Emergence of Carbapenem Resistance inAcinetobacter baumanniiRecovered From Blood Cultures in Australia

2006 ◽  
Vol 27 (7) ◽  
pp. 759-761 ◽  
Author(s):  
Anton Y. Peleg ◽  
Clare Franklin ◽  
Jan M. Bell ◽  
Denis W. Spelman

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.

2017 ◽  
pp. 52-57
Author(s):  
Nu Xuan Thanh Le ◽  
Thi Anh Ngoc Le ◽  
Thi Nam Lien Nguyen ◽  
Viet Quynh Tram Ngo ◽  
Santona Antonella ◽  
...  

Background: Today carbapenem-resistant A. baumannii isolates are rising in several parts of the world including Vietnam, they are recognized to be among the most difficult resistant bacteria to treat and control. Carbapenem resistance is most commonly caused by the production of OXA-type carbapenemases and metallo-β-lactamases (MBLs). Objectives: Determine the rate and detect the genes encoding acquired carbapenemase of carbapenem-resistant A. baumannii isolates. Materials and methods: Study design is cross-sectional descriptive study. Carbapenem-resistant A. baumannii isolates in 90 A. baumannii (ACB) complex isolates were collected from Hue Central Hospital (HCH) and Hue University Hospital (HUP). Susceptibility to carbapenem of A. baumannii strains were performed by MicroScan method. Multiplex PCRs were performed to detect the genes encoding acquired carbapenemase. Results: Carbapenem resistance rates in A. baumannii were 88.5% and 87.5% in HCH and HHUMP, respectively. All of genes blaOXA-51, blaOXA-23, blaOXA-58, blaIMP, blaNDM as well as coexistence of two genes (blaIMP, blaNDM) or three genes ((blaOXA-51, blaOXA-23, blaOXA-58) or (blaIMP, blaNDM, blaOXA-58)) were detected in carbapenem resistant A. baumannii isolates. Conclusions: Carbapenem resistance rate in A. baumannii was relatively high. The emergence of carbapenem resistance in A. baumannii is associated with the production of OXA-type carbapenemases and metallo-β-lactamases (MBLs). Key words: Acinetobacter baumannii; carbapenem resistance; carbapenemase


Author(s):  
Rabia Arshad

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.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elvira Garza-González ◽  
Paola Bocanegra-Ibarias ◽  
Eduardo Rodríguez-Noriega ◽  
Esteban González-Díaz ◽  
Jesús Silva-Sanchez ◽  
...  

Abstract Background This study aimed to determine the epidemiological, microbiological, and molecular characteristics of an outbreak of carbapenem-resistant Leclercia adecarboxylata in three hospitals associated with the unintended use of contaminated total parental nutrition (TPN). Methods For 10 days, 25 patients who received intravenous TPN from the same batch of a formula developed sepsis and had blood cultures positive for L. adecarboxylata. Antimicrobial susceptibility and carbapenemase production were performed in 31 isolates, including one from an unopened bottle of TPN. Carbapenemase-encoding genes, extended-spectrum β-lactamase–encoding genes were screened by PCR, and plasmid profiles were determined. Horizontal transfer of carbapenem resistance was performed by solid mating. Clonal diversity was performed by pulsed-field gel electrophoresis. The resistome was explored by whole-genome sequencing on two selected strains, and comparative genomics was performed using Roary. Results All 31 isolates were resistant to aztreonam, cephalosporins, carbapenems, trimethoprim/sulfamethoxazole, and susceptible to gentamicin, tetracycline, and colistin. Lower susceptibility to levofloxacin (51.6%) and ciprofloxacin (22.6%) was observed. All the isolates were carbapenemase producers and positive for blaNDM-1, blaTEM-1B, and blaSHV-12 genes. One main lineage was detected (clone A, 83.9%; A1, 12.9%; A2, 3.2%). The blaNDM-1 gene is embedded in a Tn125-like element. Genome analysis showed genes encoding resistance for aminoglycosides, quinolones, trimethoprim, colistin, phenicols, and sulphonamides and the presence of IncFII (Yp), IncHI2, and IncHI2A incompatibility groups. Comparative genomics showed a major phylogenetic relationship among L. adecarboxylata I1 and USDA-ARS-USMARC-60222 genomes, followed by our two selected strains. Conclusion We present epidemiological, microbiological, and molecular evidence of an outbreak of carbapenem-resistant L. adecarboxylata in three hospitals in western Mexico associated with the use of contaminated TPN.


