Multicity Outbreak of Carbapenem-Resistant Acinetobacter baumannii Isolates Producing the Carbapenemase OXA-40

ABSTRACT During 2005 we detected a multicity outbreak of infections or colonization due to high-level imipenem-resistant Acinetobacter baumannii (MIC, 64 μg/ml). One hundred isolates from diverse sources were obtained from seven acute-care hospitals and two extended-care facilities; 97% of the isolates belonged to one clone. Susceptibility testing of the first 42 isolates (January to April 2005) revealed broad resistance profiles. Half of the isolates were susceptible to ceftazidime, with many isolates susceptible only to colistin. The level of AmpC β-lactamase expression was stronger in isolates resistant to ceftazidime. PCR and subsequent nucleotide sequencing analysis identified bla OXA-40. The presence of an OXA-40 β-lactamase in these isolates correlated with the carbapenem resistance. By Southern blot analysis, a bla OXA-40-specific probe revealed that the gene was both plasmid and chromosomally located. This is the first time in the United States that such carbapenem resistance in A. baumannii has been attributable to a carbapenemase.

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Antibiotic Susceptibility, Clonality, and Molecular Characterization of Carbapenem-Resistant Clinical Isolates of Acinetobacter baumannii from Washington DC

International Journal of Microbiology ◽

10.1155/2020/2120159 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Garima Bansal ◽

Rachelle Allen-McFarlane ◽

Broderick Eribo

Keyword(s):

Acinetobacter Baumannii ◽

Multiplex Pcr ◽

Antibiotic Susceptibility ◽

Carbapenem Resistance ◽

The United States ◽

Pcr Analysis ◽

Washington Dc ◽

Antibiotic Resistant ◽

Group 4 ◽

Carbapenem Resistant

The occurrence of carbapenem-resistant (CR) strains of Acinetobacter baumannii is reported to contribute to the severity of several nosocomial infections, especially in critically ill patients in intensive care units. The present study aims to determine the antibiotic susceptibility, clonality, and genetic mechanism of carbapenem resistance in twenty-eight Acinetobacter baumannii isolates from four hospitals in Washington DC. The antibiotic susceptibility of the isolates was determined by VITEK 2 analyses, while PCR was used to examine the presence of antibiotic-resistant genes and mobile genetic elements. Trilocus multiplex-PCR was used along with pulsed-field gel electrophoresis (PFGE) for strain typing and for accessing clonal relationships among the isolates. Antimicrobial susceptibility testing indicated that 46% of the isolates were carbapenem-resistant and possessed MDR and XDR phenotypes. PFGE clustered the 28 isolates into seven clonal (C1–C7) complexes based on >75% similarity cut-off. Thirty-six percent of the isolates belonged to international clone II, while 29% were assigned to Group 4 by trilocus multiplex-PCR. Although the blaOXA-51-like gene was found in all the isolates, only 36% were positive for the blaOXA-23-like gene. PCR analysis also found a metallo-β-lactamase (MBL) gene (blaVIM) in 71% of the isolates. Of the 13 CR isolates, 8 were PCR positive for both blaVIM and blaOXA-23-like genes, while 5 harbored only blaVIM gene. This study revealed the emergence of VIM carbapenemase-producing A. baumannii isolates, which has not been previously reported in the United States.

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Genetic Factors Associated with Elevated Carbapenem Resistance in KPC-Producing Klebsiella pneumoniae

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00008-10 ◽

2010 ◽

Vol 54 (10) ◽

pp. 4201-4207 ◽

Cited By ~ 93

Author(s):

Brandon Kitchel ◽

J. Kamile Rasheed ◽

Andrea Endimiani ◽

Andrea M. Hujer ◽

Karen F. Anderson ◽

...

