scholarly journals Characterization of Extremely Drug-Resistant and Hypervirulent Acinetobacter baumannii AB030

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 328
Author(s):  
Manu Singh ◽  
P. Malaka De Silva ◽  
Yasser Al-Saadi ◽  
Jacek Switala ◽  
Peter C. Loewen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Comparative Genomics ◽  
Acinetobacter Baumannii ◽  
Bacterial Pathogen ◽  
Multidrug Resistant ◽  
Mobile Elements ◽  
Drug Resistant

Acinetobacter baumannii is an important nosocomial bacterial pathogen. Multidrug-resistant isolates of A. baumannii are reported worldwide. Some A. baumannii isolates display resistance to nearly all antibiotics, making treatment of infections very challenging. As the need for new and effective antibiotics against A. baumannii becomes increasingly urgent, there is a need to understand the mechanisms of antibiotic resistance and virulence in this organism. In this work, comparative genomics was used to understand the mechanisms of antibiotic resistance and virulence in AB030, an extremely drug-resistant and hypervirulent strain of A. baumannii that is a representative of a recently emerged lineage of A. baumannii International Clone V. In order to characterize AB030, we carried out a genomic and phenotypic comparison with LAC-4, a previously described hyper-resistant and hypervirulent isolate. AB030 contains a number of antibiotic resistance- and virulence-associated genes that are not present in LAC-4. A number of these genes are present on mobile elements. This work shows the importance of characterizing the members of new lineages of A. baumannii in order to determine the development of antibiotic resistance and virulence in this organism.

scholarly journals Carbapenemase Genes and Multidrug Resistance of Acinetobacter Baumannii: A Cross Sectional Study of Patients with Pneumonia in Southern Vietnam

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 148 ◽  
Author(s):  
Cuong Hoang Quoc ◽  
Thao Nguyen Thi Phuong ◽  
Hai Nguyen Duc ◽  
Trung Tran Le ◽  
Hang Tran Thi Thu ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Demographic Data ◽  
Treatment Options ◽  
Bacterial Pathogen ◽  
Multidrug Resistant ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Carbapenem Resistant ◽  
Hospital Acquired

Background: Acinetobacter baumannii (Ab) is an opportunistic bacterial pathogen found in hospital-acquired infections including nosocomial pneumonia, especially multidrug-resistant Ab. This study aims to survey the drug resistance profiles of Ab isolated from patients in Thong Nhat Dong Nai General Hospital and assess the relationship between genotypes and antibiotic resistance; Methods: Ninety-seven Ab strains isolated from 340 lower respiratory tract specimens among pneumonia patients were used to screen the most common local carbapenemase genes. Antimicrobial susceptibility testing results and demographic data were collected and minimum inhibitory concentrations (MIC) of colistin were also determined; Results: Over 80% and 90% of Ab strains were determined as carbapenem-resistant and multidrug-resistant (MDR), respectively. Most of the strains carried carbapenemase genes, including blaOXA-51, blaOXA-23-like, blaOXA-58-like, and blaNDM-1, with proportions of 97 (100%), 76 (78.4%), 10 (10.3%), 6 (6.2%), respectively. Amongst these genes, blaOXA-23-like was the only gene which significantly influenced the resistance (p < 0.0001); and Conclusions: The severity of Ab antibiotic resistance is urgent and specifically related to carbapenemase encoding genes. Therefore, screening of MDR Ab and carbapenemase for better treatment options is necessary.

scholarly journals Epidemiology and Genetic Diversity of Colistin Nonsusceptible Nosocomial Acinetobacter baumannii Strains from Russia for 2013-2014

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Eugene A. Sheck ◽  
Mikhail V. Edelstein ◽  
Marina V. Sukhorukova ◽  
Natali V. Ivanchik ◽  
Elena Yu. Skleenova ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Nosocomial Infections ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Extensively Drug Resistant ◽  
Epidemiological Features ◽  
High Level ◽  
Therapeutic Possibilities