2021 ◽  
Vol 71 (11) ◽  
pp. 2576-2581
Author(s):  
Saima Ishtiaq ◽  
Sidrah Saleem ◽  
Abdul Waheed ◽  
Arslan Ahmed Alvi

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...


2020 ◽  
Author(s):  
Reem M Hassan ◽  
Sherifa T Salem ◽  
Saly Ismail Mostafa Hassan ◽  
Asmaa Sayed Hegab ◽  
Yasmine S Elkholy

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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Amit Sharma ◽  
Rajni Gaind

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.


2006 ◽  
Vol 50 (9) ◽  
pp. 2941-2945 ◽  
Author(s):  
Karen Lolans ◽  
Thomas W. Rice ◽  
L. Silvia Munoz-Price ◽  
John P. Quinn

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Garima Bansal ◽  
Rachelle Allen-McFarlane ◽  
Broderick Eribo

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.


mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Masoumeh Douraghi ◽  
Johanna J. Kenyon ◽  
Parisa Aris ◽  
Mahla Asadian ◽  
Sedighe Ghourchian ◽  
...  

ABSTRACT The worldwide distribution of carbapenem-resistant Acinetobacter baumannii (CRAB) has become a global concern, particularly in countries where antibiotic prescription is not tightly regulated. However, knowledge of the genomic aspects of CRAB from many parts of the world is still limited. Here, 50 carbapenem-resistant A. baumannii isolates recovered at a single hospital in Tehran, Iran, during several outbreaks in 2012 and 2013 were found to be resistant to multiple antibiotics. They were examined using PCR mapping and multilocus sequence typing (MLST). All Iranian strains belonged to sequence type 328 in the Institut Pasteur MLST scheme (ST328IP), a single-locus variant of ST81IP, and all Iranian strains contained two carbapenem resistance genes, oxa23 and oxa24. The oxa23 gene is in the transposon Tn2006 in AbaR4, which interrupts the chromosomal comM gene. Phylogenetic analysis using whole-genome sequence (WGS) data for 9 isolates showed that they belonged to the same clade, designated the ST81/ST328 clade, within lineage 2 of global clone 1 (GC1). However, there were two groups that included either KL13 or KL18 at the K locus (KL) for capsular polysaccharide synthesis and either a tet39 or an aadB resistance gene, respectively. The genetic context of the resistance genes was determined, and the oxa24 (OXA-72 variant) and tet39 (tetracycline resistance) genes were each in a pdif module in different plasmids. The aadB gene cassette (which encodes gentamicin, kanamycin, and tobramycin resistance) was harbored by pRAY*, and the aphA6 gene (which encodes amikacin resistance) and sul2 gene (which encodes sulfamethoxazole resistance) were each harbored by a different plasmid. The sequences obtained here will underpin future studies of GC1 CRAB strains from the Middle East region. IMPORTANCE Carbapenem-resistant Acinetobacter baumannii strains are among the most critical antibiotic-resistant bacteria causing hospital-acquired infections and treatment failures. The global spread of two clones has been responsible for the bulk of the resistance, in particular, carbapenem resistance. However, there is a substantial gap in our knowledge of which clones and which specific lineages within each clone are circulating in many parts of the world, including Africa and the Middle East region. This is the first genomic analysis of carbapenem-resistant A. baumannii strains from Iran. All the isolates, from a single hospital, belonged to lineage 2 of global clone 1 (GC1) but fell into two groups distinguished by genes in the locus for capsule biosynthesis. The analysis suggests a potential origin of multiply antibiotic-resistant lineage 2 in the Middle East region and highlights the ongoing evolution of carbapenem-resistant GC1 A. baumannii strains. It will enhance future studies on the local and global GC1 population structure.


2012 ◽  
Vol 68 (5) ◽  
pp. 1000-1006 ◽  
Author(s):  
Justas Povilonis ◽  
Vaida Šeputienė ◽  
Renatas Krasauskas ◽  
Raminta Juškaitė ◽  
Monika Miškinytė ◽  
...  

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