Clinical and microbiological characteristics of bloodstream infection caused by Klebsiella pneumoniae harboring rmpA in Japanese adults.

We investigated the clinical features of bloodstream infections (BSIs) caused by Klebsiella pneumoniae harboring rmpA and molecular characteristics of the bacteria. We retrospectively investigated adult patients with K. pneumoniae BSI from January 2010 to March 2021 at Nagasaki University Hospital. A matched case-control study in a 1:3 ratio was conducted to clarify the clinical and bacterial characteristics of BSI caused by rmpA-positive K. pneumoniae compared with those caused by rmpA-negative isolates. Antimicrobial susceptibility testing and multilocus sequence typing (MLST) were performed for rmpA-positive isolates. The rmpA was detected in 36 (13.4%) of the 268 isolates. Of these 36 isolates, 31 (86.1%) harbored iucA and 35 (97.2%) each possessed peg-344 and iroB; capsular types were identified as K1 in 9 (25.0%) and K2 in 10 isolates (27.8%). Contrarily, of the 108 rmpA-negative isolates, which were matched for case-control studies, 5 isolates (4.6%) harbored iucA and 1 (0.9%) each possessed peg-344 and iroB; 2 (1.9%) and 3 isolates (2.8%) had K1 and K2 capsular types, respectively. Among the rmpA-positive isolates, ST23/K1 (eight isolates) was the most frequent, followed by ST412/non-K1/K2 (seven isolates), ST86/K2 (five isolates), and ST268/non-K1/K2 (four isolates). In a multivariate analysis using clinical factors, liver abscess positively correlated with rmpA-positive isolates, whereas biliary tract infection and use of anticancer drugs negatively correlated with rmpA-positive isolates in patients with K. pneumoniae BSI. Considering the correlation between rmpA-positive isolates and clinical features, rmpA can be used as a marker for understanding the pathophysiology of K. pneumoniae BSI.

Evaluation of the Neonatal Sequential Organ Failure Assessment and Mortality Risk in Preterm Infants With Late-Onset Infection.

Importance: Infection in neonates remains a substantial problem. Advances for this population are hindered by the absence of a consensus definition for sepsis. In adults, the Sequential Organ Failure Assessment (SOFA) operationalizes mortality risk with infection and defines sepsis. The generalizability of the neonatal SOFA (nSOFA) for neonatal late-onset infection-related mortality remains unknown. Objective: To determine the generalizability of the nSOFA for neonatal late-onset infection-related mortality across multiple sites. Design, Setting, and Participants: A multicenter retrospective cohort study was conducted at 7 academic neonatal intensive care units between January 1, 2010, and December 31, 2019. Participants included 653 preterm (<33 weeks) very low-birth-weight infants. Exposures: Late-onset (>72 hours of life) infection including bacteremia, fungemia, or surgical peritonitis. Main Outcomes and Measures: The primary outcome was late-onset infection episode mortality. The nSOFA scores from survivors and nonsurvivors with confirmed late-onset infection were compared at 9 time points (T) preceding and following event onset. Results: In the 653 infants who met inclusion criteria, median gestational age was 25.5 weeks (interquartile range, 24-27 weeks) and median birth weight was 780 g (interquartile range, 638-960 g). A total of 366 infants (56%) were male. Late-onset infection episode mortality occurred in 97 infants (15%). Area under the receiver operating characteristic curves for mortality in the total cohort ranged across study centers from 0.71 to 0.95 (T0 hours), 0.77 to 0.96 (T6 hours), and 0.78 to 0.96 (T12 hours), with utility noted at all centers and in aggregate. Using the maximum nSOFA score at T0 or T6, the area under the receiver operating characteristic curve for mortality was 0.88 (95% CI, 0.84-0.91). Analyses stratified by sex or Gram-stain identification of pathogen class or restricted to infants born at less than 25 weeks' completed gestation did not reduce the association of the nSOFA score with infection-related mortality. Conclusions and Relevance: The nSOFA score was associated with late-onset infection mortality in preterm infants at the time of evaluation both in aggregate and in each center. These findings suggest that the nSOFA may serve as the foundation for a consensus definition of sepsis in this population.

Presence of urinary symptoms in bacteremic urinary tract infection: a retrospective cohort study of Escherichia coli bacteremia.

