The number of infections caused by resistant organisms is largely unknown. We estimated the number of infections worldwide that are caused by the WHO priority pathogens third-generation cephalosporin-resistant and carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. We calculated a uniform weighted mean incidence of serious infections caused by antibiotic-susceptible E coli and K pneumoniae using data from 17 countries. Using this uniform incidence, as well as population sizes and country-specific resistance levels, we estimated the number of infections caused by third-generation cephalosporin-resistant and carbapenem-resistant E coli and K pneumoniae in 193 countries in 2014. We also calculated interval estimates derived from changing the fixed incidence of susceptible infections to 1 SD below and above the weighted mean. We compared an additive model with combination models in which resistant infections were replaced by susceptible infections. We distinguished between higher-certainty regions (those with good-quality data sources for resistance levels and resistance ≤30%), moderate-certainty regions (those with good-quality data sources for resistance levels and including some countries with resistance >30%), and low-certainty regions (those in which good-quality data sources for resistance levels were unavailable for countries comprising at least 20% of the region's population, regardless of resistance level). Using the additive model, we estimated that third-generation cephalosporin-resistant E coli and K pneumoniae caused 6·4 million (interval estimate 3·5-9·2) bloodstream infections and 50·1 million (27·5-72·8) serious infections in 2014; estimates were 5·5 million (3·0-7·9) bloodstream infections and 43·1 million (23·6-62·2) serious infections in the 25% replacement model, 4·6 million (2·5-6·6) bloodstream infections and 36·0 million (19·7-52·2) serious infections in the 50% replacement model, and 3·7 million (2·0-5·3) bloodstream infections and 28·9 million (15·8-41·9) serious infections in the 75% replacement model. Carbapenem-resistant strains caused 0·5 million (0·3-0·7) bloodstream infections and 3·1 million (1·8-4·5) serious infections based on the additive model, 0·5 million (0·3-0·7) bloodstream infections and 3·0 million (1·7-4·3) serious infections based on the 25% replacement model, 0·4 million (0·2-0·6) bloodstream infections and 2·8 million (1·6-4·1) serious infections based on the 50% replacement model, and 0·4 million (0·2-0·6) bloodstream infections and 2·7 million (1·5-3·8) serious infections based on the 75% replacement model. To our knowledge, this study is the first to report estimates of the global number of infections caused by antibiotic-resistant priority pathogens. Uncertainty stems from scant data on resistance levels from low-income and middle-income countries and insufficient knowledge regarding resistance dynamics when resistance is high. Innovative Medicines Initiative.

Infections caused by extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) are on a constant rise and are a noted cause of outbreaks in neonatal intensive care units (NICUs). We used whole genome sequencing (WGS) to investigate the epidemiology of consecutive and overlapping outbreaks caused by ESBL-KP in NICUs in three hospitals in close proximity. Clonality of 43 ESBL-KP isolates from 40 patients was determined by BOX-PCR. Short-read sequencing was performed on representative isolates from each clone. The dominant clones from each NICU were sequenced using long-read sequencing. Bioinformatics methods were used to define multilocus sequence type (MLST), analyze plasmid content, resistomes, and virulence factors. In each NICU, we found a unique dominant clone (ST985, ST37, and ST35), each belonging to a distinct sequence type (ST), as well as satellite clones. A satellite strain in NICU-2 (ST35) was the dominant strain in NICU-3, where it was isolated four weeks later, suggesting transmission. NICU-1- and NICU-2-dominant strains had bla_CTX-M-15 carried on a similar transposable element (Tn3-ISEcp1) but at different locations: on a plasmid and on the chromosome, respectively. We concluded that the overlapping ESBL-KP outbreaks were a combination of clonal transmission within NICUs, possible transposable element transmission between NICUs, and repeated importation of ESBL-KP from the community.

Blood culturing, the most important diagnostic procedure in treating bacterial infections, comprises both clinical and laboratory processes and is one of the most essential tasks of the clinical microbiology laboratory.¹ The primary goals are maximum detection of true pathogens with minimal contamination and speedy delivery of results. Delays in blood culture (BC) results may delay the initiation of appropriate antibiotic treatment, increasing the risk of death.^2,3 Best practice standards have been proposed for various aspects of blood culturing^4-7; because it is a multistep process involving clinical, ancillary, and laboratory staff across many departments, there are multiple opportunities for failure to meet these standards. Neither clinicians nor microbiologists are solely responsible for overseeing the blood culturing process. As a result, deficiencies in the process may go unnoticed or, if they are noticed, it is unclear whose job it is to correct them. The aim of this study was to evaluate processes related to the diagnosis of bloodstream infection (BSI) in Israeli hospitals and compare them with best practices to detect possible system weaknesses.

Nationwide studies on hospital-onset bloodstream infections (HO-BSIs) are scarce. To describe incidence, mortality and antimicrobial resistance (AMR) of HO-BSI caused by eight sentinel bacteria in Israel, we used laboratory-based BSI surveillance data from 1 January 2018 to 31 December 2019. All hospitals reported positive blood cultures growing Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Streptococcus pneumoniae, Staphylococcus aureus, Enterococcus faecalis and Enterococcus faecium. We calculated HO-BSI incidence and 14-day, 30-day and 1-year mortality in adults. We performed multivariable logistic regression to identify predictors of 30-day mortality. The study included 6752 HO-BSI events: K. pneumoniae (1659, 22.1%), E. coli (1491, 19.8%), S. aureus (1315, 17.5%), P. aeruginosa (1175, 15.6%), E. faecalis (778, 10.4%), A. baumannii (654, 8.7%), E. faecium (405, 5.4%) and S. pneumoniae (43, 0.6%). Overall incidence was 2.84/1000 admissions (95% CI: 2.77–2.91) and 6.88/10,000 patient-days (95% CI: 6.72–7.05). AMR isolates accounted for 44.2% of events. Fourteen-day, thirty-day and one-year mortality were 30.6% (95% CI: 28.5%–32.8%), 40.2% (95% CI: 38.2%–42.1%) and 66.5% (95% CI: 64.7%–68.3%), respectively. Organisms with highest risk for 30-day mortality (compared with E. coli) were A. baumannii (OR 2.85; 95% CI: 2.3–3.55), E. faecium (OR 2.16; 95% CI: 1.66–2.79) and S. pneumoniae (OR 2.36; 95% CI: 1.21–4.59). Mortality was higher in AMR isolates (OR 1.57; 95% CI: 1.4–1.77). This study highlights the incidence, associated high mortality and important role of antibiotic resistance in HO-BSI.

We analyzed Israeli national data on antimicrobial susceptibility from bloodstream isolates collected between 2014 and 2017 and compared resistance proportions with those of Europe. The incidence of bloodstream infection (BSI) caused by most antibiotic-resistant organisms remained unchanged or decreased. An exception was increased incidence of BSI caused by third-generation cephalosporin-resistant Escherichia coli. Overall, resistance proportions were similar to those observed in southern Europe, with the exception of a lower proportion of carbapenem-resistant Klebsiella pneumoniae in Israel.