scholarly journals Molecular Epidemiology and Clone Transmission of Carbapenem-Resistant Acinetobacter baumannii in ICU Rooms

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiufeng Zhang ◽  
Fangping Li ◽  
Furqan Awan ◽  
Hongye Jiang ◽  
Zhenling Zeng ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Core Genome ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Chi Square ◽  
The Core ◽  
Carbapenem Resistant ◽  
Significant Difference ◽  
Chi Square Test

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major cause of nosocomial infections and hospital outbreaks worldwide, remaining a critical clinical concern. Here we characterized and investigated the phylogenetic relationships of 105 CRAB isolates from an intensive care unit from one hospital in China collected over six years. All strains carried blaOXA-23, blaOXA-66 genes for carbapenem resistance, also had high resistance gene, virulence factor, and insertion sequence burdens. Whole-genome sequencing revealed all strains belonged to ST2, the global clone CC2. The phylogenetic analysis based on the core genome showed all isolates were dominated by a single lineage of three clusters and eight different clones. Two clones were popular during the collection time. Using chi-square test to identify the epidemiologically meaningful groupings, we found the significant difference in community structure only existed in strains from separation time. The haplotype and median-joining network analysis revealed genetic differences appeared among clusters and changes occurred overtime in the dominating cluster. Our results highlighted substantial multidrug-resistant CRAB burden in the hospital ICU environment demonstrating potential clone outbreak in the hospital.

scholarly journals Molecular epidemiology and clone transmission of carbapenem-resistant Acinetobacter baumannii in ICU rooms

2020 ◽  
Author(s):  
Xiufeng Zhang ◽  
Fangping Li ◽  
Zhuangwei Hou ◽  
Furqan Awan ◽  
Hongye Jiang ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Core Genome ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Chi Square ◽  
The Core ◽  
Carbapenem Resistant ◽  
Significant Difference ◽  
Chi Square Test ◽  
Collection Time

AbstractCarbapenem-resistant Acinetobacter baumannii (CRAB) is a major cause of nosocomial infections and hospital outbreaks worldwide, remaining a critical clinical concern. Here we characterized and investigated the phylogenetic relationships of 105 CRAB isolates on intensive care unit surfaces from one hospital in China collected over six years. All strains carried blaOXA-23, blaOXA-66 genes for carbapenem resistance, also had high resistance gene, virulence factor and insertion sequences burdens. Whole-genome sequencing revealed all strains belonged to ST2, the global clone CC2. The phylogenetic analysis based on the core genome showed all isolates was dominated by a single lineage of three clusters and eight different clones. Two clones were popular during the collection time. Using chi-square test to identify the epidemiologically meaningful groupings, we found the significant difference in community structure only present in strains from separation time. The haplotype and median-joining network analysis revealed genetic differences among clusters and changes occurred overtime in the dominating cluster. Our results highlighted substantial multidrug-resistant CRAB burden in hospital ICU environment, demonstrated potential clone outbreak in hospital.

scholarly journals Phenotypic Detection of Carbapenemase Production in Carbapenem-Resistant Enterobacteriaceae by Modified Hodge Test and Modified Strip Carba NP Test

2021 ◽  
Author(s):  
Nisha Patidar ◽  
Nitya Vyas ◽  
Shanoo Sharma ◽  
Babita Sharma
Keyword(s):  
Carbapenem Resistance ◽  
Nonparametric Test ◽  
Multidrug Resistant ◽  
Clinical Samples ◽  
Chi Square ◽  
Carbapenem Resistant ◽  
The Social ◽  
Significant Difference ◽  
High Degree ◽  
Carbapenem Resistant Enterobacteriaceae

