Multidrug-Resistant and Extensively Drug-Resistant Acinetobacter baumannii Causing Nosocomial Meningitis in the Neurological Intensive Care Unit

Abstract

Acinetobacter baumannii is one of the significant healthcare-associated meningitis agents characterized by multidrug resistance and a high mortality risk. Thirty-seven A. baumannii strains were isolated from thirty-seven patients of Moscow neuro-ICU with meningitis in 2013–2020. The death rate was 37.8%. Strain susceptibility to antimicrobials was determined on the Vitek-2 instrument. Whole-genome sequencing was conducted using Illumina technology; the sequence types (ST), capsular types (KL), lipooligosaccharide outer core locus (OCL), antimicrobial resistance genes, and virulence genes were identified. The prevalent ST was ST2, belonging to the international clone IC2, and rarer, ST1, ST19, ST45, ST78, ST106, and ST400, with prevalence of KL9 and OCL1. Twenty-nine strains belonged to multidrug-resistant (MDR) and eight extensively drug-resistant (XDR) categories. Genes conferring resistance to beta-lactams (blaPER, blaGES, blaADC, blaCARB, blaCTX-M, blaTEM, and blaOXA-types), aminoglycosides (aac, aad, ant, aph, and arm), tetracyclines (tet), macrolides (msr and mph), phenicols (cml, cat, and flo), sulfonamides (dfr and sul), rifampin (arr), and antiseptics (qac) were identified. Virulence genes of nine groups (Adherence, Biofilm formation, Enzymes, Immune evasion, Iron uptake, Regulation, Serum resistance, Stress adaptation, and Antiphagocytosis) were detected. The study highlights the heterogeneity in genetic clones, antimicrobial resistance, and virulence genes variability among the agents of A. baumannii meningitis, with the prevalence of the dominant international clone IC2.

Detection of carbapenemase producing Acinetobacter baumannii ST19 from Georgia and Ukraine carrying blaOXA-23, blaOXA-72, and/or blaNDM-5, December 2019 to June 2023

“…Nevertheless, GC complexes also include other lineages. One of these is ST19, a single locus variant of the ST1/GC1 clone, that has scarcely been reported globally [6,[17][18][19][20]. At the time of the current study, we could find only 11 non-redundant genomes for A. baumannii ST19 in the GenBank database and, to the best of our knowledge, just five published reports of studies relating to this ST [6,[17][18][19][20].…”

“…One of these is ST19, a single locus variant of the ST1/GC1 clone, that has scarcely been reported globally [6,[17][18][19][20]. At the time of the current study, we could find only 11 non-redundant genomes for A. baumannii ST19 in the GenBank database and, to the best of our knowledge, just five published reports of studies relating to this ST [6,[17][18][19][20]. The first of these articles, published in 2015, described the detection of four ST19 isolates from hospital surfaces in Algeria, carrying bla NDM-5 [17].…”

“…Between 2003 and 2023, 97 multidrug resistant (MDR) Acinetobacter baumannii isolates of sequence type (ST) 19 were identified through the Multidrug-Resistant Organism Repository and Surveillance Network (MRSN) at the Walter Reed Army Institute of Research (WRAIR) in the United States (US) [1,2]. We here describe these ST19 MDR isolates, conduct phylogenomic analyses together with 11 non-redundant ST19 genomes available in GenBank, and raise awareness on the increasing number of carbapenemase-producing ST19 detected in Georgia and Ukraine between 2019 and 2023.…”

New Antibiotics for the Treatment of Nosocomial Central Nervous System Infections

“…Since most highly resistant pneumococci and staphylococci are still susceptible to vancomycin and linezolid, and vancomycin-resistant enterococci are usually susceptible to linezolid [1,2], at present, Gram-negative bacteria (in particular Acinetobacter baumannii and Klebsiella spp.) constitute the greatest threat to patients suffering from nosocomial meningitis and ventriculitis [3,4]. Gram-negative bacteria resistant to fourth-generation cephalosporins, piperacillin/tazobactam, fluoroquinolones, and carbapenems are termed multidrug-resistant (MDR), and, in the case of an additional resistance to polymyxins, they are termed extensively drug-resistant (XDR).…”

A multiplex RPA coupled with CRISPR-Cas12a system for rapid and cost-effective identification of carbapenem-resistant Acinetobacter baumannii

“…This characteristic allows it to persist in various hospital settings, imposing unnecessary burdens on the healthcare system in terms of diagnosis, logistics, and finances ( Doughty et al, 2023 ). A. baumannii is a clinically significant nosocomial pathogen, and human infections with this bacterium can lead to complications such as meningitis ( Fursova et al, 2023 ), bacteremia ( Hong et al, 2023 ; Nutman et al, 2023 ) and ventilator-associated pneumonia ( Riddles and Judge, 2023 ). Notably, A. baumannii is most commonly encountered in intensive care units (ICU) and critically ill patients, where infections contribute significantly to organ failure and sepsis, representing primary causes of patient mortality ( Blanco et al, 2018 ; Seok et al, 2021 ).…”