scholarly journals Sequence types of Portuguese carbapenem-resistant Acinetobacter baumannii isolates collected over 10 years

2010 ◽  
Vol 65 (10) ◽  
pp. 2254-2256 ◽  
Author(s):  
G. J. Da Silva ◽  
N. Mendonca ◽  
G. Batista ◽  
A. Duarte
Keyword(s):  
Acinetobacter Baumannii ◽  
Carbapenem Resistant ◽  
Sequence Types

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

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.

scholarly journals Diversity of Oxacillinases and Sequence Types in Carbapenem-Resistant Acinetobacter baumannii from Austria

2021 ◽  
Vol 18 (4) ◽  
pp. 2171 ◽  
Author(s):  
Andrea Grisold ◽  
Josefa Luxner ◽  
Branka Bedenić ◽  
Magda Diab-Elschahawi ◽  
Michael Berktold ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Genetic Background ◽  
Regional Differences ◽  
Carbapenem Resistance ◽  
Carbapenem Resistant ◽  
Class D ◽  
Acinetobacter Spp ◽  
First Time ◽  
Sequence Types ◽  
Significant Health

Carbapenem-resistant Acinetobacter baumannii is a significant health problem worldwide. A multicenter study on A. baumannii was performed to investigate the molecular epidemiology and genetic background of carbapenem resistance of A. baumannii isolates collected from 2014–2017 in Austria. In total, 117 non-repetitive Acinetobacter spp. assigned to A. baumannii (n = 114) and A. pittii (n = 3) were collected from four centers in Austria. The isolates were uniformly resistant to piperacillin/tazobactam, ceftazidime, and carbapenems, and resistance to imipenem and meropenem was 97.4% and 98.2%, respectively. The most prominent OXA-types were OXA-58-like (46.5%) and OXA-23-like (41.2%), followed by OXA-24-like (10.5%), with notable regional differences. Carbapenem-hydrolyzing class D carbapenemases (CHDLs) were the only carbapenemases found in A.baumannii isolates in Austria since no metallo-β-lactamases (MBLs) nor KPC or GES carbapenemases were detected in any of the isolates. One-third of the isolates harbored multiple CHDLs. The population structure of A. baumannii isolates from Austria was found to be very diverse, while a total of twenty-three different sequence types (STs) were identified. The most frequent was ST195 found in 15.8%, followed by ST218 and ST231 equally found in 11.4% of isolates. Two new ST types, ST2025 and ST2026, were detected. In one A. pittii isolate, blaOXA-143-like was detected for the first time in Austria.

scholarly journals Subtypes, resistance and virulence platforms in extended-drug resistant Acinetobacter baumannii Romanian isolates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irina Gheorghe ◽  
Ilda Czobor Barbu ◽  
Marius Surleac ◽  
Ionela Sârbu ◽  
Laura Ioana Popa ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Carbapenem Resistance ◽  
Control Measures ◽  
Drug Resistant ◽  
Infection Control Measures ◽  
Carbapenem Resistant ◽  
Ambulatory Patients ◽  
Severe Infections ◽  
Healthcare Associated ◽  
Sequence Types

AbstractAcinetobacter baumannii has emerged worldwide as a dominant pathogen in a broad range of severe infections, raising an acute need for efficient antibacterials. This is the first report on the resistome and virulome of 33 extended drug-resistant and carbapenem-resistant A. baumannii (XDR CRAB) strains isolated from hospitalized and ambulatory patients in Bucharest, Romania. A total of 33 isolates were collected and analyzed using phenotypic antibiotic susceptibility and conjugation assays, PCR, whole-genome sequencing (WGS), pulsed-field gel electrophoresis (PFGE) and MultiLocus Sequence Typing (MLST). All isolates were extensively drug-resistant (XDR), being susceptible only to colistin. The carbapenem resistance was attributed by PCR mainly to blaOXA-24 and blaOXA-23 genes. PFGE followed by MLST analysis demonstrated the presence of nine pulsotypes and six sequence types. WGS of seven XDR CRAB isolates from healthcare-associated infections demonstrated the high diversity of resistance genes repertoire, as well as of mobile genetic elements, carrying ARGs for aminoglycosides, sulphonamides and macrolides. Our data will facilitate the understanding of resistance, virulence and transmission features of XDR AB isolates from Romanian patients and might be able to contribute to the implementation of appropriate infection control measures and to develop new molecules with innovative mechanisms of action, able to fight effectively against these bugs, for limiting the spread and decreasing the infection rate and mortality.