Abstract Objective Carbapenems are last resort antibiotics for multidrug-resistant Enterobacteriaceae. However, resistance to carbapenem is increasing at an alarming rate worldwide leading to major therapeutic failures and increased mortality rate. Early and effective detection of carbapenemase producing carbapenem-resistant Enterobacteriaceae (CRE) is therefore key to control dissemination of carbapenem resistance in nosocomial as well as community-acquired infection. The aim of present study was to evaluate efficacy of Modified strip Carba NP (CNP) test against Modified Hodge test (MHT) for early detection of carbapenemase producing Enterobacteriaceae (CPE). Material and Methods Enterobacteriaceae isolated from various clinical samples were screened for carbapenem resistance. A total of 107 CRE were subjected to MHT and Modified strip CNP test for the detection of CPE. Statistical Analysis It was done on Statistical Package for the Social Sciences (SPSS) software, IBM India; version V26. Nonparametric test chi-square and Z-test were used to analyze the results within a 95% level of confidence. Results Out of 107 CRE, 94 (88%) were phenotypically confirmed as carbapenemase producer by Modified strip CNP test and 46 (43%) were confirmed by Modified Hodge Test (MHT). Thirty-eight (36%) isolates showed carbapenemase production by both MHT and CNP test, 56 isolates (52%) were CNP test positive but MHT negative, eight (7%) isolates were MHT positive but CNP test negative and five (5%) isolates were both MHT and CNP test negative. There is statistically significant difference in efficiency of Modified CNP test and MHT (p < 0.05). Conclusion Modified strip CNP test is simple and inexpensive test which is easy to perform and interpret and gives rapid results in less than 5 minutes. It has high degree of sensitivity and specificity. Modified strip CNP test shows significantly higher detection capacity for carbapenemase producers as compared with MHT.

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 A Plasmid-Borne blaOXA-58 Gene Confers Imipenem Resistance to Acinetobacter baumannii Isolates from a Lebanese Hospital

2008 ◽  
Vol 52 (11) ◽  
pp. 4115-4120 ◽  
Author(s):  
Raffaele Zarrilli ◽  
Domenico Vitale ◽  
Anna Di Popolo ◽  
Maria Bagattini ◽  
Ziad Daoud ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Mosaic Structure ◽  
University Hospital ◽  
Origins Of Replication ◽  
Imipenem Resistance ◽  
Reading Frames

ABSTRACT We investigated the basis of the carbapenem resistance of 17 multidrug-resistant Acinetobacter baumannii clinical isolates collected from 2004 to 2005 at the Saint George University Hospital in Beirut, Lebanon. A. baumannii isolates were clonally related and were susceptible to colistin and trimethoprim-sulfamethoxazole, susceptible or intermediate to ampicillin-sulbactam and meropenem, and resistant to all other antimicrobials. Conjugation experiments demonstrated that resistance to imipenem could be transferred along with a plasmid containing the carbapenem-hydrolyzing oxacillinase bla OXA-58 gene. The plasmid that we called pABIR was 29,823 bp in size and showed a novel mosaic structure composed of two origins of replication, four insertion sequence (IS) elements, and 28 open reading frames. The bla OXA-58 gene was flanked by IS18 and ISAba3 elements at the 5′ and 3′ ends, respectively. The production of the carbapenem-hydrolyzing oxacillinase OXA-58 was apparently the only mechanism for carbapenem resistance in A. baumannii isolates causing the outbreak at the Lebanese Hospital.

scholarly journals Colistin and Carbapenem-Resistant Acinetobacter baumannii Aci46 in Thailand: Genome Analysis and Antibiotic Resistance Profiling

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1054
Author(s):  
Nalumon Thadtapong ◽  
Soraya Chaturongakul ◽  
Sunhapas Soodvilai ◽  
Padungsri Dubbs
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Antibiotic Resistance Genes ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Whole Genome ◽  
Disk Diffusion Method ◽  
Genome Data ◽  
Carbapenem Resistant

