-positive strains of bacteria known to cause complicated urinary tract, skin, and lung infections, as well as sepsis.Enterobacteriaceae(657),Pseudomonas aeruginosa(200), andAcinetobacter baumannii(202) isolates from North America and Europe collected in 2012 as part of a worldwide surveillance program were testedin vitroby broth microdilution using Clinical and Laboratory Standards Institute (CLSI) methodology. RX-P873 (MIC90, 0.5 μg/ml) was >32-fold more active than ceftazidime and inhibited 97.1% and 99.5% ofEnterobacteriaceaeisolates at MIC values of ≤1 and ≤4 μg/ml, respectively. There were only three isolates with an MIC value of >4 μg/ml (all were indole-positiveProtea). RX-P873 (MIC50/90, 2/4 μg/ml) was highly active againstPseudomonas aeruginosaisolates, including isolates which were nonsusceptible to ceftazidime or meropenem. RX-P873 was 2-fold less active againstP. aeruginosathan tobramycin (MIC90, 2 μg/ml; 91.0% susceptible) and colistin (MIC90, 2 μg/ml; 99.5% susceptible) and 2-fold more potent than amikacin (MIC90, 8 μg/ml; 93.5% susceptible) and meropenem (MIC90, 8 μg/ml; 76.0% susceptible). RX-P873, the most active agent againstAcinetobacter baumannii(MIC90, 1 μg/ml), was 2-fold more active than colistin (MIC90, 2 μg/ml; 97.0% susceptible) and 4-fold more active than tigecycline (MIC90, 4 μg/ml). This novel agent merits further exploration of its potential against multidrug-resistant Gram-negative bacteria.


2021 ◽  
Vol 8 (8) ◽  
pp. 429-434
Author(s):  
Atit Dineshchandra Shah ◽  
Urvashi Natubhai Limbachia ◽  
Bhavin K. Prajapati ◽  
Lata Patel ◽  
Dharati Tusharbhai Shah ◽  
...  

BACKGROUND Non fermenting gram-negative bacilli (NFGNB) are a group of heterogenous, aerobic and non-sporing saprophytic bacteria, found as commensals in humans and other animals primarily causing opportunistic healthcare-associated infections. They are innately resistant to many antibiotics and are known to acquire resistance by various mechanisms. They pose a particular difficulty for the healthcare community because multidrug resistance is common and increasing among them and a number of strains have now been identified that exhibit pan drug resistance. This study was conducted to isolate and identify various non-fermenter gram negative bacilli (NFGNB), to study their antibiotic sensitivity pattern and their clinical significance from various clinical samples. METHODS A study was undertaken from March 2019 to February 2020 to isolate NFGNB from various clinical samples received for culture and sensitivity in the department of microbiology in a tertiary care hospital, Ahmedabad. Non lactose fermenting colonies on MacConkey agar plates were further processed by Vitek 2 to identify them and to study their antimicrobial susceptibility testing (AST). RESULTS A total of 2010 NFGNB were isolated from various clinical samples and their AST was evaluated by Vitek 2. Pseudomonas aeruginosa (52.7 %) and Acinetobacter baumannii (36.5 %) were the most common NFGNB isolated. Carbapenem resistance was 93 % for Acinetobacter species and 61 % for Pseudomonas species. CONCLUSIONS Accurate and rapid identification and antimicrobial susceptibility testing of NFGNB help in early initiation of appropriate antimicrobial therapy and proper management of patients thereby help in reducing emergence of MDR strains of NFGNB, mortality and overall hospital stay. KEYWORDS NFGNB – Non-Fermenting Gram-Negative Bacilli, Multidrug Resistance, Pan Drug Resistance, Carbapenem Resistance


2018 ◽  
Vol 10 (02) ◽  
pp. 208-213 ◽  
Author(s):  
Jayanthi Siva Subramaniyan ◽  
Jeya Meenakshi Sundaram

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


Author(s):  
Einas A Bakheit ◽  
Kamal M Elhag ◽  
Abduelmula R Abduelkarem ◽  
Nada A Basheer

Objectives: The objective of this study was to describe patterns of antimicrobial resistance to gentamicin (Gen) and amikacin (Ak) among Gram-negative aerobic bacteria during 1-year period and to determine the association between antibiotic resistance and the consumption of Gen.Methods: Aminoglycosides consumption at Soba University Hospital wards was measured and susceptibility of Gram-negative bacteria for the same period was evaluated. Consumption data were converted to defined daily doses (DDDs)/100 bed days based on DDD/anatomical therapeutic chemical the WHO system. The association between the frequency of strains resistant to Gen and Ak and their consumption was assessed by linear regression analysis using Spearman’s correlation. The level of statistical significance was set at p<0.05.Results: A total of 973 Gram-negative isolates were identified and tested for antimicrobial susceptibility to Gen and Ak. Resistance to Gen alone was found to be 19.42%; n=189, resistance to Ak alone was found to be 3.08%; n=30, and resistance to Gen plus Ak was found to be 5.24%; n=51. Pseudomonas aeruginosa was the most resistant pathogen to Ak plus Gen (2.26%; n=22). A positive correlation between the increases in the use of Gen and the prevalence of bacterial resistance among hospital wards was found (correlation coefficient r=0.6; p=0.04).Conclusion: Gen and Ak are still highly active antimicrobial agents for the treatment of aerobic Gram-negative bacteria at times of intensified resistance to other antimicrobial agents. Monitoring the use of aminoglycosides is very important too. 


2009 ◽  
Vol 15 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Jian-Fang Zhang ◽  
Bi-Liang Chen ◽  
Xiao-Yan Xin ◽  
Hai-Bo Zhao ◽  
Hong-Ying Wang ◽  
...  

2013 ◽  
Vol 58 (3) ◽  
pp. 1763-1767 ◽  
Author(s):  
L. V. Perdigão-Neto ◽  
M. S. Oliveira ◽  
C. F. Rizek ◽  
C. M. D. M. Carrilho ◽  
S. F. Costa ◽  
...  

ABSTRACTFosfomycin may be a treatment option for multiresistant Gram-negative bacteria. This study compared susceptibility methods using 94 multiresistant clinical isolates. With agar dilution (AD), susceptibilities were 81%, 7%, 96%, and 100% (CLSI) and 0%, 0%, 96%, and 30% (EUCAST), respectively, forAcinetobacter baumannii,Pseudomonas aeruginosa,Klebsiella pneumoniae, andEnterobacterspp. Categorical agreement between Etest and AD forEnterobacteriaceaeandA. baumanniiwas ≥80%. Disk diffusion was adequate only forEnterobacter. CLSI criteria for urine may be adequate for systemic infections.


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