A high level of resistance to carbapenems in Acinetobacter baumannii strains severely limits therapeutic possibilities. Colistin is the last resort drug against such strains, although the cases of resistance to this drug have become more frequent. This article presents the epidemiological features and genetic diversity of colistin nonsusceptible A. baumannii strains collected as part of a national multicenter epidemiological study of the antibiotic resistance of pathogens of nosocomial infections (MARATHON), which was conducted in 2013-2014 in Russia. A total of 527 A. baumannii isolates were collected, 10 (1.9%) of which were nonsusceptible to colistin. The majority of nonsusceptible A. baumannii isolates to colistin showed resistance to carbapenems and had the genes of the acquired OXA-40-like carbapenemases (n=6). In one case, a combination of OXA-23-like + OXA-40-like (n=1) genes was identified. One strain had the multidrug-resistant (MDR) phenotype, 6 isolates had extensively drug-resistant (XDR) phenotype, and 3 isolates had pandrug-resistant (PDR) phenotype. Among the colistin nonsusceptible A. baumannii isolates, 6 individual genotypes were identified, most of which belonged to successful international clones (CC92OXF/CC2PAS, n=4; CC944OXF/ST78PAS, n=4; CC109OXF/CC1PAS, n=1).

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.

Emergence and characterization of nosocomial multidrug-resistant and extensively drug-resistant Acinetobacter baumannii isolates in Tehran, Iran

2018 ◽  
Vol 24 (7) ◽  
pp. 515-523 ◽  
Author(s):  
Bahare Salehi ◽  
Hossein Goudarzi ◽  
Bahram Nikmanesh ◽  
Hamidreza Houri ◽  
Mostafa Alavi-Moghaddam ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Extensively Drug Resistant

Distribution of Pathogens Involved in Infections in Oncological Patients and their Antibiotic Resistance Profile

2020 ◽  
Vol 70 (12) ◽  
pp. 4287-4294
Keyword(s):  
Antibiotic Resistance ◽  
Cancer Patients ◽  
Bacterial Pathogen ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Antibiotic Resistance Profile ◽  
Oncological Patients ◽  
Eastern European Countries ◽  
Klebsiella Spp

Cancer is the second leading cause of death in Romania and worldwide. Cancer patients are at increasing risk of acquiring bacterial infection with multi-resistant germs, including multidrug-resistant (MDR) strains of Gram-negative bacteria involved in nosocomial infection. Romania is one of the South-Eastern European countries with one of the highest prevalence rates of MDR pathogens. To determine the resistance pattern of bacterial profile and antibiotic resistance pattern in cancer patients admitted at the County Emergency Clinical Hospital Craiova, Romania. A retrospective study of bacterial pathogens was carried out on 90 adult cancer patients admitted from January to December 2018. The analysis of the resistance patterns for the action of the appropriate antibiotics was performed using Vitek 2 Compact system and diffusion method. In this study there were analysed 92 samples from 90 oncological patients (37-86 years). A total of 157 bacterial isolates were obtained, of which 37 strains of Staphylococcus aureus (23.56%), followed by Streptococcus pneumoniae (23- 14.64%), Klebsiella spp. and Escherichia coli (22 - 14,01%). The most common isolates were from respiratory tract (86 isolates - 54.77%). High rates of MDR were found for E. coli (63.63%), MRSA (61,11%) and Klebsiella spp. (54,54%), while one third of the isolated strains of Pseudomonas aeruginosa, Acinetobacter spp. and Proteus spp. were MDR. The findings of this study may be the basis for further more extensive studies highlighting the germs involved in the infectious pathology of cancer patients, in order to determine the antimicrobial resistance and to improve the methods of prophylaxis and treatment. Keywords: multidrug resistance (MDR), cancer patients, bacterial pathogen

scholarly journals Radiation-Inactivated Acinetobacter baumannii Vaccine Candidates

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 96
Author(s):  
Stephen J. Dollery ◽  
Daniel V. Zurawski ◽  
Elena K. Gaidamakova ◽  
Vera Y. Matrosova ◽  
John K. Tobin ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Treatment Options ◽  
Bacterial Pathogen ◽  
Multidrug Resistant ◽  
Bacterial Cells ◽  
Wound Infections ◽  
Protein Profiles ◽  
Vaccine Candidates ◽  
Rich Media ◽  
Life Threatening

