scholarly journals Susceptibility Testing of Colistin for Acinetobacter baumannii: How Far Are We from the Truth?

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 48
Author(s):  
Federica Sacco ◽  
Paolo Visca ◽  
Federica Runci ◽  
Guido Antonelli ◽  
Giammarco Raponi
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care ◽  
Clinical Samples ◽  
Clonal Lineage ◽  
Sequence Group ◽  
Susceptibility Data ◽  
Carbapenem Resistant ◽  
Drug Concentrations ◽  
Therapeutic Opportunity ◽  
Group 2

Acinetobacter baumannii is involved in life-threatening nosocomial infections, mainly in the intensive care units (ICUs), and often colistin may represent the last therapeutic opportunity. The susceptibility to colistin of 51 epidemiologically typed A. baumannii strains isolated in 2017 from clinical samples of patients hospitalized in the ICU of a tertiary care academic hospital was investigated. All isolates were carbapenem-resistant due to the presence of the blaOXA-23 gene in sequence group 1 (international clonal lineage II) and sequence group 4 (related to international clonal lineage II) isolates, and to the blaOXA-24/40 gene in sequence group 2 (international clonal lineage I) isolates. Vitek®2, agar diffusion, and broth microdilution tests showed major discordancy (≥2 dilution factors) in the minimum inhibitory concentration (MIC) values for colistin in 24 out of 51 isolates, resulting in erroneous reporting of qualitative susceptibility data for eight isolates. In growth kinetics experiments in the presence of colistin, five isolates grew with drug concentrations above the susceptibility breakpoint when incubated for >12 h, and three isolates showed the presence of heteroresistant subpopulations. This study highlights that the high frequency of isolation of carbapenem-resistant A. baumannii strains in high-risk infectious wards requires an accurate application of methods for detecting susceptibility to antibiotics, in particular to colistin, so as to ensure a correct therapeutic approach.

scholarly journals Identification, Speciation and Antibiogram along with Detection of Metallo Beta-lactamase Production in Acinetobacter Isolated from Clinical Samples in a Tertiary Care Hospital

2021 ◽  
Author(s):  
N Ashwin Chitrabanu ◽  
Shrikara Mallya
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care ◽  
Antibiotic Sensitivity ◽  
Clinical Samples ◽  
Care Hospital ◽  
Acinetobacter Species ◽  
Carbapenem Resistant ◽  
Appropriate Treatment ◽  
Sensitivity Pattern ◽  
Synergy Test

Acinetobacter species are gram negative non fermenters, which are important nosocomial pathogens involved in various outbreaks in hospitals due to widespread resistance to majority antibiotics. The aim of this study is to speciate Acinetobacter isolated from clinical samples, to assess the antibiotic sensitivity pattern and to detect the production of metallo-β-lactamase by double disc synergy test. The study was conducted in the department of microbiology, A. J Institute of Medical Sciences. All clinical samples were subjected to gram stain & cultured; the Acinetobacter isolates obtained were subjected to antibiogram. Those isolates that showed Imipenem resistant were further tested for production of metallo-β-lactamase by double disc synergy test. Out of 6625 culture positive isolates, 414 (36.1%) were identified biochemically to belong to Acinetobacter species. Of the 414 cases, 393 (94.9%) were further identified to be Acinetobacter baumannii and the remaining 21 (5.1%) to be Acinetobacter lwoffi. Acinetobacter lwoffii showed 100% sensitivity to all the drugs. Of the 393 Acinetobacter baumannii isolates 109 (27.7%) showed resistant to Imipenem. Out of these 109 isolates, 65 (59.63%) were positive for metallo-β-lactamase production by double disk synergy test. The speciation is highly demanding and laborious but it’s important to be demonstrated due to difference in the antibiotic susceptibility pattern. Carbapenem resistant Acinetobacter nosocomial strains in ICUs are detected to be more resistant to antibiotics. As shown in this study the metallo-β-lactamase producing A.baumannii isolates were 59.63% and therapeutic options were limited. Therefore early identification of metallo-β-lactamase producers is of great importance to start appropriate treatment and to control the spread.

