Acinetobacter baumannii Bloodstream Infections: A Nationwide Study in Israel.

Acinetobacter baumannii (Ab) bloodstream infections (BSIs) are a major public health concern and associated with high mortality. We describe the nationwide incidence, antimicrobial resistance, and mortality of Ab-BSI in Israel using laboratory-based BSI surveillance data from January 2018 to December 2019. During the study period, there were 971 Ab-BSI events (508 in 2018 and 463 in 2019), with an average annual incidence of 8.08/100,000 population. The median age of patients was 72 (IQR 62-83), and 56.4% were males. Two-thirds of Ab-BSI events were hospital-onset (HO), with median day of onset 16 (IQR 9-30). HO-BSI incidence was 0.62/10,000 patient-days (rate per 10,000 patient-days: 2.78, 1.17, and 0.2 for intensive care, medical, and surgical wards, respectively). Carbapenem susceptibility was 23.4%; 41.4% and 14.9% in community and HO events, respectively. The 14-day, 30-day, and 1-year mortality were 51.2%, 59.3%, and 81.4%, respectively. Carbapenem-resistant Ab-BSI were associated with a significantly higher 14-day, 30-day, and 1-year mortality (p < 0.001 for all). In the multivariable model, age (aHR 1.02) and carbapenem resistance (aHR 3.21) were independent predictors of 30-day mortality. In conclusion, Ab-BSIs pose a significant burden with high mortality, especially associated with antimicrobial resistance. Attention should be focused on prevention and improving treatment.

Carriage of vancomycin-resistant Enterococcus faecium in infants following an outbreak in the neonatal intensive care unit: time to clearance of carriage and use of molecular methods to detect colonization.

Among 46 infants colonized with vancomycin-resistant Enterococcus faecium during an outbreak in a neonatal intensive care unit, the estimated time until half had achieved clearance was 217 days. All 40 infants who completed follow-up cleared carriage by 1 year. No predictors of prolonged carriage (> 6 months) were identified.

Hospital-Onset Bloodstream Infections Caused by Eight Sentinel Bacteria: A Nationwide Study in Israel, 2018-2019.

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.

Large-scale WGS of carbapenem-resistant Acinetobacter baumannii isolates reveals patterns of dissemination of ST clades associated with antibiotic resistance.

OBJECTIVES: To describe the population genetics and antibiotic resistance gene distribution of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates causing infections in three Mediterranean countries. METHODS: Isolates were collected during the 2013-17 AIDA clinical trial in six hospitals in Israel, Greece and Italy. WGS, bioinformatic characterization and antibiotic resistance profiling were performed. RESULTS: In the 247 CRAB isolates characterized in this study, ST distribution varied by country: 29/31 (93.5%) Greek isolates, 34/41 (82.9%) Italian isolates and 70/175 (40.0%) Israeli isolates belonged to ST2. The identified ST2 isolates included eight distinct clades: 2C, 2D and 2H were significantly more common in Italy, while 2F was unique to Greece. The uncommon ST3 was not present among Greek isolates and constituted only 5/41 (12%) Italian isolates. On the other hand, it was much more common among Israeli isolates: 78/175 (44.6%) belonged to ST3. The vast majority of isolates, 240/247 (97.2%), were found to harbour acquired carbapenemases, primarily blaOXA-23. The chromosomal oxaAb (blaOXA-51-like) and ampC genes characteristic of this organism were also ubiquitous. Most (96.4%) ST3 isolates carried a broad-host-range plasmid IncP1α. CONCLUSIONS: The geographical differences in CRAB populations support the theory that clonal spread of CRAB leads to endemicity in hospitals and regions. The close association between antibiotic resistance genes and clades, and between plasmids and STs, suggest that de novo creation of MDR A. baumannii is rare. The clustering of antibiotic resistance genes and plasmids that is unique to each clade/ST, and nearly uniform within clades/STs, suggests that horizontal transmission is rare but crucial to the clade's/ST's success.

A nationwide population-based study of Escherichia coli bloodstream infections: incidence, antimicrobial resistance and mortality.

OBJECTIVES: Escherichia coli is the leading cause of bloodstream infection (BSI). The incidence of E. coli BSI caused by antibiotic-resistant strains is increasing. We aimed to describe the nationwide incidence and resistance profile of E. coli BSI in Israel and its impact on mortality, to compare E. coli BSI mortality with all-cause mortality, and community-onset with hospital-onset E. coli BSIs. METHODS: We used mandatory BSI surveillance reports submitted by all Israeli hospitals to the Ministry of Health and the national death registry. All E. coli BSIs from 1 January 2018 to 31 December 31 2019 in patients aged 18 and over were included. RESULTS: A total of 11 113 E. coli BSIs occurred in 10 218 patients; 85% (9012/10 583) were community onset. Median age was 76 (IQR 65-85), and 57% (6304/11 113) of cases occurred in women. The annual incidence was 92.5 per 100 000 population. Antibiotic resistance was frequent and significantly more common in hospital-onset than in community-onset BSI; 65% (1021/1571) vs. 45% (4049/9012) were multidrug-resistant (MDR) (p < 0.001). The case fatality rate (CFR) was higher following hospital-onset BSI than community-onset: 23% (276/1214) vs. 12% (926/7620) at 14 days, 31% (378/1214) vs. 16% (1244/7620) at 30 days, and 55% (418/766) vs. 34% (1645/4903) at 1 year (p < 0.001 for all comparisons). The 1-year CFR was 47% (1258/2707) for MDR vs. 28% (928/3281) for non-MDR (p < 0.001). The annual mortality rate was 31.0 per 100 000 population, comprising 4.2% (31.0/734.8) of all causes of deaths. DISCUSSION: E. coli BSI carries a high burden, with a large proportion of MDR isolates, which are associated with increased incidence and CFR.