Acinetobacter baumannii is a bacterial pathogen that is often multidrug-resistant (MDR) and causes a range of life-threatening illnesses, including pneumonia, septicemia, and wound infections. Some antibiotic treatments can reduce mortality if dosed early enough before an infection progresses, but there are few other treatment options when it comes to MDR-infection. Although several prophylactic strategies have been assessed, no vaccine candidates have advanced to clinical trials or have been approved. Herein, we rapidly produced protective whole-cell immunogens from planktonic and biofilm-like cultures of A. baumannii, strain AB5075 grown using a variety of methods. After selecting a panel of five cultures based on distinct protein profiles, replicative activity was extinguished by exposure to 10 kGy gamma radiation in the presence of a Deinococcus antioxidant complex composed of manganous (Mn2+) ions, a decapeptide, and orthophosphate. Mn2+ antioxidants prevent hydroxylation and carbonylation of irradiated proteins, but do not protect nucleic acids, yielding replication-deficient immunogenic A. baumannii vaccine candidates. Mice were immunized and boosted twice with 1.0 × 107 irradiated bacterial cells and then challenged intranasally with AB5075 using two mouse models. Planktonic cultures grown for 16 h in rich media and biofilm cultures grown in static cultures underneath minimal (M9) media stimulated immunity that led to 80–100% protection.

scholarly journals Multidrug-Resistant Enterococci Lack CRISPR-cas

mBio ◽  
2010 ◽  
Vol 1 (4) ◽  
Author(s):  
Kelli L. Palmer ◽  
Michael S. Gilmore
Keyword(s):  
Antibiotic Resistance ◽  
Draft Genome ◽  
Inverse Correlation ◽  
Multidrug Resistant ◽  
Mobile Elements ◽  
Mobile Dna ◽  
Data Set ◽  
Content Type ◽  
Genome Defense ◽  
Acquired Antibiotic Resistance

ABSTRACT Clustered, regularly interspaced short palindromic repeats (CRISPR) provide bacteria and archaea with sequence-specific, acquired defense against plasmids and phage. Because mobile elements constitute up to 25% of the genome of multidrug-resistant (MDR) enterococci, it was of interest to examine the codistribution of CRISPR and acquired antibiotic resistance in enterococcal lineages. A database was built from 16 Enterococcus faecalis draft genome sequences to identify commonalities and polymorphisms in the location and content of CRISPR loci. With this data set, we were able to detect identities between CRISPR spacers and sequences from mobile elements, including pheromone-responsive plasmids and phage, suggesting that CRISPR regulates the flux of these elements through the E. faecalis species. Based on conserved locations of CRISPR and CRISPR-cas loci and the discovery of a new CRISPR locus with associated functional genes, CRISPR3-cas, we screened additional E. faecalis strains for CRISPR content, including isolates predating the use of antibiotics. We found a highly significant inverse correlation between the presence of a CRISPR-cas locus and acquired antibiotic resistance in E. faecalis, and examination of an additional eight E. faecium genomes yielded similar results for that species. A mechanism for CRISPR-cas loss in E. faecalis was identified. The inverse relationship between CRISPR-cas and antibiotic resistance suggests that antibiotic use inadvertently selects for enterococcal strains with compromised genome defense. IMPORTANCE For many bacteria, including the opportunistically pathogenic enterococci, antibiotic resistance is mediated by acquisition of new DNA and is frequently encoded on mobile DNA elements such as plasmids and transposons. Certain enterococcal lineages have recently emerged that are characterized by abundant mobile DNA, including numerous viruses (phage), and plasmids and transposons encoding multiple antibiotic resistances. These lineages cause hospital infection outbreaks around the world. The striking influx of mobile DNA into these lineages is in contrast to what would be expected if a self (genome)-defense system was present. Clustered, regularly interspaced short palindromic repeat (CRISPR) defense is a recently discovered mechanism of prokaryotic self-defense that provides a type of acquired immunity. Here, we find that antibiotic resistance and possession of complete CRISPR loci are inversely related and that members of recently emerged high-risk enterococcal lineages lack complete CRISPR loci. Our results suggest that antibiotic therapy inadvertently selects for enterococci with compromised genome defense.

