scholarly journals Occurrence of Diverse AbGRI1-Type Genomic Islands in Acinetobacter baumannii Global Clone 2 Isolates from South Korea

2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Dae Hun Kim ◽  
Sook-In Jung ◽  
Ki Tae Kwon ◽  
Kwan Soo Ko
Keyword(s):  
South Korea ◽  
Acinetobacter Baumannii ◽  
Genomic Island ◽  
Clonal Complex ◽  
Carbapenem Resistance ◽  
Bloodstream Infections ◽  
Housekeeping Genes ◽  
Genomic Islands ◽  
Content Type ◽  
Sequence Types

ABSTRACT In this study, we analyzed the frequency of the AbGRI1-type genomic island (GI) and its association with genotypes. We obtained 130 Acinetobacter baumannii isolates causing bloodstream infections from patients in South Korea. Antimicrobial susceptibility testing and multilocus sequence typing were performed. The presence of AbGRI1-type GIs and their structures were determined by sequential PCR and sequencing. Ninety-eight isolates (75.3%) representing 14 sequence types (STs) belonged to clonal complex 208 (CC208), corresponding to global clone 2 (GC2). AbGRI1-type GIs interrupted the comM gene in 107 isolates (82.4%). Four types of GIs were identified: Tn6022 (50 isolates; 46.7%), AbaR4 (23 isolates; 21.5%), Tn6166 (10 isolates; 9.3%), and Tn6166/Tn2006 (24 isolates; 22.4%). In the 50 isolates with Tn6022, Tn2006 or Tn2008B, both containing ISAba1-bla OXA-23, was present in sites other than GIs in 3 or 28 isolates, respectively. In the 10 isolates with Tn6166, Tn2008B was identified in one isolate. AbGRI1-type GIs were identified nearly exclusively in CC208 isolates, with the exception of nine non-CC208 isolates (AbaR4 in eight ST229 isolates and Tn6022 in one ST1244 isolate). Within CC208 isolates, there was evidence of frequent recombination events, in both housekeeping genes and AbGRI1-type GIs, contributing to genotype diversification and the emergence of carbapenem resistance.

scholarly journals Impact of Carbapenem Resistance and Receipt of Active Antimicrobial Therapy on Clinical Outcomes of Acinetobacter baumannii Bloodstream Infections

2011 ◽  
Vol 55 (10) ◽  
pp. 4844-4849 ◽  
Author(s):  
John S. Esterly ◽  
Milena Griffith ◽  
Chao Qi ◽  
Michael Malczynski ◽  
Michael J. Postelnick ◽  
...  
Keyword(s):  
Hospital Mortality ◽  
Acinetobacter Baumannii ◽  
Antimicrobial Therapy ◽  
Active Agent ◽  
Carbapenem Resistance ◽  
Bloodstream Infections ◽  
Chronically Ill ◽  
Cox Proportional Hazards Model ◽  
Bivariate Analysis ◽  
Content Type

ABSTRACTNosocomialAcinetobacter baumanniibloodstream infections occur with significant prevalence and mortality. The relationship between carbapenem resistance inA. baumanniiand patient outcomes remains unclear. A retrospective cohort study was conducted on patients withA. baumanniibacteremia. Outcomes, controlling for confounders, were compared for carbapenem-nonresistantA. baumannii(CNRAB) and carbapenem-resistantA. baumannii(CRAB). The primary outcome studied was all-cause hospital mortality, and the secondary endpoints evaluated were time to mortality, time to negative cultures, and length of stay postinfection for survivors. A total of 79 patients, 37 infected with CRAB and 42 with CNRAB, were studied. Hospital mortality was greater in the CRAB group as determined based on bivariate analysis (P< 0.01); however, this effect was nullified when controlling for relevant confounders with logistic regression and a Cox proportional-hazards model (P= 0.71 and 0.75, respectively). Values for time to mortality and time to negative cultures did not differ between the groups. The median number of days of stay postinfection for survivors was greater for the CRAB group than the CNRAB group (14 versus 6.5;P< 0.01). Patients who received active antimicrobial therapy were less likely to die (93.5% versus 74.2%;P= 0.02), regardless of carbapenem susceptibility classifications, and this result was robust in the multivariate model (P= 0.02). Trends existed for improved outcomes in patients receiving an active beta-lactam, and patients fared worse if they had received a polymyxin as an active agent. Patients with CRAB bloodstream infections were more chronically ill and had more comorbidities. Inactive therapy was more important than carbapenem susceptibility with respect to outcomes, was a strong predictor of death, and is potentially modifiable.

