scholarly journals Lyb-2-4, a unique genomic region of hypervirulent carbapenem-resistant Acinetobacter baumannii

2019 ◽  
Author(s):  
Chao Zheng ◽  
Jinyong Zhang ◽  
Min Zhang ◽  
Zhou Liu ◽  
Yuxin Zhong ◽  
...  
Keyword(s):  
Mouse Model ◽  
Acinetobacter Baumannii ◽  
Multilocus Sequence Typing ◽  
Core Genome ◽  
Medical Intervention ◽  
Genomic Region ◽  
Multi Drug Resistance ◽  
Comparative Genomic ◽  
Low Grade ◽  
Carbapenem Resistant

ABSTRACTAcinetobacter baumannii is an important human pathogen due to its multi-drug resistance, but is usually with low-grade virulence. Although a mouse model revealed different virulence grades of clinical carbapenem-resistant A. baumannii (CRAB) strains, the genetic basis remains unknown. We collected 61 CRAB isolates from intensive care unit of Shenzhen People’s Hospital (Shenzhen, China), and analyzed them used whole genome sequencing (WGS), multilocus sequence typing (MLST) and core genome MLST (cgMLST), transmission chain reconstruction and Comparative genomic tools. A mouse pneumonia model was used to confirm the hypervirulent phenotype. Eleven complex types (CT) were identified based on core genome multilocus sequence typing scheme. CT512 showed higher transmissibility and bloodstream infection rates than other CTs. A genomic region Lyb-2-4 was shared by CT512 and CT2092 but not CT2085. The mortality rates of patient infected with CRAB harboring Lyb-2-4 was significantly higher than those infected with CRAB isolates without Lyb-2-4 (77.8% vs 24.5%, p < 0.01). In the mouse model, the survival rates of strains containing the Lyb-2-4 region (LAC-4, 5122 and 2092) were significantly lower than for strains without Lyb-2-4 (7152, 71517, 20859 and ATCC17978). One open reading frame (ORF) was a marker for the presence of Lyb-2-4, and PCR of a segment of this ORF, designated as hvcT, served as a tag for hypervirulent CRAB. Our study should be very useful in advising the clinician to implement medical intervention earlier, and also making the worldwide surveillance of these hypervirulent CRAB strains easier.IMPORTANCEHypervirulent CRAB strains are expected to pose a threat to human health because infection of these strains is associated with high mortality and multidrug resistance. The rapid hypervirulent CRAB identification assay will facilitate prompt medical intervention. Our findings should provoke surveillance for hypervirulent CRAB strains harboring Lyb-2-4 in other countries. Further research should focus on the mechanism of hypervirulence, the acquisition of this genomic region and the development of control measures to prevent further dissemination.

scholarly journals Epidemiological investigation of an Acinetobacter baumannii outbreak using core genome multilocus sequence typing

2019 ◽  
Vol 17 ◽  
pp. 245-249 ◽  
Author(s):  
Carolina Venditti ◽  
Antonella Vulcano ◽  
Silvia D’Arezzo ◽  
Cesare Ernesto Maria Gruber ◽  
Marina Selleri ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Multilocus Sequence Typing ◽  
Core Genome ◽  
Epidemiological Investigation

scholarly journals In vivo efficacy of combination of colistin with fosfomycin or minocycline in a mouse model of multidrug-resistant Acinetobacter baumannii pneumonia

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nam Su Ku ◽  
Su-Hyung Lee ◽  
Young- soun Lim ◽  
Heun Choi ◽  
Jin Young Ahn ◽  
...  
Keyword(s):  
Mouse Model ◽  
Acinetobacter Baumannii ◽  
Synergistic Effects ◽  
Bacterial Load ◽  
Multidrug Resistant ◽  
Therapeutic Options ◽  
Severance Hospital ◽  
Carbapenem Resistant ◽  
Combination Regimens

AbstractUnfortunately, the options for treating multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii) infections are extremely limited. Recently, fosfomycin and minocycline were newly introduced as a treatment option for MDR A. baumannii infection. Therefore, we investigated the efficacy of the combination of colistin with fosfomycin and minocycline, respectively, as therapeutic options in MDR A. baumannii pneumonia. We examined a carbapenem-resistant A. baumannii isolated from clinical specimens at Severance Hospital, Seoul, Korea. The effect of colistin with fosfomycin, and colistin with minocycline on the bacterial counts in lung tissue was investigated in a mouse model of pneumonia caused by MDR A. baumannii. In vivo, colistin with fosfomycin or minocycline significantly (p < 0.05) reduced the bacterial load in the lungs compared with the controls at 24 and 48 h. In the combination groups, the bacterial loads differed significantly (p < 0.05) from that with the more active antimicrobial alone. Moreover, the combination regimens of colistin with fosfomycin and colistin with minocycline showed bactericidal and synergistic effects compared with the more active antimicrobial alone at 24 and 48 h. This study demonstrated the synergistic effects of combination regimens of colistin with fosfomycin and minocycline, respectively, as therapeutic options in pneumonia caused by MDR A. baumannii.