Resistance to the last-line antibiotics against invasive Gram-negative bacterial infection is a rising concern in public health. Multidrug resistant (MDR) Acinetobacter baumannii Aci46 can resist colistin and carbapenems with a minimum inhibitory concentration of 512 µg/mL as determined by microdilution method and shows no zone of inhibition by disk diffusion method. These phenotypic characteristics prompted us to further investigate the genotypic characteristics of Aci46. Next generation sequencing was applied in this study to obtain whole genome data. We determined that Aci46 belongs to Pasture ST2 and is phylogenetically clustered with international clone (IC) II as the predominant strain in Thailand. Interestingly, Aci46 is identical to Oxford ST1962 that previously has never been isolated in Thailand. Two plasmids were identified (pAci46a and pAci46b), neither of which harbors any antibiotic resistance genes but pAci46a carries a conjugational system (type 4 secretion system or T4SS). Comparative genomics with other polymyxin and carbapenem-resistant A. baumannii strains (AC30 and R14) identified shared features such as CzcCBA, encoding a cobalt/zinc/cadmium efflux RND transporter, as well as a drug transporter with a possible role in colistin and/or carbapenem resistance in A. baumannii. Single nucleotide polymorphism (SNP) analyses against MDR ACICU strain showed three novel mutations i.e., Glu229Asp, Pro200Leu, and Ala138Thr, in the polymyxin resistance component, PmrB. Overall, this study focused on Aci46 whole genome data analysis, its correlation with antibiotic resistance phenotypes, and the presence of potential virulence associated factors.

Antibiotic resistance pattern of Acinetobacter baumannii from burns patients: increase in prevalence of blaOXA-24-like and blaOXA-58-like genes

2020 ◽  
Author(s):  
Niloofar Tafreshi ◽  
Laleh Babaeekhou ◽  
Maryam Ghane
Keyword(s):  
Acinetobacter Baumannii ◽  
Insertion Sequence ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Resistance Pattern ◽  
Drug Resistant ◽  
Burn Wound ◽  
Beta Lactamases ◽  
First Time

Background and Objectives: Notwithstanding the increased prevalence of Acinetobacter baumannii drug-resistant isolates, treatment options are progressively limiting. This study aims to provide a recent report on antibiotic susceptibility in burn wound isolates of A. baumannii, and the importance of OXA beta-lactamases in carbapenem resistance. Materials and Methods: The susceptibility levels to different antimicrobial categories were determined among 84 A. baumannii isolates from burn wound infection between 2016 and 2018. Multiplex PCR was used to detect OXA beta-lactamases genes, including blaOXA-51, blaOXA-23, blaOXA-24 and blaOXA-58. ISAba-1 association with blaOXA-51, blaOXA-23 and blaOXA-58 was detected by PCR mapping. Results: All the isolates were determined as multidrug-resistant (MDR) and 69% as extensively drug-resistant (XDR). Different carbapenems MIC ranges (MIC50 and MIC90) were observed among the isolates harboring blaOXA-like genes and isolates with the OXA-24-like enzyme showed higher carbapenems MIC ranges. The prevalence of blaOXA-51-like, blaOXA-23-like, blaOXA-24-like and blaOXA-58-like were 100%, 53.57%, 41.66% and 30.95%, respectively. ISAba-1 insertion sequence was found to be upstream to blaOXA-23-like and blaOXA-58-like genes in 23 out of 45 (71.1%) blaOXA-23-like-positive and 4 out of 23 (15.3) blaOXA-58-like-positive isolates, respectively. Conclusion: Resistance to carbapenems as the last resort for treatment of A. baumannii infections is growing. This study, for the first time in Iran, has observed the increased frequency of blaOXA-24-like and blaOXA-58-like genes and found an association between ISAba-1 and blaOXA-58-like gene, which signifies the possible risk of increased diversity in OXA beta-lactamases and growth in carbapenem resistance

scholarly journals Expression of Efflux Pumps, Porins and Genotypic Insight Into the Carbapenem Resistance in Acinetobacter Baumannii