BACKGROUND: It is important to understand clinical features of bacteremic urinary tract infection (bUTI), because bUTI is a serious infection that requires prompt diagnosis and antibiotic therapy. Escherichia coli is the most common and important uropathogen. The objective of our study was to characterize the clinical presentation of E coli bUTI. METHODS: Retrospective cohort study of consecutive adult patients admitted for community acquired E. coli bacteremia from January 1, 2015 to December 31, 2016 was conducted at 4 acute care academic and community hospitals in Toronto, Ontario, Canada. Logistic regression models were developed to identify E coli bUTI cases without urinary symptoms. RESULTS: Of 462 patients with E. coli bacteremia, 284 (61.5%) patients had a urinary source. Of these 284 patients, 161 (56.7%) had urinary symptoms. In a multivariable model, bUTI without urinary symptoms were associated with older age (age < 65 years as reference, age 65-74 years had OR of 2.13 95% CI 0.99-4.59 p = 0.0523; age 75-84 years had OR of 1.80 95% CI 0.91-3.57 p = 0.0914; age > =85 years had OR of 2.95 95% CI 1.44-6.18 p = 0.0036) and delirium (OR of 2.12 95% CI 1.13-4.03 p = 0.0207). Sepsis by SIRS criteria was present in 274 (96.5%) of all bUTI cases and 119 (96.8%) of bUTI cases without urinary symptoms. CONCLUSION: The majority of patients with E. coli bacteremia had a urinary source. A significant proportion of bUTI cases had no urinary symptoms elicited on history. Elderly and delirious patients were more likely to have bUTI without urinary symptoms. In elderly and delirious patients with sepsis by SIRS criteria but without a clear infectious source, clinicians should suspect, investigate, and treat for bUTI.

Infection as a Stroke Risk Factor and Determinant of Outcome After Stroke.

Understanding the relationship between infection and stroke has taken on new urgency in the era of the coronavirus disease 2019 (COVID-19) pandemic. This association is not a new concept, as several infections have long been recognized to contribute to stroke risk. The association of infection and stroke is also bidirectional. Although infection can lead to stroke, stroke also induces immune suppression which increases risk of infection. Apart from their short-term effects, emerging evidence suggests that poststroke immune changes may also adversely affect long-term cognitive outcomes in patients with stroke, increasing the risk of poststroke neurodegeneration and dementia. Infections at the time of stroke may also increase immune dysregulation after the stroke, further exacerbating the risk of cognitive decline. This review will cover the role of acute infections, including respiratory infections such as COVID-19, as a trigger for stroke; the role of infectious burden, or the cumulative number of infections throughout life, as a contributor to long-term risk of atherosclerotic disease and stroke; immune dysregulation after stroke and its effect on the risk of stroke-associated infection; and the impact of infection at the time of a stroke on the immune reaction to brain injury and subsequent long-term cognitive and functional outcomes. Finally, we will present a model to conceptualize the many relationships among chronic and acute infections and their short- and long-term neurological consequences. This model will suggest several directions for future research.

Sympathetic nerves control bacterial clearance.

A neural reflex mediated by the splanchnic sympathetic nerves regulates systemic inflammation in negative feedback fashion, but its consequences for host responses to live infection are unknown. To test this, conscious instrumented sheep were infected intravenously with live E. coli bacteria and followed for 48 h. A month previously, animals had undergone either bilateral splanchnic nerve section or a sham operation. As established for rodents, sheep with cut splanchnic nerves mounted a stronger systemic inflammatory response: higher blood levels of tumor necrosis factor alpha and interleukin-6 but lower levels of the anti-inflammatory cytokine interleukin-10, compared with sham-operated animals. Sequential blood cultures revealed that most sham-operated sheep maintained high circulating levels of live E. coli throughout the 48-h study period, while all sheep without splanchnic nerves rapidly cleared their bacteraemia and recovered clinically. The sympathetic inflammatory reflex evidently has a profound influence on the clearance of systemic bacterial infection.

Temperature Trajectory Subphenotypes Correlate With Immune Responses in Patients With Sepsis.