Keyword(s):

United States ◽

Klebsiella Pneumoniae ◽

Copy Number ◽

Gene Copy Number ◽

Carbapenem Resistance ◽

The United States ◽

Gene Copy ◽

Sequencing Analysis ◽

Low Level ◽

High Level

ABSTRACT In the United States, the most prevalent mechanism of carbapenem resistance among Enterobacteriaceae is the production of a Klebsiella pneumoniae carbapenemase (KPC). KPC-producing isolates often exhibit a range of carbapenem MICs. To better understand the factors that contribute to overall carbapenem resistance, we analyzed 27 KPC-producing K. pneumoniae isolates with different levels of carbapenem resistance, 11 with low-level (i.e., meropenem or imipenem MIC ≤ 4 μg/ml), 2 with intermediate-level (i.e., meropenem and imipenem MIC = 8 μg/ml), and 14 with high-level (i.e., imipenem or meropenem MIC ≥ 16 μg/ml) carbapenem resistance, that were received from throughout the United States. Among 14 isolates that exhibited high-level carbapenem resistance, Western blot analysis indicated that 10 produced an elevated amount of KPC. These isolates either contained an increased bla KPC gene copy number (n = 3) or had deletions directly upstream of the bla KPC gene (n = 7). Four additional isolates lacked elevated KPC production but had high-level carbapenem resistance. Porin sequencing analysis identified 22 isolates potentially lacking a functional OmpK35 and three isolates potentially lacking a functional OmpK36. The highest carbapenem MICs were found in two isolates that lacked both functioning porins and produced elevated amounts of KPC. The 11 isolates with low-level carbapenem resistance contained neither an upstream deletion nor increased bla KPC copy number. These results suggest that both bla KPC copy number and deletions in the upstream genetic environment affect the level of KPC production and may contribute to high-level carbapenem resistance in KPC-producing K. pneumoniae, particularly when coupled with OmpK36 porin loss.

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

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18042171 ◽

2021 ◽

Vol 18 (4) ◽

pp. 2171 ◽

Cited By ~ 1

Author(s):

Andrea Grisold ◽

Josefa Luxner ◽

Branka Bedenić ◽

Magda Diab-Elschahawi ◽

Michael Berktold ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Genetic Background ◽

Regional Differences ◽

Carbapenem Resistance ◽

Carbapenem Resistant ◽

Class D ◽

Acinetobacter Spp ◽

First Time ◽

Sequence Types ◽

Significant Health

Carbapenem-resistant Acinetobacter baumannii is a significant health problem worldwide. A multicenter study on A. baumannii was performed to investigate the molecular epidemiology and genetic background of carbapenem resistance of A. baumannii isolates collected from 2014–2017 in Austria. In total, 117 non-repetitive Acinetobacter spp. assigned to A. baumannii (n = 114) and A. pittii (n = 3) were collected from four centers in Austria. The isolates were uniformly resistant to piperacillin/tazobactam, ceftazidime, and carbapenems, and resistance to imipenem and meropenem was 97.4% and 98.2%, respectively. The most prominent OXA-types were OXA-58-like (46.5%) and OXA-23-like (41.2%), followed by OXA-24-like (10.5%), with notable regional differences. Carbapenem-hydrolyzing class D carbapenemases (CHDLs) were the only carbapenemases found in A.baumannii isolates in Austria since no metallo-β-lactamases (MBLs) nor KPC or GES carbapenemases were detected in any of the isolates. One-third of the isolates harbored multiple CHDLs. The population structure of A. baumannii isolates from Austria was found to be very diverse, while a total of twenty-three different sequence types (STs) were identified. The most frequent was ST195 found in 15.8%, followed by ST218 and ST231 equally found in 11.4% of isolates. Two new ST types, ST2025 and ST2026, were detected. In one A. pittii isolate, blaOXA-143-like was detected for the first time in Austria.

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

BMC Infectious Diseases ◽

10.1186/s12879-021-06642-2 ◽

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.