2021 ◽  
Author(s):  
Alka Hasani ◽  
Abolfazl vahhabi ◽  
Mohammad Ahangarzadeh Rezaee ◽  
Behzad Baradaran ◽  
Akbar Hasani ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Carbapenem Resistance ◽  
Standard Of Care ◽  
Efflux Pumps ◽  
Multidrug Resistant ◽  
Simultaneous Occurrence ◽  
Drug Resistant ◽  
Carbapenem Resistant ◽  
Therapeutic Regime ◽  
Drug Resistant Strains

Abstract Background. The emergence of multidrug and extensive drug resistant strains of Acinetobacter baumannii‎ is a multifactorial consequence. Carbapenems, once considered the traditional standard of care for Acinetobacter infections however, are gradually being curtailed from the therapeutic regime due to the emergence of Carbapenem resistant Acinetobacter baumannii‎ (CRAB). Several carbapenem resistant mechanisms have been postulated for the rise of CRAB. This study investigated clinical A.baumannii isolates for the presence and level of expression of enzymatic and non-enzymatic genes, putatively associated with carbapenem resistance and their association with sequence typing. Methods. Uniplex, and Multiplex PCR were performed to identify the presence of oxacillinase (OXA) and metallo β-lactamase (MBLs) genes respectively. The level of expression of efflux pumps (adeB and adeJ) and porins (carO, omp33-36 and oprD) was investigated by Real-time PCR. Results. Of the 112 isolates obtained during this study, 100% were multidrug-resistant and 48.2% were extensive drug-resistant A.baumannii. All CRAB isolates harbored blaOXA−51−like, while, 82.1% and 63.4% of these isolates carried blaOXA−23−like and blaOXA−24/40−like genes, respectively. In contrast, the frequency of metallo β-lactamase genes was comparatively less than the oxacillinase genes. Over-expression of adeB and adeJ was observed in 66% and 42.8% A.baumannii strains respectively, while, decreased expression of carO, omp33-36 and oprD was observed in 75%, 66% and 72.3% strains respectively. Conclusion. Consistent with that reported by others, our study highlights the significant dissemination of the oxacillinase, blaOXA−23−like in CRAB isolates, particularly the simultaneous occurrence of blaOXA−23−like with blaOXA−40. Interestingly, while changes in the expression of efflux pumps and porins were observed nevertheless, more in depth investigation is required to decipher their contribution to carbapenem resistance in these strains.

scholarly journals Molecular Epidemiology of Carbapenem-Resistant Acinetobacter baumannii Isolates from Northern Africa and the Middle East

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 291
Author(s):  
Paul G. Higgins ◽  
Ralf Matthias Hagen ◽  
Bernd Kreikemeyer ◽  
Philipp Warnke ◽  
Andreas Podbielski ◽  
...  
Keyword(s):  
Middle East ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Core Genome ◽  
Carbapenem Resistance ◽  
Resistance Mechanisms ◽  
Northern Africa ◽  
Carbapenem Resistant ◽  
Next Generation Sequencing Ngs ◽  
Injured Patients

At the Bundeswehr Hospitals of Hamburg and Westerstede, patients repatriated from subtropical war and crisis zones of Northern Africa and the Middle East were medically treated, including microbiological assessment. Within a six-year interval, 16 Acinetobacter spp. strains, including 14 Acinetobacter baumannii (Ab) isolates with resistance against carbapenems and origins in Afghanistan (n = 4), Iraq (n = 2), Libya (n = 2), and Syria (n = 8) were collected. While clonal relationships of Libyan and Syrian strains had been assessed by superficial next generation sequencing (NGS) and “DiversiLab” repetitive elements sequence-based (rep-)PCR so far, this study provides core genome-based sequence typing and thus more detailed epidemiological information. In detail, sequencing allowed a definitive species identification and comparison with international outbreak-associated Ab strains by core genome multi locus sequence typing (cgMLST) and the identification of MLST lineages, as well as the identification of known resistance genes. The sequence analysis allowed for the confirmation of outbreak-associated clonal clusters among the Syrian and Afghan Ab isolates, indicating likely transmission events. The identified acquired carbapenem resistance genes comprised blaOXA-23, blaOXA-58, blaNDM-1, and blaGES-11, next to other intrinsic and acquired, partly mobile resistance-associated genes. Eleven out of 14 Ab isolates clustered with the previously described international clonal lineages IC1 (4 Afghan strains), IC2 (6 Syrian strains), and IC7 (1 Syrian strain). Identified Pasteur sequence types of the 14 Ab strains comprised ST2 (Syrian), ST25 (Libyan), ST32 (Iraqi), ST81 (Afghan), ST85 (Libyan), and ST1112 (Syrian), respectively. In conclusion, the study revealed a broad spectrum of resistance genes in Ab isolated from war-injured patients from Northern Africa and the Middle East, thereby broadening the scarcely available data on locally abundant clonal lineages and resistance mechanisms.