OBJECTIVES: We recently found that distinct body temperature trajectories of infected patients correlated with survival. Understanding the relationship between the temperature trajectories and the host immune response to infection could allow us to immunophenotype patients at the bedside using temperature. The objective was to identify whether temperature trajectories have consistent associations with specific cytokine responses in two distinct cohorts of infected patients. DESIGN: Prospective observational study. SETTING: Large academic medical center between 2013 and 2019. SUBJECTS: Two cohorts of infected patients: 1) patients in the ICU with septic shock and 2) hospitalized patients with Staphylococcus aureus bacteremia. INTERVENTIONS: Clinical data (including body temperature) and plasma cytokine concentrations were measured. Patients were classified into four temperature trajectory subphenotypes using their temperature measurements in the first 72 hours from the onset of infection. Log-transformed cytokine levels were standardized to the mean and compared with the subphenotypes in both cohorts. MEASUREMENTS AND MAIN RESULTS: The cohorts consisted of 120 patients with septic shock (cohort 1) and 88 patients with S. aureus bacteremia (cohort 2). Patients from both cohorts were classified into one of four previously validated temperature subphenotypes: "hyperthermic, slow resolvers" (n = 19 cohort 1; n = 13 cohort 2), "hyperthermic, fast resolvers" (n = 18 C1; n = 24 C2), "normothermic" (n = 54 C1; n = 31 C2), and "hypothermic" (n = 29 C1; n = 20 C2). Both "hyperthermic, slow resolvers" and "hyperthermic, fast resolvers" had high levels of G-CSF, CCL2, and interleukin-10 compared with the "hypothermic" group when controlling for cohort and timing of cytokine measurement (p < 0.05). In contrast to the "hyperthermic, slow resolvers," the "hyperthermic, fast resolvers" showed significant decreases in the levels of several cytokines over a 24-hour period, including interleukin-1RA, interleukin-6, interleukin-8, G-CSF, and M-CSF (p < 0.001). CONCLUSIONS: Temperature trajectory subphenotypes are associated with consistent cytokine profiles in two distinct cohorts of infected patients. These subphenotypes could play a role in the bedside identification of cytokine profiles in patients with sepsis.

Staphylococcus aureus Bacteremia: Contemporary Management.

Staphylococcus aureus bacteremia (SAB) is a serious cause of bloodstream infection associated with significant morbidity and mortality. Complications include deep-seated foci of infection including infective endocarditis, device-associated infection, osteoarticular metastases, pleuropulmonary involvement, and recurrent infection. With the 30-day all-cause mortality being around 20%, a collaborative effort of early Infectious Diseases (ID) consultation and Antimicrobial Stewardship Program (ASP) involvement will show improved SAB outcomes and therapy optimization.1.

The Effect of Antibiotic-Cycling Strategy on Antibiotic-Resistant Bacterial Infections or Colonization in Intensive Care Units: A Systematic Review and Meta-Analysis.

BACKGROUND: Antibiotic-resistant bacteria, especially multidrug-resistant strains, play a key role in impeding critical patients from survival and recovery. The effectiveness of the empiric use of antibiotics in the circling manner in intensive care units (ICUs) has not been analyzed in detail and remains controversial. Therefore, this systematic review and meta-analysis were conducted to evaluate antibiotic-cycling effect on the incidence of antibiotic-resistant bacteria. METHODS: We searched PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science for studies focusing on whether a cycling strategy of empiric use of antibiotics could curb the prevalence of antibiotic-resistant bacteria in ICUs. The major outcomes were risk ratios (RRs) of antibiotic-resistant infections or colonization per 1,000 patient days before and after the implementation of antibiotic cycling. A random-effects model was adopted to estimate results in consideration of clinical heterogeneity among studies. The registration number of the meta-analysis is CRD42018094464. RESULTS: Twelve studies, involving 2,261 episodes of resistant infections or colonization and 160,129 patient days, were included in the final analysis. Based on the available evidence, the antibiotic-cycling strategy did not reduce the overall incidence of infections or colonization with resistant bacteria (RR = 0.823, 95% CI 0.655-1.035, p = .095). In subgroup analyses, the cycling strategy cut down the incidence of resistant bacteria more significantly than baseline period (p = .028) but showed no difference in comparison with mixing strategy (p = .758). LINKING EVIDENCE TO ACTION: Although the cycling strategy performed better than relatively free usage of antibiotics in the baseline period on reducing resistant bacteria, the cycling strategy did not show advantage when compared with the mixing strategy in subgroup analyses. In addition, these viewpoints still need more evidence to confirm.

