Effect of carbapenem consumption patterns on the molecular epidemiology and carbapenem resistance of Acinetobacter baumannii

This study investigated the molecular epidemiology of Acinetobacter baumannii in the University of Debrecen in relation to antibiotic consumption. Overall and ward-specific antibiotic consumption was measured by the number of defined daily doses (DDD) per 100 bed-days between 2002 and 2012. Consumption was analysed against the number of A. baumannii positive patients per 100 bed-days, number of isolates per positive sample, and proportion of carbapenem resistant A. baumannii, using time-series analysis. Altogether 160 A. baumannii isolates from different wards were collected and analysed. Carbapenemase genes blaOXA-23-like , blaOXA-24-like , blaOXA-48-like , blaOXA-51-like , blaOXA-58-like and integrons were sought by PCR. Relatedness of isolates was assessed by PFGE. Prevalence and carbapenem resistance of A. baumannii were statistically associated with carbapenem consumption. Prevalence data followed carbapenem usage with three quarterly lags (r = 0.51–0.53, P<0.001), and meropenem and ertapenem, but not imipenem usage, affected prevalence. Colistin usage, in turn, lagged behind prevalence with one lag (r = 0.68–0.70, P<0.001). Six clusters were identified; the neurology ward with the lowest carbapenem consumption was associated with the carbapenem-susceptible cluster, as well as with the carbapenem-susceptible isolates in the cluster with variable susceptibility. Wards with high carbapenem usage almost exclusively harboured isolates from carbapenem-resistant clusters. All clusters were dominated by isolates of one or two wards, but most wards were represented in multiple clusters. Increases in prevalence and carbapenem resistance of A. baumannii were associated with usage of meropenem and ertapenem but not of imipenem, which led to the spread of multiple clones in the University.

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Diversity of sequence types and impact of fitness cost among carbapenem-resistant Acinetobacter baumannii isolates from Tripoli, Libya

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00277-21 ◽

2021 ◽

Author(s):

Antoine G. Abou Fayad ◽

Louis-Patrick Haraoui ◽

Ahmad Sleiman ◽

Mohamad Jaafar ◽

Abdulaziz Zorgani ◽

...

Keyword(s):

Molecular Epidemiology ◽

Acinetobacter Baumannii ◽

Doubling Time ◽

Core Genome ◽

Carbapenem Resistance ◽

Relative Fitness ◽

Fitness Advantage ◽

Carbapenem Resistant ◽

Sequence Types ◽

Hospital Transmission

We investigated the molecular epidemiology of 21 carbapenem-resistant A. baumannii from Libya, and assessed their relative fitness. Core-genome MLST revealed five inter-hospital transmission clusters. Three clusters were associated with the international clones (IC) IC1, IC2, and IC7. Carbapenem-resistance was associated with bla OXA-23, bla GES-11 , or bla NDM-1 . Compared to A. baumannii DSM 30008, the doubling time was similar over 10 hours, but after 16 hours, half the isolates grew to higher densities, suggesting a fitness advantage.

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Molecular dissection of Carbapenem-resistant Acinetobacter baumannii circulating in Indian hospitals using Whole Genome Sequencing

10.1101/2021.07.30.454432 ◽

2021 ◽

Author(s):

Steffimol Rose ◽

Varun Shamanna ◽

Anthony Underwood ◽

Geetha Nagaraj ◽

Akshatha Prasanna ◽

...

Keyword(s):