scholarly journals Molecular Characterization Identifies Upstream Presence of ISAba1 to OXA Carbapenemase Genes in Carbapenem-Resistant Acinetobacter baumannii Isolated from a Tertiary Care Hospital in Western Maharashtra

2021 ◽  
Author(s):  
Nageswari Gandham ◽  
Neetu Gupta ◽  
Chanda Vyawahare ◽  
Shahzad Beg Mirza ◽  
Rabindra Nath Misra
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Clinical Samples ◽  
Care Hospital ◽  
Carbapenem Resistant ◽  
Resistant Strains ◽  
Polymerase Chain ◽  
Antibiotics Sensitivity

Abstract Background Evaluating the expression pattern of oxacillinases (OXA) carbapenemases is essential to understand the prevalence and spread of carbapenem resistance Acinetobacter baumannii. Objectives The aim of the study is to evaluate the presence of OXA carbapenemase genes and ISAba1 upstream to these genes in carbapenem-resistant A. baumannii clinical isolates. Material and Methods A. baumannii isolated from clinical samples were phenotypically identified and antibiotics sensitivity was performed. Multiplex polymerase chain reaction (PCR) was used to detect OXA51-like gene, OXA carbapenemases genes (OXA-23-like, OXA-24-like, and OXA-58-like), and ISAba1 in carbapenem-resistant isolates. Results Out of 55 Acinetobacter isolates, 54 were confirmed as A. baumannii by PCR. Bla OXA-23-like gene was observed in 51 isolates of A. baumannii and none of the isolates showed the presence of bla OXA-24-like and bla OXA-58-like genes. Presence of ISAba1 upstream to OXA-23-like gene, OXA-51-like gene, and both OXA-51-like/OXA-23-like genes was observed in 51, 7, and 4 A. baumannii isolates, respectively. Conclusion The genetic pattern of carbapenem-resistant A. baumannii isolated in this study was unique, which should be factored for clinical protocols to manage infections caused by emerging resistant strains of A. baumannii.

scholarly journals MOLECULAR EPIDEMIOLOGY OF METALLO BETA LACTAMASES IN ACINETOBACTER BAUMANNII AT A TERTIARY CARE HOSPITAL

2019 ◽  
Vol 3 (8) ◽  
Author(s):  
Sulaiman A Mohammed ◽  
Dr. Suman P Singh
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Care Hospital ◽  
Sensitivity Testing ◽  
Beta Lactamases ◽  
Carbapenem Resistant ◽  
Significant Difference ◽  
Vitek 2

Background: Carbapenem resistance mediated by metallo beta lactamases (MBL) in Acinetobacter baumannii is a global challenge due to its rapid spread and limited therapeutic options. Objective: To determine the prevalence of MBL in A. baumannii isolates in hospitalized patients by both phenotypic and genotypic methods. Materials and Methods: The clinical samples were collected from inpatients and subcultured on routine culture media for growth. Identification of bacteria along with antimicrobial sensitivity testing was done by VITEK -2 Compact (bioMerieux). Antibiotics that were not tested by VITEK-2 were tested manually by Kirby-Bauer disk diffusion method according to CLSI 2017 and EUCAST 2016 guidelines. The isolates which were resistant to carbapenem (imipenem and/ or meropenem) were tested by phenotypic (imipenem-EDTA combined disk method) and genotypic method for presence of common metallo beta lactamases genes (blaIMP, blaNDM, blaGIM, blaVIM, blaSPM and blaSIM). Results: 84 non duplicate A.baumannii were isolated out of 947 pathogenic gram negative isolates. Majority (47.6%) of isolates were obtained from tracheostomy/endotracheal/bronchoalveolar lavage (TT/ET/BAL) followed by sputum (21.4%). None of the isolates were found to be resistant to colistin and tigecycline. 73 (86.9%) isolates were found to be carbapenem resistant, among these 60 (82.2%) were found to be MBL positive by phenotypic and 32 (43.2%) by genotypic method. MBL genes detected were blaNDM (39.7%), blaGIM (2.7%) and blaVIM (1.4%). None of the isolates were positive for blaIMP, blaSPM and blaSIM. Conclusion:  The prevalence of MBL in carbapenem resistant isolates of A.baumannii was 87.7%.  blaNDM was the most common gene detected. No significant difference was found in the ability of phenotypic and genotypic methods for MBL detection. The resistance rate of the A.baumannii is high for most antibiotics except for polymyxins (E&B) and tigecycline. Key words: Metallo beta Lactamases, Acinetobacter baumannii, Carbapenem.

