Tn7382, a novel composite transposon harboring blaNDM-1 and aphA6 in Acinetobacter baumannii

Hamed, Samira M.; Hussein, Amira F.A.; Al-Agamy, Mohamed H.; Radwan, Hesham H.; Zafer, Mai M.

doi:10.1016/j.jgar.2022.08.001

Cited by 10 publications

(10 citation statements)

References 12 publications

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“…Occasionally, a statistical significance was found between antimicrobial agents that belong to different classes. This is likely due to the co-existence of some resistance genes on the same plasmids or other mobile genetic elements [ 49 , 50 ]. It is worth mentioning that such associations were more frequently found among Gram-negative species ( Figure S1–S8 ).…”

Section: Discussionmentioning

confidence: 99%

“…No combinations of CR genes were found in E. coli or P. aeruginosa . Many studies have also noticed the co-existence of carbapenemase-coding genes, which resulted in decreased sensitivity to various antibiotics [ 49 , 54 , 55 , 56 ]. Interestingly, some of our isolates that carried one or more of the CR genes ( bla KPC , bla IMP , bla VIM , or bla NDM ) showed phenotypic susceptibility to imipenem.…”

Section: Discussionmentioning

confidence: 99%

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Phenotypic and Genotypic Analysis of Bacterial Pathogens Recovered from Patients Diagnosed with Fever of Unknown Origin in Egypt

Mostafa¹,

Saleh

Khaleel

et al. 2023

Antibiotics

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Fever of unknown origin (FUO) is a medical term describing fever that lasts for at least three weeks without a diagnosis being reached after extensive diagnostic evaluation. Therefore, this study aimed to identify the common pathogens causing FUO in patients admitted to Abbasia Fever Hospital in Egypt from January 2020 to December 2022, their antimicrobial susceptibility profiles, and associated resistance genes. The study also aimed to investigate the burden of multidrug-resistant (MDR) pathogens and the priority pathogens nominated by the World Health Organization (WHO) for posing the greatest threat to human health due to antibiotic resistance. During the study period, about 726 patients were diagnosed with FUO. After extensive investigations, the cause of the FUO was found to be infectious diseases in 479/726 patients (66.0%). Of them, 257 patients had positive bacterial cultures, including 202 Gram-negative isolates that comprised Klebsiella pneumoniae (85/202; 42.1%), Escherichia coli (71/202; 35.1%), Acinetobacter baumannii (26/202; 12.9%), and Pseudomonas aeruginosa (14/202; 6.9%) and 55 Gram-positive isolates, including Staphylococcus aureus (23/55; 41.8%), Streptococcus pneumoniae (7/55; 12.7%), and Enterococcus spp. (25/55; 45.5%). The MDR phenotype was shown by 68.3% and 65.5% of the Gram-negative and Gram-positive isolates, respectively. Carbapenem resistance (CR) was shown by 43.1% of the Gram-negative isolates. Of the 23 S. aureus isolates obtained from research participants, 15 (65.2%) were methicillin-resistant S. aureus (MRSA). A high-level aminoglycoside resistance (HLAR) phenotype was found in 52.0% of the Enterococcus sp. isolates. The PCR screening of resistance genes in the MDR isolates showed that blaOXA−48 was the most prevalent (84%) among the carbapenemase-coding genes, followed by blaVIM (9%) and then blaIMP (12%). The ESBL-coding genes blaTEM, blaCTX-M,aac(6′)-Ib, and blaSHV, were prevalent in 100%, 93.2%, 85,% and 53.4% of the MDR isolates, respectively. This study updates the range of bacteria that cause FUO and emphasizes the burden of multidrug resistance and priority infections in the region. The obtained data is of relevant medical importance for the implementation of evidence-based antimicrobial stewardship programs and tailoring existing empirical treatment guidelines.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Phenotypic and Genotypic Analysis of Bacterial Pathogens Recovered from Patients Diagnosed with Fever of Unknown Origin in Egypt