Molecular Epidemiology ◽

Whole Genome Sequencing ◽

Acinetobacter Baumannii ◽

Genome Sequencing ◽

Clonal Complex ◽

Carbapenem Resistance ◽

Evolutionary Divergence ◽

Whole Genome ◽

Northern India ◽

Carbapenem Resistant

Objectives: Carbapenem-resistant Acinetobacter baumannii (CRAB) has acquired worldwide recognition as a serious nosocomial infection. It poses a concern to hospitalized patients because of the limited therapeutic options available. Thus, we investigated the molecular epidemiology and antibiotic resistance profiles of A. baumannii isolates in India. Materials and Methods: We characterized 306 retrospective A. baumannii clinical isolates collected from 18 centers across 10 states and 1 Union Territory of India between 2015 and 2019. Molecular epidemiology, and carbapenem resistance were studied by Whole Genome Sequencing. Results: A total of 105 different Sequence Types (STs) were identified including 48 reported STs and 57 Novel STs. 99 isolates were classified into Clonal Complex 451 (CC451) among which ST848 and ST1956 were the common STs. Carbapenemase resistance was confirmed in all the isolates with the presence of intrinsic bla OXA -51-like genes, and the acquired bla OXA-23 and bla NDM-1 genes. Conclusion: Most of the isolates were grouped under clonal complex 451. ST1053 caused an outbreak in Northern India during 2018 and 2019. Novel MLST alleles and STs were also detected, underlining an evolutionary divergence in India. The carbapenem-resistance was dominated by OXA-type carbapenemases and further surveillance of these carbapenem-resistant A. baumannii and antimicrobial stewardship should be strengthened.

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PREVALENCE OF CARBAPENEM-RESISTANT ACINETOBACTER BAUMANNII (CRAB) IN MEDICAL AND SURGICAL INTENSIVE CARE UNITS (ICUS) OF JPMC, KARACHI

Pakistan Journal of Medicine and Dentistry ◽

10.36283/pjmd8-4/006 ◽

2019 ◽

Author(s):

Rabia Arshad

Keyword(s):

Intensive Care ◽

Antimicrobial Resistance ◽

Acinetobacter Baumannii ◽

Intensive Care Units ◽

Carbapenem Resistance ◽

Chronic Obstructive ◽

Surgical Intensive Care ◽

Carbapenem Resistant ◽

Number Of Patients ◽

Increased Risk

Background: Antimicrobial resistance is one of the research priorities of health organizations due to increased risk of morbidity and mortality. Outbreaks of nosocomial infections caused by carbapenem-resistant Acinetobacter Baumannii (CRAB) strains are at rise worldwide. Antimicrobial resistance to carbapenems reduces clinical therapeutic choices and frequently led to treatment failure. The aim of our study was to determine the prevalence of carbapenem resistance in A. baumannii isolated from patients in intensive care units (ICUs). Methods: This cross-sectional study was carried out in the Department of Microbiology, Basic Medical Sciences Institute (BMSI), Jinnah Postgraduate Medical Centre (JPMC), Karachi, from December 2016 to November 2017. Total 63 non-repetitive A. baumannii were collected from the patients’ specimens, admitted to medical and surgical ICUs and wards of JPMC, Karachi. The bacterial isolates were processed according to standard microbiological procedures to observe for carbapenem resistance. SPSS 21 was used for data analysis. Results: Out of the 63 patients, 40 (63.5%) were male. The age of the patient ranged from 15-85 year, with average of 43 year. 34.9% patients had been hospitalized for 3 days. Chronic obstructive pulmonary disease was present in highest number with average of 58.7% for morbidity. Number of patients on mechanical ventilation was highest (65.1%). All isolates were susceptible to colistin. The resistance to ampicillin-sulbactam, ceftazidime, ciprofloxacin, amikacin, piperacillin- tazobactam and meropenem was 82.5%, 81%, 100%, 87.3%, 82.5% and 82% respectively. Out of 82% CRAB, 77% were obtained from ICUs. Conclusion: This study has revealed the high rate of carbapenem resistance in A. baumannii isolates in ICUs thus leaving behind limited therapeutic options.

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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

Journal of the Pakistan Medical Association ◽

10.47391/jpma.01537 ◽

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...