scholarly journals In Vitro Double and Triple Bactericidal Activities of Doripenem, Polymyxin B, and Rifampin against Multidrug-Resistant Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli

2010 ◽  
Vol 54 (6) ◽  
pp. 2732-2734 ◽  
Author(s):  
Carl Urban ◽  
Noriel Mariano ◽  
James J. Rahal
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Carbapenem Resistance ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Carbapenem Resistant ◽  
Bactericidal Activities

ABSTRACT In vitro double and triple bactericidal activities of doripenem, polymyxin B, and rifampin were assessed against 20 carbapenem-resistant clinical isolates with different mechanisms of carbapenem resistance. Bactericidal activity was achieved in 90% of all bacteria assayed using combinations of polymyxin B, doripenem, and rifampin against five each of the carbapenem-resistant Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli isolates studied. Combinations with these antibacterials may provide a strategy for treatment of patients infected with such organisms.

scholarly journals Antimicrobial Resistance Mechanisms and Virulence of Colistin- and Carbapenem-Resistant Acinetobacter baumannii Isolated from a Teaching Hospital in Taiwan

2021 ◽  
Vol 9 (6) ◽  
pp. 1295
Author(s):  
Noor Andryan Ilsan ◽  
Yuarn-Jang Lee ◽  
Shu-Chen Kuo ◽  
I-Hui Lee ◽  
Tzu-Wen Huang
Keyword(s):  
Acinetobacter Baumannii ◽  
Teaching Hospital ◽  
Lipid A ◽  
Signal Transduction Pathway ◽  
Carbapenem Resistance ◽  
Resistance Mechanisms ◽  
Colistin Resistance ◽  
Carbapenem Resistant ◽  
Carbapenemase Gene ◽  
Significant Difference

Acinetobacter baumannii, a Gram-negative bacterium, is an important nosocomial pathogen. Colistin-resistant A. baumannii is becoming a new concern, since colistin is one of the last-line antibiotics for infections by carbapenem-resistant A. baumannii. From 452 carbapenem-resistant isolates collected in a teaching hospital in Taipei, Taiwan, we identified seven that were resistant to colistin. Carbapenem resistance in these isolates is attributed to the presence of carbapenemase gene blaOXA-23 in their genomes. Colistin resistance is presumably conferred by mutations in the sensor kinase domain of PmrB found in these isolates, which are known to result in modification of colistin target lipid A via the PmrB–PmrA–PmrC signal transduction pathway. Overexpression of pmrC, eptA, and naxD was observed in all seven isolates. Colistin resistance mediated by pmrB mutations has never been reported in Taiwan. One of the seven isolates contained three mutations in lpxD and exhibited an altered lipopolysaccharide profile, which may contribute to its colistin resistance. No significant difference in growth rates was observed between the isolates and the reference strain, suggesting no fitness cost of colistin resistance. Biofilm formation abilities of the isolates were lower than that of the reference. Interestingly, one of the isolates was heteroresistant to colistin. Four of the isolates were significantly more virulent to wax moth larvae than the reference.

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