Mostafa¹,

Saleh

Khaleel

et al. 2023

Antibiotics

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“…BLAST searches of this transposon against the National Center for Biotechnology Information’s non-redundant nucleotide database revealed the presence of this transposon and its derivatives predominantly among A. baumannii and non- baumannii Acinetobacter species, but also in different plasmids and chromosomes of E. coli , K. pneumoniae , and other Enterobacterales. The bla NDM-1 context among the IC9 however had a different context – a truncated Tn 125 transposon captured within flanking ISAba14 direct repeats and recently named Tn 7382 58 . This transposon is only sparsely described in literature but is predominantly found among A. baumannii strains belonging to IC9 54,58 .…”

Section: Discussionmentioning

confidence: 99%

“…The bla NDM-1 context among the IC9 however had a different context – a truncated Tn 125 transposon captured within flanking ISAba14 direct repeats and recently named Tn 7382 58 . This transposon is only sparsely described in literature but is predominantly found among A. baumannii strains belonging to IC9 54,58 . The increased NDM-1 prevalence in our study and potential for intra- and inter-species spread has notable implications as this enzyme is very potent and has a wider spectrum of hydrolysis for beta-lactams and carbapenems compared to OXA-23 and OXA-58, thus grossly limiting the already limited number of treatment options for A. baumannii infections 59–62 .…”

Section: Discussionmentioning

confidence: 99%

High genetic diversity andbla_NDM-1prevalence amongAcinetobacter baumanniiin Nigerian hospitals

Odih

Oaikhena

Underwood

et al. 2023

Preprint

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Background: Acinetobacter baumannii cause difficult-to-treat infections mostly among immunocompromised patients. Clinically relevant A. baumannii lineages and their carbapenem resistance mechanisms are sparsely described in Nigeria. Objective: This study aimed to characterise the diversity and genetic mechanisms of carbapenem resistance among A. baumanniistrains isolated from hospitals in southwestern Nigeria. Methods: We sequenced the genomes of all A. baumannii isolates submitted to Nigeria's antimicrobial resistance surveillance reference laboratory between 2016 – 2020 on an Illumina platform and performed in silico genomic characterisation. Selected strains were sequenced using the Oxford Nanopore technology to characterise the genetic context of carbapenem resistance genes. Results: The 86 A. baumannii isolates were phylogenetically diverse and belonged to 35 distinct sequence types (STs), 16 of which were novel. Thirty-eight (44.2%) isolates belonged to none of the known international clones (ICs). Over 50% of the isolates were phenotypically resistant to 10 of 12 tested antimicrobials. Majority (n=54) of the isolates were carbapenem-resistant, particularly the IC7 (100%) and IC9 (>91.7%) strains. blaOXA-23(34.9%) and blaNDM-1(27.9%) were the most common carbapenem resistance genes detected. All blaOXA-23genes were carried on Tn2006 or Tn2006-like transposons. Our findings suggest that the mobilisation of a 10kb Tn125 composite transposon is the primary means of blaNDM-dissemination. Conclusion: Our findings highlight an increase in blaNDM-1prevalence and the widespread transposon-facilitated dissemination of carbapenemase genes in diverse A. baumannii lineages in southwestern Nigeria. We make the case for improving surveillance of these pathogens in Nigeria and other understudied settings.

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“…The intrinsic bla OXA-51 -like and bla ADC -like genes were also not reported. To determine the genetic contexts of the detected carbapenem resistance genes, we mapped both the assemblies and the reads of the wastewater isolates to previously characterized mobile genetic elements carrying acquired carbapenem resistance genes in A. baumannii ( 16 , 19 , 54 – 56 ) using Gview server ( https://server.gview.ca/ ) with default parameters (for the assemblies) and BWA MEM ( 57 ) version 0.7.17 (for the reads). Duplicate reads were marked and removed using Picard version 3.0.0 ( http://broadinstitute.github.io/picard ).…”

Section: Methodsmentioning

confidence: 99%

NDM-1- and OXA-23-producing Acinetobacter baumannii in wastewater of a Nigerian hospital