Investigation of carbapenem resistant Acinetobacter baumannii ST2 in Iran

2020 ◽  
Author(s):  
Aliakbar Rezaei ◽  
Hossein Fazeli ◽  
Jamshid Faghri
Keyword(s):  
Acinetobacter Baumannii ◽  
Clonal Complex ◽  
Carbapenem Resistance ◽  
Diffusion Method ◽  
Disc Diffusion Method ◽  
Carbapenem Resistant ◽  
Rapd Pcr ◽  
Relationship Of ◽  
Sequence Types ◽  
Respiratory Specimens

AbstractThis study investigated carbapenem resistance among Acinetobacter baumannii isolated from respiratory specimens. Epidemiological relationship of the isolates was also evaluated. In this study, 81 respiratory specimens of A. baumannii from AL Zahra Hospital were confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was performed by disc diffusion method. Carbapenem resistance genes were identified by PCR. The isolates were typed by RAPD-PCR and multilocus sequence typing (MLST) methods. All isolates were resistant to imipenem and 80 isolates to meropenem. Frequency of oxacillinase genes was as follows: blaOXA-23 gene was positive in 74 (91.3%), blaOXA-24 gene in 50 (61.7%) and blaOXA-58 was not found in any isolates. On the other hand 22 (27.2%) isolates contained blaIMP-1, 3 (3.7%) isolates contained blaIMP-2 gene, 5 (6.2%) isolates contained blaVIM-1, 4 (5%) isolates had blaVIM-2 and none of the isolates had blaSIM-1 gene. RAPD-PCR typing identified 16 different patterns, with one pattern being the most frequent one in 26 isolates. In MLST 6 different sequence types were identified, the most predominant being ST2 belonging to clonal complex 2. The results of this study showed high resistance to carbapenems as well as high abundance of oxacillinase genes.

scholarly journals Molecular Epidemiology of Carbapenem-Resistant Acinetobacter baumannii Isolated from War-Injured Patients from the Eastern Ukraine

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 579
Author(s):  
Paul G. Higgins ◽  
Ralf Matthias Hagen ◽  
Andreas Podbielski ◽  
Hagen Frickmann ◽  
Philipp Warnke
Keyword(s):  
Acinetobacter Baumannii ◽  
Core Genome ◽  
Acquired Resistance ◽  
Sequence Type ◽  
Carbapenem Resistant ◽  
Next Generation Sequencing Ngs ◽  
Injured Patients ◽  
Sequence Types ◽  
Generation Sequencing ◽  
Epidemiological Information

Recently, a total of 32 carbapenem- and fluoroquinolone-resistant Acinetobacter baumannii (Ab) isolates was isolated from war-injured patients who were treated at German Bundeswehr Hospitals, and preliminarily typed by “DiversiLab” repetitive elements sequence-based (rep-) PCR. Core genome-based sequence typing was also used to provide more detailed epidemiological information. From the clusters observed by rep-PCR, selected Ab strains were subjected to Next Generation Sequencing (NGS) in order to compare them with international outbreak-associated Ab strains and to identify MLST (multi-locus sequence type) lineages, as well as to identify known resistance genes. Accordingly, NGS indicated higher diversity than rep-PCR, but also confirmed likely transmission events. The identified acquired carbapenem-resistant genes comprised blaOXA-23, blaOXA-72 and blaGES-12, as well as various other intrinsic and acquired resistance-associated genetic elements. All isolates clustered with the previously identified international clonal lineages IC1, IC2, IC6 and IC7, with corresponding Pasteur sequence types ST1, ST2, ST78 and ST25, respectively. In conclusion, the assessment confirmed a broad spectrum of resistance-associated genes in Ab isolated from war-injured patients from the Eastern Ukraine, and provided the first insights into locally abundant clonal lineages.

scholarly journals The Role of Uniform Meropenem Usage in Acinetobacter baumannii Clone Replacement