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Types and Prevalence of Carbapenem-Resistant Acinetobacter calcoaceticus-Acinetobacter baumannii Complex in Northern Taiwan

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00779-13 ◽

2013 ◽

Vol 58 (1) ◽

pp. 201-204 ◽

Cited By ~ 12

Author(s):

Wen-Shyang Hsieh ◽

Nai-Yu Wang ◽

Jou-An Feng ◽

Li-Chuan Weng ◽

Hsueh-Hsia Wu

Keyword(s):

Acinetobacter Baumannii ◽

Medical Center ◽

Carbapenem Resistance ◽

Acinetobacter Calcoaceticus ◽

Pulsed Field Gel Electrophoresis ◽

Content Type ◽

Carbapenem Resistant ◽

Acinetobacter Baumannii Complex ◽

High Level ◽

Northern Taiwan

ABSTRACTThe frequency of the carbapenem-resistantAcinetobacter calcoaceticus-Acinetobacter baumannii(CRACB) complex increases annually in our hospitals. However, the types and prevalence of carbapenemases among isolates still remain unclear. In this study, we identified and collected 672 carbapenem-resistant isolates from a medical center in Northern Taiwan between April and December of 2010. There were 577 genospecies 2 (Acinetobacter baumannii), 79 genospecies 13TU, and 16 genospecies 3 isolates. The isolates had an acquiredblaOXA-24-like gene, which was confirmed by sequencing for the encoded OXA-72 carbapenemase, and were often associated with high-level carbapenem resistance. These CRACB complex isolates remained susceptible to colistin (100%). The genotyping of isolates was conducted using pulsed-field gel electrophoresis with ApaI digestion. In most clonally related groups, patients were from both branch hospitals. The results indicate that interhospital dissemination of clones occurred. This study provides updated data on the types and prevalence of the CRACB complex. In addition, it presents a warning on the emergence and spread of CRACB complex harboringblaOXA-24-like genes in northern Taiwan.

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Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii from Southern Brazil

Revista de Epidemiologia e Controle de Infecção ◽

10.17058/reci.v1i1.15017 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Gabriel De Paula Gollino ◽

Bruna Machado Escobar ◽

Ilson Dias da Silveira ◽

Rosa Helena Robales Siqueira ◽

Joseane Cristina Ferreira ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Carbapenem Resistance ◽

Polymyxin B ◽

Border Region ◽

Molecular Profile ◽

Carbapenem Resistant ◽

Class D ◽

Western Border ◽

South Of Brazil ◽

High Level

Carbapenem resistance in Acinetobacter baumannii has reached extremely high levels worldwide and class D OXA-type carbapenemases are the main associated mechanism. The aim of this study was to evaluate the phenotypic and molecular profile of clinical carbapenem-resistant A. baumannii (CRAb) isolates from a southern Brazilian border region. A. baumannii species was identified by the presence of the blaOXA-51 gene and the susceptibility profile was determined by broth microdilution. The main carbapenemases were investigated by PCR and the typing of the CRAb isolates was performed by PFGE. During the study period, a total of 36 CRAb were recovered, 71.4% from respiratory tract samples from ICU patients. High level resistance to aminoglycosides and fluroquinolones were found in contrast to polymyxin B, for which all of CRAb were susceptible. The blaOXA-23 gene was present in 34 isolates and was the only one detected other than blaOXA-51. Molecular typing revealed the presence of four clonal strains, two of them endemic throughout the study period. To the best of our knowledge, our study brings the first data about resistance profile in Acinetobacter in the western border of south of Brazil and make aware of endemic clones of CRAb-producing-OXA-23 in this region of state, contributing for the construction of the national epidemiologic scenario of CRAb.

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Emergence of Carbapenem-Resistant Non-baumannii Species of Acinetobacter Harboring ablaOXA-51-Like Gene That Is Intrinsic to A. baumannii

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00622-11 ◽

2011 ◽

Vol 56 (2) ◽

pp. 1124-1127 ◽

Cited By ~ 59

Author(s):

Yi-Tzu Lee ◽

Shu-Chen Kuo ◽

Mei-Chun Chiang ◽

Su-Pen Yang ◽

Chien-Pei Chen ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Carbapenem Resistance ◽

Content Type ◽

Carbapenem Resistant ◽

Genomic Species ◽

High Level

ABSTRACTTheblaOXA-51-like gene, originally intrinsic toAcinetobacter baumannii, had been detected in two clones ofAcinetobacter nosocomialisand one clone ofAcinetobactergenomic species “Close to 13TU.” TheseblaOXA-51-like genes, all preceded by ISAba1, were located on plasmids that might have originated withA. baumannii. The plasmid-borne ISAba1--blaOXA-51-like confers a high level of carbapenem resistance and affects the accuracy of usingblaOXA-51-like detection as a tool for differentiatingA. baumanniifrom otherAcinetobacterspecies.