scholarly journals Salmonella Genomic Island 1B Variant Found in a Sequence Type 117 Avian Pathogenic Escherichia coli Isolate

mSphere ◽  
2019 ◽  
Vol 4 (3) ◽  
Author(s):  
Max Laurence Cummins ◽  
Piklu Roy Chowdhury ◽  
Marc Serge Marenda ◽  
Glenn Francis Browning ◽  
Steven Philip Djordjevic
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Genome Sequencing ◽  
Genomic Island ◽  
Sequence Type ◽  
Genomic Islands ◽  
Content Type ◽  
E Coli ◽  
Antimicrobial Resistance Genes

ABSTRACT Salmonella genomic island 1 (SGI1) is an integrative genetic island first described in Salmonella enterica serovars Typhimurium DT104 and Agona in 2000. Variants of it have since been described in multiple serovars of S. enterica, as well as in Proteus mirabilis, Acinetobacter baumannii, Morganella morganii, and several other genera. The island typically confers resistance to older, first-generation antimicrobials; however, some variants carry blaNDM-1, blaVEB-6, and blaCTX-M15 genes that encode resistance to frontline, clinically important antibiotics, including third-generation cephalosporins. Genome sequencing studies of avian pathogenic Escherichia coli (APEC) identified a sequence type 117 (ST117) isolate (AVC96) with genetic features found in SGI1. The complete genome sequence of AVC96 was assembled from a combination of Illumina and single-molecule real-time (SMRT) sequence data. Analysis of the AVC96 chromosome identified a variant of SGI1-B located 18 bp from the 3′ end of trmE, also known as the attB site, a known hot spot for the integration of genomic islands. This is the first report of SGI1 in wild-type E. coli. The variant, here named SGI1-B-Ec1, was otherwise unremarkable, apart from the identification of ISEc43 in open reading frame (ORF) S023. IMPORTANCE SGI1 and variants of it carry a variety of antimicrobial resistance genes, including those conferring resistance to extended-spectrum β-lactams and carbapenems, and have been found in diverse S. enterica serovars, Acinetobacter baumannii, and other members of the Enterobacteriaceae. SGI1 integrates into Gram-negative pathogenic bacteria by targeting a conserved site 18 bp from the 3′ end of trmE. For the first time, we describe a novel variant of SGI1 in an avian pathogenic Escherichia coli isolate. The presence of SGI1 in E. coli is significant because it represents yet another lateral gene transfer mechanism to enhancing the capacity of E. coli to acquire and propagate antimicrobial resistance and putative virulence genes. This finding underscores the importance of whole-genome sequencing (WGS) to microbial genomic epidemiology, particularly within a One Health context. Further studies are needed to determine how widespread SGI1 and variants of it may be in Australia.

scholarly journals AbaR-Type Genomic Islands in Non-baumannii Acinetobacter Species Isolates from South Korea

2015 ◽  
Vol 59 (9) ◽  
pp. 5824-5826 ◽  
Author(s):  
Dae Hun Kim ◽  
Kwan Soo Ko
Keyword(s):  
South Korea ◽  
Acinetobacter Baumannii ◽  
Genomic Islands ◽  
Asian Countries ◽  
Acinetobacter Species ◽  
Content Type ◽  
South Korean

ABSTRACTTo investigate the presence and structure of AbaR-type genomic islands (GIs) in non-Acinetobacter baumanniiisolates, a total of 155 non-baumannii Acinetobacterisolates from a South Korean hospital were analyzed. GIs were found in threeAcinetobacter nosocomialisand twoAcinetobacter seifertiiisolates. Their structures were similar to those inA. baumanniiisolates from Asian countries, including South Korea. The existence of AbaR-type GIs in non-baumannii Acinetobacterisolates is believed to be due to interspecies transfer of GI.

