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

Grisold, Andrea; Luxner, Josefa; Bedenić, Branka; Diab-Elschahawi, Magda; Berktold, Michael; Wechsler-Fördös, Agnes; Zarfel, Gernot

doi:10.3390/ijerph18042171

Cited by 9 publications

(6 citation statements)

References 59 publications

(71 reference statements)

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“…It seems that the same resistance determinants as in previous studies, were carried by new STs, demonstrating the ability of A. baumannii to change the population structure but keep the same CHDL. The dominant MLST clonal complex in this study was CC208, this agrees with its dominant or strong presence in Europe and other parts of the world [53,54]. On the other hand, the results from India identified K. pneumoniae as the dominant pathogen in seriously ill COVID-19 patients [2].…”

Section: Discussionsupporting

confidence: 87%

Multidrug-Resistant Bacteria in a COVID-19 Hospital in Zagreb

et al. 2023

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During November to December 2020, a high rate of COVID-19-associated pneumonia with bacterial superinfections due to multidrug-resistant (MDR) pathogens was recorded in a COVID-19 hospital in Zagreb. This study analyzed the causative agents of bacterial superinfections among patients with serious forms of COVID-19. In total, 118 patients were hospitalized in the intensive care unit (ICU) of the COVID-19 hospital. Forty-six out of 118 patients (39%) developed serious bacterial infection (VAP or BSI or both) during their stay in ICU. The total mortality rate was 83/118 (70%). The mortality rate due to bacterial infection or a combination of ARDS with bacterial superinfection was 33% (40/118). Six patients had MDR organisms and 34 had XDR (extensively drug-resistant). The dominant species was Acinetobacter baumannii with all isolates (34) being carbapenem-resistant (CRAB) and positive for carbapenem-hydrolyzing oxacillinases (CHDL). One Escherichia coli causing pneumonia harboured the blaCTX-M-15 gene. It appears that the dominant resistance determinants of causative agents depend on the local epidemiology in the particular COVID center. Acinetobacter baumannii seems to easily spread in overcrowded ICUs. Croatia belongs to the 15 countries in the world with the highest mortality rate among COVID-19 patients, which could be in part attributable to the high prevalence of bacterial infections in local ICUs.

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Section: Discussionsupporting

confidence: 87%

Multidrug-Resistant Bacteria in a COVID-19 Hospital in Zagreb

et al. 2023

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“…Acinetobacter spp. isolates have shown a complex interaction of multiple mechanisms of resistance to carbapenems, with the production of naturally occurring oxacillinases (carbapenem-hydrolyzing class D ß-lactamases, CHDLs), grouped into closely related enzymes [33]. While A. baumannii harbors OXA-51 (OXA-51-Like Group), a chromosomebased enzyme intrinsic to the species, other CHDLs are acquired.…”

Section: Introductionmentioning

confidence: 99%

A Variant Carbapenem Inactivation Method (CIM) for Acinetobacter baumannii Group with Shortened Time-to-Result: rCIM-A

Mitteregger¹,

Wessely²,

Barišić

et al. 2022

Pathogens

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Carbapenem-resistant Acinetobacter baumannii group organisms (CRAB) are challenging because the choice between targeted, new antibiotic drug options and hygiene measures should be guided by a timely identification of resistance mechanisms. In CRAB, acquired class-D carbapenemases (CHDLs) are active against meropenem and imipenem. If PCR methods are not the first choice, phenotypic methods have to be implemented. While promising, the carbapenemase inactivation method (CIM) using meropenem-hydrolysis is, however, hampered by poor performance or overly long time-to-result. We developed a rapid CIM (rCIM-A) with good performance using ertapenem, imipenem, and meropenem disks, 2-h permeabilization and incubation with the test strain in trypticase soy broth, and a read-out of residual carbapenem activity after 6 h, and optionally after 16–18 h. Using clinical isolates and type-strains of Acinetobacter (n = 67) not harboring carbapenemases (n = 28) or harboring acquired carbapenemases (n = 39), the sensitivity of detection was 97.4% with the imipenem disk after 6 h at a specificity of 92.9%. If the inhibition zone around the ertapenem disk at 6 h was 6 or ≤26 mm at 16–18 h, or ≤25.5 mm for meropenem, the specificity was 100%. Because of the high negative predictive value, the rCIM-A seems particularly appropriate in areas of lower CRAB-frequency.

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“…In a recent study carried out in Nepal’s tertiary care hospital, of the 177 A. baumannii studied, nearly 91% of them exhibited carbapenem resistance ( Devkota et al, 2020 ). Grisold et al (2021) recently reported that among the 114 A. baumannii isolates characterized, 97.4 and 98.2% were resistant to imipenem and meropenem, whereas 88.6% exhibited multidrug resistance. As per the ICMR-AMRSN data, 45% of hospital-acquired infections are due to Acinetobacter spp., with higher non-susceptibilities to imipenem (82.2%) followed by meropenem (78.3%), cefepime, and ceftazidime (87%) ( Muthuirulandi Sethuvel et al, 2019 ).…”

Section: Introductionmentioning

confidence: 99%

Genotypic and Phenotypic Characterization of Novel Sequence Types of Carbapenem-Resistant Acinetobacter baumannii, With Heterogeneous Resistance Determinants and Targeted Variations in Efflux Operons

2021

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Acinetobacter baumannii has emerged as one of the dominant nosocomial human pathogens associated with high morbidity and mortality globally. Increased incidences of carbapenem-resistant A. baumannii (CRAB) have resulted in an enormous socioeconomic burden on health-care systems. Here, we report the genotypic and phenotypic characterization of novel ST1816 and ST128 variants in A. baumannii strains belonging to International clone II (GC2) with capsule types KL1:OCL8 and KL3:OCL1d from India. Sequence analysis revealed the presence of diverse virulome and resistome in these clinical strains, in addition to islands, prophages, and resistance genes. The oxacillinase blaOXA–23detected in the genomic island also highlighted the coexistence of blaOXA–66/blaOXA–98, blaADC73/blaADC–3, and blaTEM–1D in their mobile scaffolds, which is alarming. Together with these resistance-determining enzymes, multidrug efflux transporters also harbored substitutions, with increased expression in CRAB strains. The hotspot mutations in colistin resistance-conferring operons, PmrAB, LpxACD, and AdeRS, were additionally confirmed. Phenotype microarray analysis indicated that multidrug-resistant strains A. baumannii DR2 and A. baumannii AB067 preferred a range of antimicrobial compounds as their substrates relative to the other. To our knowledge, this is the first comprehensive report on the characterization of A. baumannii variants ST1816 and ST128, with different genetic makeup and genome organization. The occurrence of CRAB infections worldwide is a severe threat to available limited therapeutic options; hence, continued surveillance to monitor the emergence and dissemination of such novel ST variants in A. baumannii is imperative.

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

Cited by 9 publications

References 59 publications

Multidrug-Resistant Bacteria in a COVID-19 Hospital in Zagreb

Multidrug-Resistant Bacteria in a COVID-19 Hospital in Zagreb

A Variant Carbapenem Inactivation Method (CIM) for Acinetobacter baumannii Group with Shortened Time-to-Result: rCIM-A

Genotypic and Phenotypic Characterization of Novel Sequence Types of Carbapenem-Resistant Acinetobacter baumannii, With Heterogeneous Resistance Determinants and Targeted Variations in Efflux Operons

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