Colistin monotherapy versus colistin-based combination therapy for treatment of bacteremia in burn patients due to carbapenem-resistant gram negative bacteria.

Carbapenem-resistant gram negative pathogen (CR-GNP) infection in burn patients is a growing concern since treatment options are limited and resistance to the main line of treatment, colistin, is increasing. The goal of this study was to compare treatment outcomes of colistin monotherapy versus colistin-based combination therapy for CR-GNP bacteremia in burn patients. A retrospective observational study was conducted between 2014 and 2017 in Hangang Sacred Heart Hospital located in Seoul, South Korea. Among the burn patients admitted to the burn intensive care unit with CR-GNP bacteremia due to wound infections, colistin monotherapy or colistin-based combination therapy were investigated. We determined both eradication rate within seven days as well as mortality rate within 30 days. A total of 84 burn patients with CR-GNP bacteremia were analyzed-32 were treated with colistin monotherapy and 52 with colistin-based combination therapy. We found that eradication rate within 7 days and 30-day mortality rate were not significantly different between the two groups (71.9% versus 75.0%, P = 0.752 and 31.2% versus 38.5%, P = 0.503). In the Cox regression analysis, Charlson's comorbidity index, renal replacement therapy before colistin use, and duration of antibiotics were associated with 30-day mortality (HR, 1.23; 95% CI, 1.02-1.49; P = 0.030, HR, 2.28; 95% CI, 1.05-4.94; P = 0.037 and HR, 0.94; 95% CI, 0.89-0.99, P = 0.042, respectively). Colistin-based combination therapy did not show significant differences with regard to microbiologic and clinical outcomes compared with colistin monotherapy.

The Inflammatory and Hemostatic Response in Sepsis and Meningococcemia.

Meningococcemia is notorious for evasion of the host immune system and its rapid progression to fulminant disease, and serves as a unique model for pediatric sepsis. Illness severity is determined by complex interplays among host, pathogen, and environment. The inflammatory host response, including proinflammatory and anti-inflammatory responses in innate and adaptive immunity, skews toward a proinflammatory state. This leads to endothelial dysfunction and activation of the hemostatic response, which may lead to disseminated intravascular coagulation. This article reviews the pathogenesis of sepsis, in particular the inflammatory and hemostatic response in meningococcal sepsis.

Bloodstream infections in critically ill patients: an expert statement.

Bloodstream infection (BSI) is defined by positive blood cultures in a patient with systemic signs of infection and may be either secondary to a documented source or primary-that is, without identified origin. Community-acquired BSIs in immunocompetent adults usually involve drug-susceptible bacteria, while healthcare-associated BSIs are frequently due to multidrug-resistant (MDR) strains. Early adequate antimicrobial therapy is a key to improve patient outcomes, especially in those with criteria for sepsis or septic shock, and should be based on guidelines and direct examination of available samples. Local epidemiology, suspected source, immune status, previous antimicrobial exposure, and documented colonization with MDR bacteria must be considered for the choice of first-line antimicrobials in healthcare-associated and hospital-acquired BSIs. Early genotypic or phenotypic tests are now available for bacterial identification and early detection of resistance mechanisms and may help, though their clinical impact warrants further investigations. Initial antimicrobial dosing should take into account the pharmacokinetic alterations commonly observed in ICU patients, with a loading dose in case of sepsis or septic shock. Initial antimicrobial combination attempting to increase the antimicrobial spectrum should be discussed when MDR bacteria are suspected and/or in the most severely ill patients. Source identification and control should be performed as soon as the hemodynamic status is stabilized. De-escalation from a broad-spectrum to a narrow-spectrum antimicrobial may reduce antibiotic selection pressure without negative impact on mortality. The duration of therapy is usually 5-8 days though longer durations may be discussed depending on the underlying illness and the source of infection. This narrative review covers the epidemiology, diagnostic workflow and therapeutic aspects of BSI in ICU patients and proposed up-to-date expert statements.

Time to appropriate antibiotic therapy is a predictor of outcome in patients with bloodstream infection caused by KPC-producing Klebsiella pneumoniae.