Molecular detection of blaOXA-23gene and blaOXA-51 gene in carbapenem resistant strains of Acinetobacterbaumannii in patients with ventilator associated pneumonia at tertiary care hospital

2021 ◽  
Vol 71 (11) ◽  
pp. 2576-2581
Author(s):  
Saima Ishtiaq ◽  
Sidrah Saleem ◽  
Abdul Waheed ◽  
Arslan Ahmed Alvi
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Conventional Polymerase Chain Reaction ◽  
Diffusion Method ◽  
Military Hospital ◽  
Care Hospital ◽  
Acinetobacter Baumanii ◽  
Cross Sectional ◽  
Carbapenem Resistant

Objective: To evaluate carbapenem resistance and to detect blaOXA-23 and blaOXA-51 genes in carbapenem-resistant acinetobacter baumanii isolates recovered from patients having pneumonia secondry to ventilation. Methods: The cross-sectional study was conducted from July 2017 to June 2018 at the Department of Microbiology, University of Health Sciences, Lahore, Pakistan, and comprised endotracheal aspirates / tracheobroncheal lavage samples from patients irrespective of age and gender who developed pneumonia after being on the ventilator for 48 hrs at the Combined Military Hospital, and Jinnah Hospital, Lahore.  The samples were inoculated on MacConkey and blood agar and aerobically incubated at a temperature of 370C for 18-24 hours. The isolated organisms were further assessed by standard morphological, cultural and biochemical profile. Antibiotic susceptibility was done by Kirby-Bauer disc diffusion method. Carbapenem-resistant acinetobacter baumannii were checked for carbapenemase production using Modified Hodge Test. Conventional polymerase chain reaction and agarose gel electrophoreses were performed to detect blaOXA-23 and blaOXA-51 genes. Data was analysed using SPSS 17. Results: Out of 157 samples, 92(58.6%) yielded growth of bacteria, and, among them, 39(42.4%) were identified as acinetobacter baumannii. All (100%) acinetobacter baumannii cases showed resistance to carbapenem, were producing carbapenemase enzyme, and were positive for blaOXA-51 gene. The blaOXA-23 gene was amplified in 38(97.4%) isolates. Conclusion: BlaOXA-23 gene appeared to be the major cause of carbapenem resistance. Continuous...

scholarly journals Epidemiology of carbapenem-resistant Enterobacteriaceae in a Tertiary Care Center in the Kingdom of Bahrain

2019 ◽  
Vol 11 (02) ◽  
pp. 111-117 ◽  
Author(s):  
Nermin Kamal Saeed ◽  
Safaa Alkhawaja ◽  
Nashawa Fawzy Abd El Moez Azam ◽  
Khalil Alaradi ◽  
Mohammed Al-Biltagi
Keyword(s):  
Control Measure ◽  
Care Center ◽  
Tertiary Care ◽  
Laboratory Data ◽  
Control Measures ◽  
Clinical Samples ◽  
Common Source ◽  
Care Hospital ◽  
Carbapenem Resistant ◽  
Carbapenem Resistant Enterobacteriaceae

