131. Carbapenemase-producing Acinetobacter spp. from Israel, 2001-2006: earliest report of blaNDM predating the oldest known blaNDM-positive strains

Abstract Background Carbapenem-resistant Acinetobacter baumannii (CRAb) is a WHO priority 1 critical pathogen. Despite Israel being affected early by high CRAb rates, limited molecular data are available. We investigated the presence of carbapenemases among 198 Acinetobacter spp. clinical isolates from Israel between 2001 and 2006. Methods Strains from 3 archives underwent whole-genome sequencing (Illumina NovaSeq on all, MinION on a subset) and computational analyses: assembly (Unicycler), annotation (prokka), identification (Kraken, 16S rRNA), search for carbapenemases (ResFinder, BLDB curation). Figures were generated in Inkscape, plasmid alignment on AliTV. Results A. baumannii (Ab) represented 179/198 (90.4%) Acinetobacter spp. (Figure 1). Annual incidence varied from a minimum of 16 (2001) to a maximum of 62 (2004), with an average of 30. Eighty-four Ab (46.9%) carried a carbapenemase: 38 (45.2%) blaOXA-72 (blaOXA-24-like); 28 (33.3%) blaOXA-23-like (20 blaOXA-23 and 8 blaOXA-225); 18 (21.5%) blaOXA-58 (16 from 2001-2). Annual CRAb rate increased yearly from 2002 (32%) to 2006 (67%). Eight species of non-baumannii Acinetobacter (NbA) accounted for 19 isolates (9.6%): A. pittii (n=6), lwoffii (n=4), junii (n=3), ursingii (n=2), others n=1: A. gyllenbergii, johnsonnii, schindleri, and variabilis (Figure 1). Two of three A. junii contained blaOXA-58, one of which, Ajun-H1-3, isolated in a blood culture in January 2004, also possessed blaNDM-1. The pNDM-Ajun-H1-3 plasmid matched numerous NDM-positive plasmids reported from 2005 onwards in Acinetobacter spp. as well as Enterobacterales (Figure 2). Figure 1:annual distribution of Acinetobacter baumannii and non-baumannii Acinetobacter in Israel between 2001 and 2006, including their intrinsic oxacillinases and the presence of carbapenemases.Figure 2:plasmid alignment of pNDM-Ajun-H1-3 (Israel, 2004) with other NDM-positive plasmids found globally from 2005 onwards in Acinetobacter spp. and Enterobacterales. Conclusion We retrospectively assessed carbapenemase diversity among Acinetobacter spp. in Israel from 2001-2006. Analysis of 179 Ab isolates predate observations elsewhere: rapidly rising CRAb rates, driven by the dissemination of blaOXA-23-like and blaOXA-24-like genes replacing blaOXA-58. Among 19 NbA, an A. junii isolated in 2004 carried two carbapenemases, blaOXA-58 and blaNDM-1, making it the earliest NDM-positive isolate reported to date, preceding NDM-positive Acinetobacter spp. found in 2005 in India. Further investigations into the origins of blaNDM are needed to understand the conditions that led to its emergence and prevent similar issues from arising in the future. Disclosures Paul G. Higgins, PhD, Coris Bioconcept: Supply antibodies for lateral flow test kits.