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 127
Author(s):  
Bence Balázs ◽  
Zoltán Tóth ◽  
Fruzsina Nagy ◽  
Renátó Kovács ◽  
Hajnalka Tóth ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Care Center ◽  
Tertiary Care ◽  
Antibiotic Consumption ◽  
Resistance Level ◽  
Carbapenem Resistant ◽  
Significant Difference ◽  
Time Kill ◽  
Sequence Types

The dominant carbapenem resistant Acinetobacter baumannii harboring blaOXA-23-like carbapenemase was replaced by blaOXA-40-like carriers in a Hungarian tertiary-care center with high meropenem but relatively low imipenem use. We hypothesized that alterations in antibiotic consumption may have contributed to this switch. Our workgroup previous study examined the relation between resistance spiral and the antibiotic consumption, and the results suggest that the antibiotic usage provoked the increasing resistance in case of A. baumannii. We aimed at measuring the activity of imipenem and meropenem to compare the selection pressure exerted by the different carbapenems in time-kill assays. Strain replacement was confirmed by whole genome sequencing, core-genome multilocus sequence typing (cgMLST), and resistome analysis. Based on results of the time-kill assays, we found a significant difference between two different sequence-types (STs) in case of meropenem, but not in case of imipenem susceptibility. The newly emerged ST636 and ST492 had increased resistance level against meropenem compared to the previously dominant ST2 and ST49. On the other hand, the imipenem and colistin resistance profiles were similar. These results suggest, that the uniform meropenem usage may have contributed to A. baumannii strain replacement in our setting.

scholarly journals Characterization of carbapenem-resistant hypervirulent Acinetobacter baumannii strains isolated from hospitalized patients in the mid-south region of China

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jun Li ◽  
Ting Yu ◽  
Yi Luo ◽  
Jing-Yi Peng ◽  
Yu-Jia Li ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Acinetobacter Baumannii ◽  
High Mortality ◽  
Galleria Mellonella ◽  
Opportunistic Pathogen ◽  
Infection Model ◽  
Carbapenem Resistant ◽  
Blood Specimens ◽  
Sequence Types

Abstract Background Acinetobacter baumannii has traditionally been considered an opportunistic pathogen with low virulence. In this study, we characterized the carbapenem-resistant hypervirulent A. baumannii (CR-hvAB) stains isolated from our hospital in mid-south region of China. Results Blood samples collected between January 2017 and May 2019 were used for virulence experiments and biofilm assays of individual carbapenem-resistant A. baumannii (CR-AB) strains, performed using a Galleria mellonella infection model and crystal violet staining method, respectively. CR-AB isolates that induced high mortality in the G. mellonella infection model were subjected to genotyping, susceptibility testing, and clinical data analysis, and the genetic characterization of these isolates was performed by whole-genome sequencing (WGS). Among the 109 CR-AB clinical strains, the survival rate of G. mellonella larvae infected with 7 (6.4%) CR-AB isolates (number of strains with mortality of 0, 10 and 20% was 4, 1, and 2, respectively), was significantly lower than that of A. baumannii ATCC 19606 (100.0%) and the remaining CR-AB isolates (> 80.0%). Consistent with these results, patients infected with these seven isolates had an average 7-day mortality rate of 42.9%, suggesting that the isolates were CR-hvAB. These seven isolates belonged to four sequence types (STs): ST457, ST195, ST369, and ST2088 (a new ST), and mainly ST457 (n = 4). The results of the biofilm study showed that eight strains had powerful biofilm ability (strong [n = 1] and moderate [n = 7] biofilm producers) including these seven CR-hvAB isolates. Conclusions CR-hvAB isolates that induced a high mortality rate were cloned in our hospital, most of which belonged to ST457; thus, monitoring of these strains, particularly ST457, should be strengthened in the future. Meanwhile, A. baumannii, which was isolated from blood specimens and found to powerful biofilm-forming ability, is a probable hvAB isolate.

scholarly journals WGS-Based Analysis of Carbapenem-Resistant Acinetobacter baumannii in Vietnam and Molecular Characterization of Antimicrobial Determinants and MLST in Southeast Asia

Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 563
Author(s):  
Gamal Wareth ◽  
Jörg Linde ◽  
Ngoc H. Nguyen ◽  
Tuan N. M. Nguyen ◽  
Lisa D. Sprague ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Acinetobacter Baumannii ◽  
Core Genome ◽  
Action Plan ◽  
Carbapenem Resistant ◽  
Global Threat ◽  
Next Generation Sequencing Ngs ◽  
Sequence Types ◽  
Generation Sequencing