Odih,

Sunmonu,

Okeke

et al. 2023

Microbiol Spectr

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Carbapenem-resistant Acinetobacter baumannii spp. are increasingly important pathogens with limited treatment options, and there is limited knowledge on the environmental factors contributing to their spread. We determined the occurrence of carbapenem-resistant A. baumannii in hospital wastewater and their phylogenetic relationships with clinical A. baumannii isolates. Grab samples of raw and treated hospital wastewater were collected monthly at the University College Hospital, Ibadan, Nigeria, between March 2021 and February 2022. Acinetobacter baumannii strains were selectively isolated and identified using VITEK2, and their whole genomes were sequenced on an Illumina platform. We performed antimicrobial susceptibility testing and in silico genomic characterization of the strains and determined their phylogenetic relationships to previously characterized clinical A. baumannii strains from Nigeria. A. baumannii complex isolates were recovered from wastewater throughout the study. Of the 82 isolates identified based on whole-genome sequences, 77 were A. baumannii. A. baumannii isolates had high resistance rates (≥48.1%) to 10 of 12 antimicrobials tested, and majority (42/77, 54.5%) were resistant to carbapenems, with bla NDM-1 being the most common (24/77, 31.2%) carbapenem resistance gene detected, followed by bla OXA-23 ( n = 22, 28.6%). There was no statistically significant difference in carbapenem resistance rates or carbapenem gene carriage between the raw and treated wastewater isolates. Most of the isolates belonged to novel or sparsely described lineages, some of which were closely related to clinical isolates. The release of inadequately treated hospital wastewater into the environment may contribute to the increased spread of carbapenem-resistant and clinically important A. baumannii lineages in Ibadan, Nigeria. IMPORTANCE Acinetobacter baumannii is a leading cause of hospital-associated infections globally. A. baumannii reservoirs outside hospital settings are still unknown, and their occurrence in the environment is linked to clinical and anthropogenic activities. Although the risk of transmission of A. baumannii from environmental sources to humans is not fully understood, these sources pose significant risks for the continued dissemination of A. baumannii and their resistance traits. This study provides evidence that diverse and clinically relevant A. baumannii strains, many of which are resistant to carbapenems, are constantly being discharged into the environment through inadequately treated hospital wastewater. We further elucidate potential transmission routes between the environment and clinical infections and demonstrate the high prevalence of carbapenem resistance genes on highly mobile transposons among these strains. Our findings highlight the pressing need to address hospital wastewater as a crucial factor in curtailing the spread of carbapenem-resistant A. baumannii .

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Tn7382, a novel composite transposon harboring blaNDM-1 and aphA6 in Acinetobacter baumannii

Cited by 10 publications

References 12 publications

Phenotypic and Genotypic Analysis of Bacterial Pathogens Recovered from Patients Diagnosed with Fever of Unknown Origin in Egypt

Phenotypic and Genotypic Analysis of Bacterial Pathogens Recovered from Patients Diagnosed with Fever of Unknown Origin in Egypt

High genetic diversity andbla_NDM-1prevalence amongAcinetobacter baumanniiin Nigerian hospitals

NDM-1- and OXA-23-producing Acinetobacter baumannii in wastewater of a Nigerian hospital

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Tn7382, a novel composite transposon harboring blaNDM-1 and aphA6 in Acinetobacter baumannii

Cited by 10 publications

References 12 publications

Phenotypic and Genotypic Analysis of Bacterial Pathogens Recovered from Patients Diagnosed with Fever of Unknown Origin in Egypt

Phenotypic and Genotypic Analysis of Bacterial Pathogens Recovered from Patients Diagnosed with Fever of Unknown Origin in Egypt

High genetic diversity andblaNDM-1prevalence amongAcinetobacter baumanniiin Nigerian hospitals

NDM-1- and OXA-23-producing Acinetobacter baumannii in wastewater of a Nigerian hospital

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High genetic diversity andbla_NDM-1prevalence amongAcinetobacter baumanniiin Nigerian hospitals