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

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%) bla(OXA-72) (bla(OXA-24-like)); 28 (33.3%) bla(OXA-23-like) (20 bla(OXA-23) and 8 bla(OXA-225)); 18 (21.5%) bla(OXA-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 bla(OXA-58), one of which, Ajun-H1-3, isolated in a blood culture in January 2004, also possessed bla(NDM-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: see text] [Figure: see text] 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 bla(OXA-23-like) and bla(OXA-24-like) genes replacing bla(OXA-58). Among 19 NbA, an A. junii isolated in 2004 carried two carbapenemases, bla(OXA-58) and bla(NDM-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 bla(NDM) 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.