Extensively Drug-Resistant Pseudomonas aeruginosa Outbreak Associated With Artificial Tears.

BACKGROUND: Carbapenemase-producing, carbapenem-resistant Pseudomonas aeruginosa (CP-CRPA) are extensively drug-resistant bacteria. We investigated the source of a multistate CP-CRPA outbreak. METHODS: Cases were defined as a US patient's first isolation of P. aeruginosa sequence type 1203 with carbapenemase gene blaVIM-80 and cephalosporinase gene blaGES-9 from any specimen source collected and reported to the Centers for Disease Control and Prevention during 1 January 2022-15 May 2023. We conducted a 1:1 matched case-control study at the post-acute care facility with the most cases, assessed exposures associated with case status for all case-patients, and tested products for bacterial contamination. RESULTS: We identified 81 case-patients from 18 states, 27 of whom were identified through surveillance cultures. Four (7%) of 54 case-patients with clinical cultures died within 30 days of culture collection, and 4 (22%) of 18 with eye infections underwent enucleation. In the case-control study, case-patients had increased odds of receiving artificial tears versus controls (crude matched OR, 5.0; 95% CI, 1.1-22.8). Overall, artificial tears use was reported by 61 (87%) of 70 case-patients with information; 43 (77%) of 56 case-patients with brand information reported use of Brand A, an imported, preservative-free, over-the-counter (OTC) product. Bacteria isolated from opened and unopened bottles of Brand A were genetically related to patient isolates. Food and Drug Administration inspection of the manufacturing plant identified likely sources of contamination. CONCLUSIONS: A manufactured medical product serving as the vehicle for carbapenemase-producing organisms is unprecedented in the United States. The clinical impacts from this outbreak underscore the need for improved requirements for US OTC product importers.

Application of whole-genome sequencing for norovirus outbreak tracking and surveillance efforts in Orange County, CA.

Noroviruses are the leading cause of acute gastroenteritis and foodborne illness in the United States. Traditional Sanger sequencing of short genomic regions (~300-600 bp) is the primary method for differentiation of this pathogen; however, whole-genome sequencing (WGS) offers a valuable approach to further characterize strains of this virus. The objective of this study was to investigate the ability of WGS compared to Sanger sequencing to differentiate norovirus strains and enhance outbreak investigation and surveillance efforts. WGS results for 41 norovirus-positive stool samples from 15 different outbreaks occurring from 2012 to 2019 in Orange County, CA, were analyzed for this study. All samples were genotyped with both WGS and Sanger sequencing based on the B-C region. WGS generated nearly full-length viral genome sequences (7029-7768 bp) with 4x to 35,378x coverage. Phylogenetic analysis of WGS data enabled differentiation of genotypically similar strains from separate outbreaks. Single nucleotide variation (SNV) analysis on a subset of strains revealed nucleotide variations (15-79 nt) among isolates from multiple outbreaks of GII.4 Sydney_2015[P31] and GII.17[P17]. Overall, the results demonstrated that coupling norovirus genotype identification with WGS enables enhanced genetic differentiation of strains and provides valuable information for outbreak investigation and surveillance efforts.