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Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates from Egyptian Patients

10.1101/2020.08.24.264911 ◽

2020 ◽

Author(s):

Reem M Hassan ◽

Sherifa T Salem ◽

Saly Ismail Mostafa Hassan ◽

Asmaa Sayed Hegab ◽

Yasmine S Elkholy

Keyword(s):

Acinetobacter Baumannii ◽

Molecular Characterization ◽

Antimicrobial Agents ◽

Treatment Options ◽

Carbapenem Resistance ◽

Clinical Isolates ◽

Common Mechanism ◽

Carbapenem Resistant ◽

Egyptian Patients ◽

Global Threat

AbstractAcinetobacter baumannii (A. baumannii) represents a global threat owing to its ability to resist most of the currently available antimicrobial agents. Moreover, emergence of carbapenem resistant A. baumannii (CR-AB) isolates limits the available treatment options. Enzymatic degradation by variety of ß-lactamases, have been identified as the most common mechanism of carbapenem resistance in A. baumannii. The alarming increase in the prevalence of CR-AB necessitates continuous screening and molecular characterization to appreciate the problem. The present study was performed to assess the prevalence and characterize carbapenemases among 206 CR-AB isolated from various clinical specimens collected from different intensive care units at Kasr Al-Aini Hospital.All isolates were confirmed to be A. baumannii by detection of the blaOXA-51-like gene. Molecular screening of 13 common Ambler class bla carbapenemases genes in addition to insertion sequence (IS-1) upstream OXA-23 was performed by using four sets of multiplex PCR, followed by identification using gene sequencing technology. Among the investigated genes, the prevalence of blaOXA-23, and blaOXA-58 were 77.7%, and 1.9%, respectively. The ISAba1 was detected in 10% of the blaOXA-23 positive isolates. The prevalence of metallo-β-lactamases (MBLs) studied; blaNDM-1, blaSPM, blaVIM, blaSIM-1 were 11.7%, 6.3%, 0.5%, and 0.5% respectively. One of class A; bla KPC was detected in 10.7% of the investigated isolates. blaOXA-24/40, blaIMP, blaGES, blaVEB and blaGIM were not detected in any of the studied isolates. Moreover, 18.4% of the isolates have shown to harbor two or more of the screened bla genes. We concluded that the most prevalent type of ß-lactamases genes among CR-AB isolates collected from Egyptian patients were blaOXA-23 followed by blaNDM-1 and blaKPC.Author summaryCarbapenem-resistant A. baumannii has become a real global health threat. The aim of the present study was to characterize and to assess the prevalence of carbapenemases among 206 CR-AB clinical isolates from Egyptian patients. We concluded that the most prevalent type of ß-lactamases genes among CR-AB isolates collected from Egyptian patients were blaOXA-23 followed by blaNDM-1 and blaKPC. In this study, ISAba1 was detected upstream 10% of blaOXA-23 positive isolates only which indicates that the spread of resistance among Acinetobacter isolates could be either chromosomal or plamid-mediated.

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Risk-adjusted antibiotic consumption in 34 public acute hospitals in Ireland, 2006 to 2014

Eurosurveillance ◽

10.2807/1560-7917.es.2016.21.32.30312 ◽

2016 ◽

Vol 21 (32) ◽

Cited By ~ 1

Author(s):

Ajay Oza ◽

Fionnuala Donohue ◽

Howard Johnson ◽

Robert Cunney

Keyword(s):

Administrative Data ◽

Risk Adjustment ◽

Antibiotic Consumption ◽

Factors Affecting ◽

Defined Daily Doses ◽

Acute Hospitals ◽

Consumption Rates ◽

Hospital Antibiotic Consumption ◽

Bed Days ◽

The Impact

As antibiotic consumption rates between hospitals can vary depending on the characteristics of the patients treated, risk-adjustment that compensates for the patient-based variation is required to assess the impact of any stewardship measures. The aim of this study was to investigate the usefulness of patient-based administrative data variables for adjusting aggregate hospital antibiotic consumption rates. Data on total inpatient antibiotics and six broad subclasses were sourced from 34 acute hospitals from 2006 to 2014. Aggregate annual patient administration data were divided into explanatory variables, including major diagnostic categories, for each hospital. Multivariable regression models were used to identify factors affecting antibiotic consumption. Coefficient of variation of the root mean squared errors (CV-RMSE) for the total antibiotic usage model was very good (11%), however, the value for two of the models was poor (> 30%). The overall inpatient antibiotic consumption increased from 82.5 defined daily doses (DDD)/100 bed-days used in 2006 to 89.2 DDD/100 bed-days used in 2014; the increase was not significant after risk-adjustment. During the same period, consumption of carbapenems increased significantly, while usage of fluoroquinolones decreased. In conclusion, patient-based administrative data variables are useful for adjusting hospital antibiotic consumption rates, although additional variables should also be employed.