scholarly journals Biofilm Formation and Detection of Fluoroquinolone- and Carbapenem-Resistant Genes in Multidrug-Resistant Acinetobacter baumannii

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
María-Guadalupe Avila-Novoa ◽  
Oscar-Alberto Solís-Velázquez ◽  
Daniel-Eduardo Rangel-López ◽  
Jean-Pierre González-Gómez ◽  
Pedro-Javier Guerrero-Medina ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Low Grade ◽  
Carbapenem Resistant ◽  
Hospital Environments ◽  
Potential Association ◽  
Clinical Environments

Acinetobacter baumannii is an important opportunistic pathogen that shows resistance to cephalosporins, penicillins, carbapenems, fluoroquinolones, and aminoglycosides, the multiresistance being associated with its ability to form biofilms in clinical environments. The aim of this study was to determine biofilm formation and its potential association with genes involved in antibiotic resistance mechanisms of A. baumannii isolates of different clinical specimens. We demonstrated 100% of the A. baumannii isolates examined to be multidrug resistant (MDR), presenting a 73.3% susceptibility to cefepime and a 53.3% susceptibility to ciprofloxacin. All A. baumannii isolates were positive for blaOXA-51, 33.3% being positive for blaOXA-23 and ISAba1, and 73.3% being positive for gyrA. We found 86.6% of A. baumannii strains to be low-grade biofilm formers and 13.3% to be biofilm negative; culturing on Congo red agar (CRA) plates revealed that 73.3% of the A. baumannii isolates to be biofilm producers, while 26.6% were not. These properties, combined with the role of A. baumannii as a nosocomial pathogen, increase the probability of A. baumannii causing nosocomial infections and outbreaks as a complication during therapeutic treatments and emphasize the need to control A. baumannii biofilms in hospital environments.

scholarly journals Piscidin is Highly Active against Carbapenem-Resistant Acinetobacter baumannii and NDM-1-Producing Klebsiella pneumonia in a Systemic Septicaemia Infection Mouse Model

Marine Drugs ◽  
2015 ◽  
Vol 13 (4) ◽  
pp. 2287-2305 ◽  
Author(s):  
Chieh-Yu Pan ◽  
Jian-Chyi Chen ◽  
Te-Li Chen ◽  
Jen-Leih Wu ◽  
Cho-Fat Hui ◽  
...  
Keyword(s):  
Mouse Model ◽  
Acinetobacter Baumannii ◽  
Klebsiella Pneumonia ◽  
Highly Active ◽  
Carbapenem Resistant

scholarly journals Population Structure Analysis of Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates from Brazil Reveals Predominance of Clonal Complexes 1, 15, and 79

2016 ◽  
Vol 60 (4) ◽  
pp. 2545-2547 ◽  
Author(s):  
Carlos Henrique Camargo ◽  
Monique Ribeiro Tiba ◽  
Marta Regina Saes ◽  
Francielli Mahnic de Vasconcellos ◽  
Luis Fernando dos Santos ◽  
...  
Keyword(s):  
Population Structure ◽  
Acinetobacter Baumannii ◽  
Gel Electrophoresis ◽  
Multilocus Sequence Typing ◽  
Clonal Complex ◽  
Pulsed Field Gel Electrophoresis ◽  
Clinical Isolates ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Population Structure Analysis

ABSTRACTThe population structure of 71 carbapenem-resistantAcinetobacter baumanniiclinical isolates from several hospitals in Brazil was investigated by ApaI pulsed-field gel electrophoresis,blaOXA-51-like subtyping, and multilocus sequence typing (Institute Pasteur scheme). In addition to the predominance of strains carryingblaOXA-23, we detected the presence ofblaOXA-72andblaOXA-231. We observed a predominance of clonal complex 1 (CC1), CC15, and CC79 and representative strains of the worldwide-disseminated international clone I.

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 Acinetobacter baumannii: Its Clinical Significance in Human and Veterinary Medicine

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 127
Author(s):  
Francesca Paola Nocera ◽  
Anna-Rita Attili ◽  
Luisa De Martino
Keyword(s):  
Veterinary Medicine ◽  
Acinetobacter Baumannii ◽  
Nosocomial Infections ◽  
Recent Literature ◽  
Opportunistic Pathogen ◽  
Human Medicine ◽  
Multi Drug Resistance ◽  
Carbapenem Resistant ◽  
Severe Infections ◽  
Environmental Adaptability

Acinetobacter baumannii is a Gram-negative, opportunistic pathogen, causing severe infections difficult to treat. The A. baumannii infection rate has increased year by year in human medicine and it is also considered as a major cause of nosocomial infections worldwide. This bacterium, also well known for its ability to form biofilms, has a strong environmental adaptability and the characteristics of multi-drug resistance. Indeed, strains showing fully resistant profiles represent a worrisome problem in clinical therapeutic treatment. Furthermore, A. baumannii-associated veterinary nosocomial infections has been reported in recent literature. Particularly, carbapenem-resistant A. baumannii can be considered an emerging opportunistic pathogen in human medicine as well as in veterinary medicine.

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