Carbapenem-resistant Acinetobacter baumannii (A. baumannii, CRAb) is an emerging global threat for healthcare systems, particularly in Southeast Asia. Next-generation sequencing (NGS) technology was employed to map genes associated with antimicrobial resistance (AMR) and to identify multilocus sequence types (MLST). Eleven strains isolated from humans in Vietnam were sequenced, and their AMR genes and MLST were compared to published genomes of strains originating from Southeast Asia, i.e., Thailand (n = 49), Myanmar (n = 38), Malaysia (n = 11), Singapore (n = 4) and Taiwan (n = 1). Ten out of eleven Vietnamese strains were CRAb and were susceptible only to colistin. All strains harbored ant(3”)-IIa, armA, aph(6)-Id and aph(3”) genes conferring resistance to aminoglycosides, and blaOXA-51 variants and blaADC-25 conferring resistance to ß-lactams. More than half of the strains harbored genes that confer resistance to tetracyclines, sulfonamides and macrolides. The strains showed high diversity, where six were assigned to sequence type (ST)/2, and two were allocated to two new STs (ST/1411-1412). MLST analyses of 108 strains from Southeast Asia identified 19 sequence types (ST), and ST/2 was the most prevalent found in 62 strains. A broad range of AMR genes was identified mediating resistance to ß-lactams, including cephalosporins and carbapenems (e.g., blaOXA-51-like, blaOXA-23, blaADC-25, blaADC-73, blaTEM-1, blaNDM-1), aminoglycosides (e.g., ant(3”)-IIa, aph(3”)-Ib, aph(6)-Id, armA and aph(3’)-Ia), phenicoles (e.g., catB8), tetracyclines (e.g., tet.B and tet.39), sulfonamides (e.g., sul.1 and sul.2), macrolides and lincosamide (e.g., mph.E, msr.E and abaF). MLST and core genome MLST (cgMLST) showed an extreme diversity among the strains. Several strains isolated from different countries clustered together by cgMLST; however, different clusters shared the same ST. Developing an action plan on AMR, increasing awareness and prohibiting the selling of antibiotics without prescription must be mandatory for this region. Such efforts are critical for enforcing targeted policies on the rational use of carbapenem compounds and controlling AMR dissemination and emergence in general.

scholarly journals Characterization of Carbapenem-Resistant Acinetobacter baumannii Strains Isolated from Hospitalized Patients in Palestine

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Regeen Handal ◽  
Lulu Qunibi ◽  
Ibrahim Sahouri ◽  
Maha Juhari ◽  
Rula Dawodi ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Virulence Gene ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Single Patient ◽  
Carbapenem Resistant ◽  
Control And Prevention ◽  
Sequence Types

The American Centers for Disease Control and Prevention (CDC) recognizes Acinetobacter baumannii as a source of global outbreaks and epidemics especially due to its increasing resistance to commercially available antibiotics. In this study, 69 single patient multidrug resistant isolates collected from all over Palestine, except Gaza, were studied. All the isolates were resistant to all the β–lactam antibiotics including the carbapenems. Of the 69 isolates, 82.6% were positive for blaOXA-23, 14.5% were positive for blaOXA-24, and 3% were positive for blaOXA-58. None were positive for blaOXA-143 and blaOXA-235. In addition, 5.8% and 0% were positive for blaNDM and blaKPC, respectively. Of the 69 isolates, none were positive for the aminoglycoside aphA6 gene while 93% were positive for the aphA1 gene. The acetyltransferases aacC1 and aacA4 genes tested positive in 22% and 13% of the isolates, respectively. The ompA biofilm-producing virulence gene was detected in all isolates. Finally, Multilocus Sequence Typing (MLST) of 13 isolates revealed that more than one strain of A. baumannii was circulating in Palestinian hospitals as results revealed that 7 isolates were of ST208, 2 isolates ST218, 1 isolate ST231, 1 isolate ST348, and 2 new Sequence Types. The detection of these drug resistant pathogens is a reminder of the importance of active surveillance for resistant bacteria in order to prevent their spread in hospital settings.

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