Abstract PURPOSE: The purpose of the study is to estimate the rate of infection with carbapenem-resistant Enterobacteriaceae (CRE) in the main governmental tertiary care hospital in Bahrain. MATERIALS AND METHODS: All clinical samples with positive growth of CRE over 6-year period (January 2012–December 2017) were collected from the microbiology laboratory data. RESULTS: The CRE incidence was high in the first half of study period (2012–2014) and then decreased between 2015 and 2017, after implementation of intensified CRE control measure bundle. About 49.4% of CRE-positive samples were isolated from the elderly age group (above 65 years old), most of them were admitted in the intensive care unit (ICU). The most common isolated organisms were Klebsiella pneumoniae (87.0%), followed by Escherichia coli (7.9%). Isolates from deep tracheal aspirate and midstream urine specimens were the most common source of CRE isolates (27.3%) and (26.3%), respectively. Bacteremia was documented in 21.2% of cases. CRE isolates in the study showed high rates of resistance to aminoglycosides (72.2% resistant to amikacin and 67.3% to gentamicin). Alternatively, most isolates retained their susceptibility to colistin and tigecycline with sensitivity of 83.9% and 85.7%, respectively. Combined resistance to both colistin and tigecycline was observed in 0.06% of total isolates. CONCLUSION: Elderly population and ICU admission were important risk factors for CRE acquisition. Most of CRE isolates were sensitive to both colistin and tigecycline, which make them the best combination for empiric frontline therapy for suspected serious CRE infection in our facility. Implementing CRE-bundled infection control measures significantly reduced the incidence of CRE infection in our hospital.

scholarly journals Molecular Characterization of Invasive Carbapenem-Resistant Acinetobacter baumannii from a Tertiary Care Hospital in South India

2016 ◽  
Vol 5 (3) ◽  
pp. 379-387 ◽  
Author(s):  
Saranya Vijayakumar ◽  
Radha Gopi ◽  
Priya Gunasekaran ◽  
Manjurekar Bharathy ◽  
Kamini Walia ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Molecular Characterization ◽  
South India ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Care Hospital ◽  
Carbapenem Resistant

scholarly journals Reduction in Fluoroquinolone Use following Introduction of Ertapenem into a Hospital Formulary Is Associated with Improvement in Susceptibility of Pseudomonas aeruginosa to Group 2 Carbapenems: a 10-Year Study

2011 ◽  
Vol 55 (12) ◽  
pp. 5597-5601 ◽  
Author(s):  
Paul P. Cook ◽  
Michael Gooch ◽  
Shemra Rizzo
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pearson Correlation ◽  
Tertiary Care ◽  
Carbapenem Resistance ◽  
Antibiotic Use ◽  
Care Hospital ◽  
Hospital Formulary ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Group 2

ABSTRACTWe examined the effect of the addition of ertapenem to our hospital formulary on the resistance of nosocomialPseudomonas aeruginosato group 2 carbapenems (imipenem, meropenem, and doripenem). This was a retrospective, observational study conducted between 1 January 2000 and 31 January 2009 at a large, tertiary-care hospital. Autoregressive integrated moving average (ARIMA) regression models were used to evaluate the effect of ertapenem use on the susceptibility ofPseudomonas aeruginosato group 2 carbapenems as well as on the use of the group 2 carbapenems, ciprofloxacin, and other antipseudomonal drugs (i.e., tobramycin, cefepime, and piperacillin-tazobactam). Resistance was expressed as a percentage of total isolates as well as the number of carbapenem-resistant bacterial isolates per 10,000 patient days. Pearson correlation was used to assess the relationship between antibiotic use and carbapenem resistance. Following the addition of ertapenem to the formulary, there was a statistically significant decrease in the percentage ofPseudomonas aeruginosaisolates resistant to the group 2 carbapenems (P= 0.003). Group 2 carbapenem use and the number of carbapenem-resistantPseudomonas aeruginosaisolates per 10,000 patient days did not change significantly over the time period. There was a large decrease in the use of ciprofloxacin (P= 0.0033), and there was a correlation of ciprofloxacin use with the percentage of isolates resistant to the group 2 carbapenems (ρ = 0.47,P= 0.002). We suspect that the improvement in susceptibility ofPseudomonas aeruginosato group 2 carbapenems was related to a decrease in ciprofloxacin use.

scholarly journals Emergence and spread of carbapenem-resistant Acinetobacter baumannii in a tertiary care hospital in Turkey

2008 ◽  
Vol 282 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Meliha Meric ◽  
Murat Kasap ◽  
Gulcin Gacar ◽  
Fatma Budak ◽  
Devrim Dundar ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Care Hospital ◽  
Carbapenem Resistant
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