scholarly journals Characterization of Two Multidrug-Resistant IncA/C Plasmids from the 1960s by Using the MinION Sequencer Device

2016 ◽  
Vol 60 (11) ◽  
pp. 6780-6786 ◽  
Author(s):  
Mónika Szabó ◽  
Tibor Nagy ◽  
Tímea Wilk ◽  
Tibor Farkas ◽  
Anna Hegyi ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Genome ◽  
Multidrug Resistant ◽  
Phenotypic Change ◽  
Long Reads ◽  
Loss Of Resistance ◽  
Rapid Characterization ◽  
Resistance Island ◽  
The 1960S

ABSTRACTTwo A/C incompatibility group (IncA/C family) plasmids from the 1960s have been sequenced and classified into the A/C2type 1 group. R16a and IP40a contain novel antibiotic resistance islands and a complete GIsul2 genomic island not previously found in the family. In the 173.1-kb R16a, the 29.9-kb antibiotic resistance island (ARI) is located in a unique backbone position not utilized by ARIs. ARIR16aconsists of Tn1, Tn6020, and Tn6333, harboring the resistance genesblaTEM-1DandaphA1band amermodule, respectively; a truncated Tn5393copy; and a gene cluster with unknown function. Plasmid IP40a is 170.4 kb in size and contains a 5.6-kb ARI inserted into thekfrAgene. ARIIP40acarryingblaTEM-1DandaphA1bgenes is composed of Tn1with a Tn6023insertion. Additionally, IP40a harbors single IS2, IS186, and Tn1000insertions scattered in the backbone; an IS150copy in GIsul2; and a complete Tn6333carrying amermodule at the position of ARIR16a. Loss of resistance markers in R16a, IP40a, and R55 was observed during stability tests. Every phenotypic change proved to be the result of recombination events involving mobile elements. Intramolecular transposition of IS copies that generated IP40a derivatives lacking large parts of the backbone could account for the formation of other family members, too. The MinION platform proved to be a valuable tool in bacterial genome sequencing since it generates long reads that span repetitive elements and facilitates full-length plasmid or chromosome assembly. Nanopore technology enables rapid characterization of large, low-copy-number plasmids and their rearrangement products.

scholarly journals Pheromone killing of multidrug-resistantEnterococcus faecalisV583 by native commensal strains

2015 ◽  
Vol 112 (23) ◽  
pp. 7273-7278 ◽  
Author(s):  
Michael S. Gilmore ◽  
Marcus Rauch ◽  
Matthew M. Ramsey ◽  
Paul R. Himes ◽  
Sriram Varahan ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Cross Talk ◽  
Metabolic Pathways ◽  
Multidrug Resistant ◽  
Mobile Elements ◽  
Competitive Growth ◽  
Gi Tract ◽  
Subsequent Infection ◽  
Native Flora ◽  
Resistant Strains

Multidrug-resistantEnterococcus faecalispossess numerous mobile elements that encode virulence and antibiotic resistance traits as well as new metabolic pathways, often constituting over one-quarter of the genome. It was of interest to determine how this large accretion of mobile elements affects competitive growth in the gastrointestinal (GI) tract consortium. We unexpectedly observed that the prototype clinical isolate strain V583 was actively killed by GI tract flora, whereas commensal enterococci flourished. It was found that killing of V583 resulted from lethal cross-talk between accumulated mobile elements and that this cross-talk was induced by a heptapeptide pheromone produced by nativeE. faecalispresent in the fecal consortium. These results highlight two important aspects of the evolution of multidrug-resistant enterococci: (i) the accretion of mobile elements inE. faecalisV583 renders it incompatible with commensal strains, and (ii) because of this incompatibility, multidrug-resistant strains sharing features found in V583 cannot coexist with commensal strains. The accumulation of mobile elements in hospital isolates of enterococci can include those that are inherently incompatible with native flora, highlighting the importance of maintaining commensal populations as means of preventing colonization and subsequent infection by multidrug-resistant strains.

Sign in / Sign up

Export Citation Format

Share Document