scholarly journals 154. comparative Genomics Reveals Extra-hospital Transmission Networks of Carbapenem-resistant acinetobacter Baumannii sustained over Multiple Years in a US Midwest City

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S206-S206
Author(s):  
Juan J Calix ◽  
Maria Claudia Stockler de Almeida ◽  
Robert Potter ◽  
Meghan Wallace ◽  
Carey-Ann Burnham ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Acinetobacter Baumannii ◽  
Chart Review ◽  
Genetic Relatedness ◽  
Transmission Dynamics ◽  
Transmission Networks ◽  
Hospital Outbreak ◽  
Carbapenem Resistant ◽  
Hospital Environments ◽  
Hospital Transmission

Abstract Background The transmission dynamics of Acinetobacter baumannii (Ab) outside the setting of hospital outbreaks is underinvestigated. The BJC Healthcare System in St. Louis, MO has not experienced an Ab hospital outbreak since 2012. Despite this, nearly 60% of all BJC Ab isolates are carbapenem-resistant Ab (CrAb). Methods We acquired whole genome sequences (WGSs) of 110 Ab isolates identified in five BJC hospitals from July 2017 to May 2019. We performed multilocus sequence typing, core genome alignment and pairwise average nucleotide identity analysis to compare WGSs from BJC isolates and GenBank-available WGSs of Ab isolates from other US hospitals. Further epidemiologic characterization was performed using BJC electronic medical records and detailed chart review. Results Though the majority of CrAb isolates in other US studies belonged to globally-prevalent sequence type 2 (ST2 [Pasteur scheme]), 62% and 26% of BJC CrAb index isolates belonged to the unrelated ST499 and ST406, respectively. BJC ST499 and ST406 isolates were phylogenetically distinct compared to corresponding isolates from other US hospitals. Under the assumption that Ab transmission occurs primarily through nosocomial spread, we expected BJC isolates from the same hospital and timespan to share the highest degree of homogeneity. However, geotemporal proximity between ST499 or ST406 BJC isolates was a poor predictor of their genetic relatedness, according to multiple comparative methods. Review of patient metadata did not identify epidemiological links between BJC isolates within phylogenetic subgroups. Conclusion We combined comparative genomics and detailed clinical chart review to characterize the transmission dynamics of two emerging US CrAb sequence types, ST499 and ST406. Though these highly homogeneous Ab isolates were identified over two years in multiple BJC hospitals, we found no evidence of robust intra-hospital transmission networks. Instead, it appears that these CrAb isolates independently emerged from yet-to-be-identified regional, extra-hospital Ab populations. To neutralize the threat of drug-resistant infections in the US, it is essential to identify, characterize and disrupt emergent CrAb transmission networks that exist outside of hospital environments. Disclosures All Authors: No reported disclosures

scholarly journals Whole-Genome Sequencing for Investigating a Health Care-Associated Outbreak of Carbapenem-Resistant Acinetobacter baumannii

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 201
Author(s):  
Sang Mee Hwang ◽  
Hee Won Cho ◽  
Tae Yeul Kim ◽  
Jeong Su Park ◽  
Jongtak Jung ◽  
...  
Keyword(s):  
Whole Genome Sequencing ◽  
Acinetobacter Baumannii ◽  
Genome Sequencing ◽  
Snp Analysis ◽  
Whole Genome ◽  
Phylogenetic Tree Analysis ◽  
Web Based ◽  
Hospital Outbreak ◽  
Carbapenem Resistant ◽  
Bioinformatics Tools

Carbapenem-resistant Acinetobacter baumannii (CRAB) outbreaks in hospital settings challenge the treatment of patients and infection control. Understanding the relatedness of clinical isolates is important in distinguishing outbreak isolates from sporadic cases. This study investigated 11 CRAB isolates from a hospital outbreak by whole-genome sequencing (WGS), utilizing various bioinformatics tools for outbreak analysis. The results of multilocus sequence typing (MLST), single nucleotide polymorphism (SNP) analysis, and phylogenetic tree analysis by WGS through web-based tools were compared, and repetitive element polymerase chain reaction (rep-PCR) typing was performed. Through the WGS of 11 A. baumannii isolates, three clonal lineages were identified from the outbreak. The coexistence of blaOXA-23, blaOXA-66, blaADC-25, and armA with additional aminoglycoside-inactivating enzymes, predicted to confer multidrug resistance, was identified in all isolates. The MLST Oxford scheme identified three types (ST191, ST369, and ST451), and, through whole-genome MLST and whole-genome SNP analyses, different clones were found to exist within the MLST types. wgSNP showed the highest discriminatory power with the lowest similarities among the isolates. Using the various bioinformatics tools for WGS, CRAB outbreak analysis was applicable and identified three discrete clusters differentiating the separate epidemiologic relationships among the isolates.