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Emergence and Distribution of Plasmids Bearing the blaOXA-51-Like Gene with an Upstream ISAba1 in Carbapenem-Resistant Acinetobacter baumannii Isolates in Taiwan

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00764-10 ◽

2010 ◽

Vol 54 (11) ◽

pp. 4575-4581 ◽

Cited By ~ 79

Author(s):

Te-Li Chen ◽

Yi-Tzu Lee ◽

Shu-Chen Kuo ◽

Po-Ren Hsueh ◽

Feng-Yee Chang ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Copy Number ◽

Recombinant Plasmid ◽

Gene Dosage ◽

Carbapenem Resistance ◽

Carbapenem Resistant ◽

Genomic Species ◽

High Level

ABSTRACT The bla OXA-51-like gene with an upstream ISAba1 (ISAba1-bla OXA-51-like gene) was originally found on the chromosomes of carbapenem-resistant or -susceptible Acinetobacter baumannii isolates. However, a plasmid-borne ISAba1-bla OXA-51-like gene has recently been identified in Acinetobacter genomic species 13TU and several A. baumannii isolates in Taiwan, and all of the isolates are carbapenem resistant. This study aimed to characterize the plasmids bearing the ISAba1-bla OXA-51-like gene and their significance in A. baumannii. Among the 117 ISAba1-bla OXA-51-like-harboring isolates collected from 10 hospitals in Taiwan, 58 isolates (49.6%) from 24 clones had the genes located on plasmids that likely originated from a common progenitor. Among the 58 isolates, four had additional copy of the ISAba1-bla OXA-51-like gene on their chromosomes. Based on the analysis of these four isolates, the plasmid-located ISAba1-bla OXA-51-like gene appeared to be acquired via one-ended transposition (Tn6080). The isolates with a plasmid bearing the ISAba1-bla OXA-51-like gene had higher rates of resistance to imipenem (98% versus 46.6%; P < 0.001) and meropenem (98% versus 69%; P = 0.019) than those with the genes chromosomally encoded, which is most likely due to increased gene dosage provided by the higher copy number of associated plasmids. Transformation with a recombinant plasmid harboring only the ISAba1-bla OXA-51-like gene was enough to confer a high level of carbapenem resistance to A. baumannii, eliminating the possible contribution of other factors on the original plasmids. This study demonstrated that the carbapenem resistance-associated plasmids carrying the ISAba1-bla OXA-51-like gene are widespread in A. baumannii strains in Taiwan.

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PREVALENCE OF CARBAPENEM-RESISTANT ACINETOBACTER BAUMANNII (CRAB) IN MEDICAL AND SURGICAL INTENSIVE CARE UNITS (ICUS) OF JPMC, KARACHI

Pakistan Journal of Medicine and Dentistry ◽

10.36283/pjmd8-4/006 ◽

2019 ◽

Author(s):

Rabia Arshad

Keyword(s):