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 Spread of Carbapenem-Resistant Acinetobacter baumannii Global Clone 2 in Asia and AbaR-Type Resistance Islands

2013 ◽  
Vol 57 (11) ◽  
pp. 5239-5246 ◽  
Author(s):  
Dae Hun Kim ◽  
Ji-Young Choi ◽  
Hae Won Kim ◽  
So Hyun Kim ◽  
Doo Ryeon Chung ◽  
...  
Keyword(s):  
Hong Kong ◽  
Acinetobacter Baumannii ◽  
Clonal Complex ◽  
Carbapenem Resistance ◽  
Surveillance Study ◽  
Structural Variations ◽  
Content Type ◽  
Resistance Determinants ◽  
Carbapenem Resistant ◽  
Resistance Island

ABSTRACTIn this surveillance study, we identified the genotypes, carbapenem resistance determinants, and structural variations of AbaR-type resistance islands among carbapenem-resistantAcinetobacter baumannii(CRAB) isolates from nine Asian locales. Clonal complex 92 (CC92), corresponding to global clone 2 (GC2), was the most prevalent in most Asian locales (83/108 isolates; 76.9%). CC108, or GC1, was a predominant clone in India. OXA-23 oxacillinase was detected in CRAB isolates from most Asian locales except Taiwan.blaOXA-24was found in CRAB isolates from Taiwan. AbaR4-type resistance islands, which were divided into six subtypes, were identified in most CRAB isolates investigated. Five isolates from India, Malaysia, Singapore, and Hong Kong contained AbaR3-type resistance islands. Of these, three isolates harbored both AbaR3- and AbaR4-type resistance islands simultaneously. In this study, GC2 was revealed as a prevalent clone in most Asian locales, with the AbaR4-type resistance island predominant, with diverse variants. The significance of this study lies in identifying the spread of global clones of carbapenem-resistantA. baumanniiin Asia.

scholarly journals Genetic Variability of Vancomycin-Resistant Enterococcus faecium and Enterococcus faecalis Isolates from Humans, Chickens, and Pigs in Malaysia

2013 ◽  
Vol 79 (15) ◽  
pp. 4528-4533 ◽  
Author(s):  
Yitbarek Getachew ◽  
Latiffah Hassan ◽  
Zunita Zakaria ◽  
Saleha Abdul Aziz
Keyword(s):  
Enterococcus Faecalis ◽  
Enterococcus Faecium ◽  
Clonal Complex ◽  
Housekeeping Genes ◽  
Vancomycin Resistant Enterococcus ◽  
Content Type ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Sequence Types ◽  
Representative Samples

ABSTRACTVancomycin-resistant enterococci (VRE) have been reported to be present in humans, chickens, and pigs in Malaysia. In the present study, representative samples of VRE isolated from these populations were examined for similarities and differences by using the multilocus sequence typing (MLST) method. Housekeeping genes ofEnterococcus faecium(n= 14) andEnterococcus faecalis(n= 11) isolates were sequenced and analyzed using the MLST databases eBURST and goeBURST. We found five sequence types (STs) ofE. faeciumand six STs ofE. faecalisexisting in Malaysia.Enterococcus faeciumisolates belonging to ST203, ST17, ST55, ST79, and ST29 were identified, andE. faeciumST203 was the most common among humans. The MLST profiles ofE. faeciumfrom humans in this study were similar to the globally reported nosocomial-related strain lineage belonging to clonal complex 17 (CC17). Isolates from chickens and pigs have few similarities to those from humans, except for one isolate from a chicken, which was identified as ST203.E. faecalisisolates were more diverse and were identified as ST4, ST6, ST87, ST108, ST274, and ST244, which were grouped as specific to the three hosts.E. faecalis, belonging to the high-risk CC2 and CC87, were detected among isolates from humans. In conclusion, even though one isolate from a chicken was found clonal to that of humans, the MLST analysis ofE. faeciumandE. faecalissupports the findings of others who suggest VRE to be predominantly host specific and that clinically important strains are found mainly among humans. The infrequent detection of a human VRE clone in a chicken may in fact suggest a reverse transmission of VRE from humans to animals.