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Development of Loop-Mediated Isothermal Amplification Assay for Detection of Clinically Significant Members of Acinetobacter calcoaceticus–baumannii Complex and Associated Carbapenem Resistance

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.659256 ◽

2021 ◽

Vol 8 ◽

Author(s):

Amit Sharma ◽

Rajni Gaind

Keyword(s):

Acinetobacter Baumannii ◽

Lamp Assay ◽

Carbapenem Resistance ◽

Acinetobacter Calcoaceticus ◽

Isothermal Amplification ◽

Colony Count ◽

Dna Concentration ◽

Loop Mediated Isothermal Amplification ◽

Carbapenem Resistant ◽

Clinically Significant

Background:Acinetobacter calcoaceticus–baumannii (ACB) complex has emerged as an important nosocomial pathogen and is associated with life-threatening infections, especially among ICU patients, including neonates. Carbapenem resistance in Acinetobacter baumannii has emerged globally and is commonly mediated by blaOXA-23. Clinically significant infections with carbapenem-resistant Acinetobacter baumannii (CRAB) are a major concern since therapeutic options are limited and associated mortality is high. Early diagnosis of both the pathogen and resistance is important to initiate the optimal therapy and prevent selection of resistance. In the current study, a loop-mediated isothermal amplification (LAMP) assay was developed for rapid detection of the ACB complex and carbapenem resistance mediated by blaOXA-23.Methodology: Universal LAMP primers were designed for the detection of significant members of the ACB complex and carbapenem resistance targeting the ITS 16S–23S rRNA and blaOXA-23 gene respectively. The optimal conditions for the LAMP assay were standardized for each primer set using standard ATCC strains. The sensitivity of the LAMP assay was assessed based on the limit of detection (LOD) using different DNA concentrations and colony counts. The specificity of LAMP was determined using the non-ACB complex and non-Acinetobacter species. The results of the LAMP assay were compared with those of polymerase chain reaction (PCR).Results: The optimal temperature for the LAMP assay was 65°C, and the detection time varied with various primers designed. Using the ITS Ab1 primer, LODs of LAMP and PCR assays were 100 pg/μl and 1 ng/μl of DNA concentration and 104 cfu/ml and 108 cfu/ml of colony count, respectively. The LAMP assay was 10- and 104-fold more sensitive than PCR using DNA concentration and colony count, respectively. The LAMP assay was found to be specific for clinically important ACB complex species.Significance of the study: The LAMP assay can be applied for early detection of significant species of the ACB complex from clinical samples and their carbapenem-resistant variants. Depending on the emerging pathogen and locally prevalent resistance genes, the LAMP assay can be modified for detection of colonization or infection by various resistant bugs.

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Emergence of Carbapenem Resistance inAcinetobacter baumanniiRecovered From Blood Cultures in Australia

Infection Control and Hospital Epidemiology ◽

10.1086/507012 ◽

2006 ◽

Vol 27 (7) ◽

pp. 759-761 ◽

Cited By ~ 27

Author(s):

Anton Y. Peleg ◽

Clare Franklin ◽

Jan M. Bell ◽

Denis W. Spelman

Keyword(s):

Acinetobacter Baumannii ◽

Linear Trend ◽

Carbapenem Resistance ◽

Blood Cultures ◽

Clonal Type ◽

Carbapenem Resistant ◽

Genes Encoding ◽

Blood Specimens

We describe the first emergence of carbapenem-resistantAcinetobacter baumanniiin Australia. NinetyA. baumanniiisolates recovered from cultures of blood specimens from 69 patients were analyzed. Overall, 58 isolates (64%) were resistant to meropenem. The χ2test for linear trend revealed that emergence of carbapenem resistance was statistically significant during the 32-month study period. Selected isolates were of the same clonal type, and no genes encoding carbapenemases were identified.