Intensive Care ◽

Antimicrobial Resistance ◽

Acinetobacter Baumannii ◽

Intensive Care Units ◽

Carbapenem Resistance ◽

Chronic Obstructive ◽

Surgical Intensive Care ◽

Carbapenem Resistant ◽

Number Of Patients ◽

Increased Risk

Background: Antimicrobial resistance is one of the research priorities of health organizations due to increased risk of morbidity and mortality. Outbreaks of nosocomial infections caused by carbapenem-resistant Acinetobacter Baumannii (CRAB) strains are at rise worldwide. Antimicrobial resistance to carbapenems reduces clinical therapeutic choices and frequently led to treatment failure. The aim of our study was to determine the prevalence of carbapenem resistance in A. baumannii isolated from patients in intensive care units (ICUs). Methods: This cross-sectional study was carried out in the Department of Microbiology, Basic Medical Sciences Institute (BMSI), Jinnah Postgraduate Medical Centre (JPMC), Karachi, from December 2016 to November 2017. Total 63 non-repetitive A. baumannii were collected from the patients’ specimens, admitted to medical and surgical ICUs and wards of JPMC, Karachi. The bacterial isolates were processed according to standard microbiological procedures to observe for carbapenem resistance. SPSS 21 was used for data analysis. Results: Out of the 63 patients, 40 (63.5%) were male. The age of the patient ranged from 15-85 year, with average of 43 year. 34.9% patients had been hospitalized for 3 days. Chronic obstructive pulmonary disease was present in highest number with average of 58.7% for morbidity. Number of patients on mechanical ventilation was highest (65.1%). All isolates were susceptible to colistin. The resistance to ampicillin-sulbactam, ceftazidime, ciprofloxacin, amikacin, piperacillin- tazobactam and meropenem was 82.5%, 81%, 100%, 87.3%, 82.5% and 82% respectively. Out of 82% CRAB, 77% were obtained from ICUs. Conclusion: This study has revealed the high rate of carbapenem resistance in A. baumannii isolates in ICUs thus leaving behind limited therapeutic options.

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Multicenter Clinical and Molecular Epidemiological Analysis of Bacteremia Due to Carbapenem-Resistant Enterobacteriaceae (CRE) in the CRE Epicenter of the United States

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02349-16 ◽

2017 ◽

Vol 61 (4) ◽

Cited By ~ 98

Author(s):

Michael J. Satlin ◽

Liang Chen ◽

Gopi Patel ◽

Angela Gomez-Simmonds ◽

Gregory Weston ◽

...

Keyword(s):

New York ◽

Empirical Therapy ◽

Carbapenem Resistance ◽

The United States ◽

Resistance Mechanisms ◽

Rapid Diagnostics ◽

Multicenter Studies ◽

Content Type ◽

Medical Centers ◽

Carbapenem Resistant

ABSTRACT Although the New York/New Jersey (NY/NJ) area is an epicenter for carbapenem-resistant Enterobacteriaceae (CRE), there are few multicenter studies of CRE from this region. We characterized patients with CRE bacteremia in 2013 at eight NY/NJ medical centers and determined the prevalence of carbapenem resistance among Enterobacteriaceae bloodstream isolates and CRE resistance mechanisms, genetic backgrounds, capsular types (cps), and antimicrobial susceptibilities. Of 121 patients with CRE bacteremia, 50% had cancer or had undergone transplantation. The prevalences of carbapenem resistance among Klebsiella pneumoniae, Enterobacter spp., and Escherichia coli bacteremias were 9.7%, 2.2%, and 0.1%, respectively. Ninety percent of CRE were K. pneumoniae and 92% produced K. pneumoniae carbapenemase (KPC-3, 48%; KPC-2, 44%). Two CRE produced NDM-1 and OXA-48 carbapenemases. Sequence type 258 (ST258) predominated among KPC-producing K. pneumoniae (KPC-Kp). The wzi154 allele, corresponding to cps-2, was present in 93% of KPC-3-Kp, whereas KPC-2-Kp had greater cps diversity. Ninety-nine percent of CRE were ceftazidime-avibactam (CAZ-AVI)-susceptible, although 42% of KPC-3-Kp had an CAZ-AVI MIC of ≥4/4 μg/ml. There was a median of 47 h from bacteremia onset until active antimicrobial therapy, 38% of patients had septic shock, and 49% died within 30 days. KPC-3-Kp bacteremia (adjusted odds ratio [aOR], 2.58; P = 0.045), cancer (aOR, 3.61, P = 0.01), and bacteremia onset in the intensive care unit (aOR, 3.79; P = 0.03) were independently associated with mortality. Active empirical therapy and combination therapy were not associated with survival. Despite a decade of experience with CRE, patients with CRE bacteremia have protracted delays in appropriate therapies and high mortality rates, highlighting the need for rapid diagnostics and evaluation of new therapeutics.

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