scholarly journals High Frequency of OXA-253-Producing Acinetobacter baumannii in Different Hospitals in Recife, Brazil

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Felipe Lira de Sá Cavalcanti ◽  
Carina Lucena Mendes-Marques ◽  
Crhisllane Rafaele dos Santos Vasconcelos ◽  
Túlio de Lima Campos ◽  
Antonio Mauro Rezende ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
High Frequency ◽  
Resistance Determinant ◽  
Large Area ◽  
Content Type ◽  
Successful Transmission ◽  
Genetic Environment ◽  
Reported Data ◽  
Sequence Types

ABSTRACT Here, we report the isolation of 31 Acinetobacter baumannii strains producing OXA-253 in a single large Brazilian city. These strains belonged to five different sequence types (STs), including 4 STs not previously associated with bla OXA-253. In all strains, the bla OXA-253 gene was located in a plasmid within a genetic environment similar to what was found previously in Brazil and Italy. The reported data emphasize the successful transmission of the bla OXA-253 gene through a large area and the tendency for this resistance determinant to remain in the A. baumannii population.

scholarly journals Effects of Saline, an Ambient Acidic Environment, and Sodium Salicylate on OXA-Mediated Carbapenem Resistance in Acinetobacter baumannii: TABLE 1

2016 ◽  
Vol 60 (6) ◽  
pp. 3415-3418 ◽  
Author(s):  
Esther Zander ◽  
Harald Seifert ◽  
Paul G. Higgins
Keyword(s):  
Gene Expression ◽  
Acinetobacter Baumannii ◽  
Sodium Salicylate ◽  
Carbapenem Resistance ◽  
Low Ph ◽  
Wild Type ◽  
Experimental Conditions ◽  
Content Type ◽  
Reference Strains

Different physiological conditions, such as NaCl, low pH, and sodium salicylate, have been shown to affect antibiotic resistance determinants inAcinetobacter baumanniiisolates. Therefore, the aim of this study was to investigate the effects of NaCl, sodium salicylate, and low pH on the susceptibility ofA. baumanniito carbapenem. We cloned genes encoding oxacillinases (OXA) of different subclasses, with their associated promoters, from carbapenem-resistantA. baumanniiisolates into the same vector and transferred them to theA. baumanniireference strains ATCC 19606 and ATCC 17978. Carbapenem MICs were determined at least in triplicate by agar dilution under standard conditions, as well as in the presence of 200 mM NaCl or 16 mM sodium salicylate, or at pH 5.8. OXA-58-like gene expression was determined by reverse transcription-quantitative PCR (qRT-PCR). Under some experimental conditions, significant MIC reductions were shown for some transformants but not for others. Only in one instance were all transformants harboring the same OXA affected by the same condition: at pH 5.8, the imipenem and meropenem MICs for strains expressing OXA-58-like enzymes decreased from a resistant level (32 to 64 mg/liter) to an intermediate-susceptible level (8 mg/liter). However,blaOXA-58-likegene expression remained the same. MICs for both wild-type reference strains were not affected by the conditions tested. Our results indicate that the effects of the experimental conditions tested on OXAin vivoare mostly strain dependent. MICs were not reduced to wild-type levels, suggesting that the conditions tested do not lead to complete OXA inhibition in the bacterial cell.

scholarly journals In VitroandIn VivoAntimicrobial Activities of Gallium Nitrate against Multidrug-Resistant Acinetobacter baumannii

2012 ◽  
Vol 56 (11) ◽  
pp. 5961-5970 ◽  
Author(s):  
Luísa C. S. Antunes ◽  
Francesco Imperi ◽  
Fabrizia Minandri ◽  
Paolo Visca
Keyword(s):  
Human Serum ◽  
Acinetobacter Baumannii ◽  
Galleria Mellonella ◽  
Therapeutic Potential ◽  
Survival Rates ◽  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Gallium Nitrate ◽  
Content Type ◽  
Bacterial Physiology