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 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 Co-infection of ST2IP carbapenem-resistant Acinetobacter baumannii with SARS-CoV-2 in the patients admitted to a Tehran tertiary referral hospital

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Alireza Abdollahi ◽  
Amir Aliramezani ◽  
Mohammadreza Salehi ◽  
Mahsa Norouzi Shadehi ◽  
Sedighe Ghourchian ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Genetic Relatedness ◽  
Carbapenem Resistance ◽  
Underlying Disease ◽  
Referral Hospital ◽  
Clinical Samples ◽  
Tertiary Referral ◽  
Tertiary Referral Hospital ◽  
Carbapenem Resistant ◽  
High Level

Abstract Background Carbapenem-resistant Acinetobacter baumannii (CRAB) is among the most concerning cause of healthcare-associated infections (HAI) due to its high level of antibiotic resistance and high mortality. In the era of the COVID-19 pandemic, the key priority of infection control committees is to contain the dissemination of antibiotic resistant Gram-negative bacteria. Here, we aimed to timely recognize the emergence of CRAB in COVID-19 cases admitted to the wards of a tertiary referral hospital and to identify the genetic relatedness of the isolates. Methods From 30 March to 30 May 2020, a total of 242 clinical samples from COVID-19 cases were screened for CRAB isolates using standard microbiologic and antibiotic susceptibility tests. The PCRs targeting oxa23, oxa24, oxa58, blaTEM and blaNDM-1 genes were performed. Two multiplex PCRs for identifying the global clones (GC) of A. baumannii were also performed. The sequence type of CRABs was determined using Institut Pasteur (IP) multilocus sequence typing (MLST) scheme. Results Eighteen CRAB isolates were recovered from COVID-19 patients with the mean age of 63.94 ± 13.8 years. All but 4 COVID-19 patients co-infected with CRAB were suffering from an underlying disease. Death was recorded as the outcome in ICUs for 9 (50%) COVID-19 patients co-infected with CRAB. The CRAB isolates belong to GC2 and ST2IP and carried the oxa23 carbapenem resistance gene. Conclusion This study demonstrated the co-infection of CRAB isolates and SARS-CoV-2 in the patients admitted to different ICUs at a referral hospital in Tehran. The CRAB isolates were found to belong to ST2IP, share the oxa23 gene and to have caused several outbreaks in the wards admitting COVID-19 patients.

scholarly journals Molecular characterization and antibiotic resistance of Acinetobacter baumannii in cerebrospinal fluid and blood

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247418
Author(s):  
Xiaohong Shi ◽  
Hong Wang ◽  
Xin Wang ◽  
Huaiqi Jing ◽  
Ran Duan ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Infection Control ◽  
Acinetobacter Baumannii ◽  
Detection Rate ◽  
Genetic Relatedness ◽  
Treatment Options ◽  
Carbapenem Resistance ◽  
Control Measures ◽  
Carbapenem Resistant ◽  
Carbapenemase Gene

The increasing prevalence of carbapenem-resistant Acinetobacter baumannii (CRAB) caused nosocomial infections generate significant comorbidity and can cause death among patients. Current treatment options are limited. These infections pose great difficulties for infection control and clinical treatment. To identify the antimicrobial resistance, carbapenemases and genetic relatedness of Acinetobacter baumannii isolates from cerebrospinal fluid (CSF) and blood, a total of 50 nonrepetitive CSF isolates and 44 blood isolates were collected. The resistance phenotypes were determined, and polymerase chain reaction (PCR) was performed to examine the mechanisms of carbapenem resistance. Finally, multilocus sequence typing (MLST) was conducted to determine the genetic relatedness of these isolates. It was observed that 88 of the 94 collected isolates were resistant to imipenem or meropenem. Among them, the blaOXA-23 gene was the most prevalent carbapenemase gene, with an observed detection rate of 91.5% (86/94), followed by the blaOXA-24 gene with a 2.1% detection rate (2/94). Among all carbapenem-resistant Acinetobacter baumannii (CRAB) observations, isolates with the blaOXA-23 gene were resistant to both imipenem and meropenem. Interestingly, isolates positive for the blaOXA-24 gene but negative for the blaOXA-23 gene showed an imipenem-sensitive but meropenem-resistant phenotype. The MLST analysis identified 21 different sequence types (STs), with ST195, ST540 and ST208 most frequently detected (25.5%, 12.8% and 11.7%, respectively). 80 of the 94 isolates (85.1%) were clustered into CC92 which showed a carbapenem resistance phenotype (except AB13). Five novel STs were detected, and most of them belong to CRAB. In conclusion, these findings provide additional observations and epidemiological data of CSF and blood A. baumannii strains, which may improve future infection-control measures and aid in potential clinical treatments in hospitals and other clinical settings.

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