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Multicity Outbreak of Carbapenem-Resistant Acinetobacter baumannii Isolates Producing the Carbapenemase OXA-40

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00116-06 ◽

2006 ◽

Vol 50 (9) ◽

pp. 2941-2945 ◽

Cited By ~ 127

Author(s):

Karen Lolans ◽

Thomas W. Rice ◽

L. Silvia Munoz-Price ◽

John P. Quinn

Keyword(s):

Acinetobacter Baumannii ◽

Carbapenem Resistance ◽

The United States ◽

Nucleotide Sequencing ◽

Sequencing Analysis ◽

Carbapenem Resistant ◽

Extended Care ◽

Care Facilities ◽

High Level ◽

First Time

ABSTRACT During 2005 we detected a multicity outbreak of infections or colonization due to high-level imipenem-resistant Acinetobacter baumannii (MIC, 64 μg/ml). One hundred isolates from diverse sources were obtained from seven acute-care hospitals and two extended-care facilities; 97% of the isolates belonged to one clone. Susceptibility testing of the first 42 isolates (January to April 2005) revealed broad resistance profiles. Half of the isolates were susceptible to ceftazidime, with many isolates susceptible only to colistin. The level of AmpC β-lactamase expression was stronger in isolates resistant to ceftazidime. PCR and subsequent nucleotide sequencing analysis identified bla OXA-40. The presence of an OXA-40 β-lactamase in these isolates correlated with the carbapenem resistance. By Southern blot analysis, a bla OXA-40-specific probe revealed that the gene was both plasmid and chromosomally located. This is the first time in the United States that such carbapenem resistance in A. baumannii has been attributable to a carbapenemase.

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Antibiotic Susceptibility, Clonality, and Molecular Characterization of Carbapenem-Resistant Clinical Isolates of Acinetobacter baumannii from Washington DC

International Journal of Microbiology ◽

10.1155/2020/2120159 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Garima Bansal ◽

Rachelle Allen-McFarlane ◽

Broderick Eribo

Keyword(s):

Acinetobacter Baumannii ◽

Multiplex Pcr ◽

Antibiotic Susceptibility ◽

Carbapenem Resistance ◽

The United States ◽

Pcr Analysis ◽

Washington Dc ◽

Antibiotic Resistant ◽

Group 4 ◽

Carbapenem Resistant

The occurrence of carbapenem-resistant (CR) strains of Acinetobacter baumannii is reported to contribute to the severity of several nosocomial infections, especially in critically ill patients in intensive care units. The present study aims to determine the antibiotic susceptibility, clonality, and genetic mechanism of carbapenem resistance in twenty-eight Acinetobacter baumannii isolates from four hospitals in Washington DC. The antibiotic susceptibility of the isolates was determined by VITEK 2 analyses, while PCR was used to examine the presence of antibiotic-resistant genes and mobile genetic elements. Trilocus multiplex-PCR was used along with pulsed-field gel electrophoresis (PFGE) for strain typing and for accessing clonal relationships among the isolates. Antimicrobial susceptibility testing indicated that 46% of the isolates were carbapenem-resistant and possessed MDR and XDR phenotypes. PFGE clustered the 28 isolates into seven clonal (C1–C7) complexes based on >75% similarity cut-off. Thirty-six percent of the isolates belonged to international clone II, while 29% were assigned to Group 4 by trilocus multiplex-PCR. Although the blaOXA-51-like gene was found in all the isolates, only 36% were positive for the blaOXA-23-like gene. PCR analysis also found a metallo-β-lactamase (MBL) gene (blaVIM) in 71% of the isolates. Of the 13 CR isolates, 8 were PCR positive for both blaVIM and blaOXA-23-like genes, while 5 harbored only blaVIM gene. This study revealed the emergence of VIM carbapenemase-producing A. baumannii isolates, which has not been previously reported in the United States.

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