ABSTRACTMultidrug-resistantAcinetobacter baumanniiposes a tremendous challenge to traditional antibiotic therapy. Due to the crucial role of iron in bacterial physiology and pathogenicity, we investigated iron metabolism as a possible target for anti-A. baumanniichemotherapy using gallium as an iron mimetic. Due to chemical similarity, gallium competes with iron for binding to several redox enzymes, thereby interfering with a number of essential biological reactions. We found that Ga(NO3)3, the active component of an FDA-approved drug (Ganite), inhibits the growth of a collection of 58A. baumanniistrains in both chemically defined medium and human serum, at concentrations ranging from 2 to 80 μM and from 4 to 64 μM, respectively. Ga(NO3)3delayed the entry ofA. baumanniiinto the exponential phase and drastically reduced bacterial growth rates. Ga(NO3)3activity was strongly dependent on iron availability in the culture medium, though the mechanism of growth inhibition was independent of dysregulation of gene expression controlled by the ferric uptake regulator Fur. Ga(NO3)3also protectedGalleria mellonellalarvae from lethalA. baumanniiinfection, with survival rates of ≥75%. At therapeutic concentrations for humans (28 μM plasma levels), Ga(NO3)3inhibited the growth in human serum of 76% of the multidrug-resistantA. baumanniiisolates tested by ≥90%, raising expectations on the therapeutic potential of gallium for the treatment ofA. baumanniibloodstream infections. Ga(NO3)3also showed strong synergism with colistin, suggesting that a colistin-gallium combination holds promise as a last-resort therapy for infections caused by pan-resistantA. baumannii.

scholarly journals Growth Retardation, Reduced Invasiveness, and Impaired Colistin-Mediated Cell Death Associated with Colistin Resistance Development in Acinetobacter baumannii

2013 ◽  
Vol 58 (2) ◽  
pp. 828-832 ◽  
Author(s):  
Spyros Pournaras ◽  
Aggeliki Poulou ◽  
Konstantina Dafopoulou ◽  
Yassine Nait Chabane ◽  
Ioulia Kristo ◽  
...  
Keyword(s):  
Cell Death ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Bloodstream Infections ◽  
Single Amino Acid ◽  
Colistin Resistance ◽  
Resistance Development ◽  
Content Type ◽  
Alkyl Hydroperoxide ◽  
Severe Soft Tissue

ABSTRACTTwo colistin-susceptible/colistin-resistant (Cols/Colr) pairs ofAcinetobacter baumanniistrains assigned to international clone 2, which is prevalent worldwide, were sequentially recovered from two patients after prolonged colistin administration. Compared with the respective Colsisolates (Ab248 and Ab299, both having a colistin MIC of 0.5 μg/ml), both Colrisolates (Ab249 and Ab347, with colistin MICs of 128 and 32 μg/ml, respectively) significantly overexpressedpmrCABgenes, had single-amino-acid shifts in the PmrB protein, and exhibited significantly slower growth. The Colrisolate Ab347, tested by proteomic analysis in comparison with its Colscounterpart Ab299, underexpressed the proteins CsuA/B and C from thecsuoperon (which is necessary for biofilm formation). This isolate also underexpressed aconitase B and different enzymes involved in the oxidative stress response (KatE catalase, superoxide dismutase, and alkyl hydroperoxide reductase), suggesting a reduced response to reactive oxygen species (ROS) and, consequently, impaired colistin-mediated cell death through hydroxyl radical production. Colsisolates that were indistinguishable by macrorestriction analysis from Ab299 caused six sequential bloodstream infections, and isolates indistinguishable from Ab248 caused severe soft tissue infection, while Colrisolates indistinguishable from Ab347 and Ab249 were mainly colonizers. In particular, a Colsisolate identical to Ab299 was still invading the bloodstream 90 days after the colonization of this patient by Colrisolates. These observations indicate considerably lower invasiveness ofA. baumanniiclinical isolates following the development of colistin resistance.

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