BACKGROUND: Bloodstream infections (BSIs) by Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (Kp) are associated with high mortality. The aim of this study is to assess the relationship between time to administration of appropriate antibiotic therapy and the outcome of patients with BSI due to KPC-Kp hospitalized in intensive care unit (ICU). METHODS: An observational study was conducted in the ICUs of two academic centers in Italy. Patients with KPC-Kp bacteremia hospitalized between January 2015 to December 2018 were included. The primary outcome was the relationship between time from blood cultures (BC) collection to appropriate antibiotic therapy and 30-day mortality. The secondary outcome was to evaluate the association of different treatment regimens with 30-day mortality and a composite endpoint (30-day mortality or nephrotoxicity). A Cox regression analysis to identify factors independently associated with 30-day mortality was performed. Hazard ratio (HR) and 95% confidence interval (CI) were calculated. RESULTS: A total of 102 patients with KPC-Kp BSI were included. The most common sources of infection were intra-abdominal (23.5%), urinary tract (20.6%), and skin and skin structure (17.6%). The 30-day mortality was 45%. Median time to appropriate antibiotic therapy was shorter in patients who survived (8.5 h [IQR 1-36]) versus those who died (48 h [IQR 5-108], p = 0.014). A propensity score matching showed that receipt of an in vitro active therapy within 24 h from BC collection was associated with lower 30-day mortality (HR = 0.36, 95% CI: 0.188-0.690, p = 0.0021). At Cox regression analysis, factors associated with 30-day mortality were primary bacteremia (HR 2.662 [95% CI 1.118-6.336], p = 0.027), cardiovascular disease (HR 2.196 [95% CI 1.082-4.457], p = 0.029), time (24-h increments) from BC collection to appropriate therapy (HR 1.382 [95% CI 1.132-1.687], p = 0.001), SOFA score (HR 1.122 [95% CI 1.036-1.216], p = 0.005), and age (HR 1.030 [95% CI 1.006-1.054], p = 0.012). Ceftazidime-avibactam-containing regimens were associated with reduced risk of composite endpoint (30-day mortality OR nephrotoxicity) (HR 0.231 [95% CI 0.071-0.745], p = 0.014) compared to colistin-containing regimens. CONCLUSIONS: Time to appropriate antibiotic therapy is an independent predictor of 30-day mortality in patients with KPC-Kp BSI. Appropriate antibiotic therapy should begin within 24 h from the collection of BC.

Nocardia bacteremia: A single-center retrospective review and a systematic review of the literature.

OBJECTIVES: Nocardia bacteremia is a rare but severe disease associated with high mortality. This systematic review is the largest and most comprehensive review performed over the past 20 years. METHODS: A single-center retrospective review of Nocardia bacteremia was performed using hospital microbiology records from January 1, 2010 to December 31, 2017. A systematic literature review was also performed to identify cases of Nocardia bacteremia described in the NCBI PubMed database in English between January 1, 1999 and December 31, 2018. RESULTS: Four new cases of Nocardia bacteremia are described. The systematic review identified 134 cases with sufficient information available for analysis. Of the total 138 cases, the median age was 58 years (interquartile range (IQR) 44-69 years) and 70% were male. Eighty-one percent were immunocompromised (corticosteroid use (49%), hematological malignancy (20%), solid organ transplant (20%), solid organ malignancy (19%), and hematopoietic stem cell transplantation (15%)) and 29% had endovascular devices. Pulmonary infection was the most common concurrent site of clinical disease (67%). The median incubation time to the detection of Nocardia bacteremia was 4 days (IQR 3-6 days). Blood cultures were the only positive microbiological specimen in 38% of cases. The median total duration of treatment was 75 days (IQR 25-182 days). Thirty-day all-cause mortality was 28% and overall all-cause mortality was 40%. CONCLUSIONS: Nocardia bacteremia is most frequently identified in immunocompromised patients and those with intravascular devices. Although rare, it represents a serious infection with high associated overall mortality.

A neonatal sequential organ failure assessment score predicts mortality to late-onset sepsis in preterm very low birth weight infants.

BACKGROUND: An operational definition of organ dysfunction applicable to neonates that predicts mortality in the setting of infection is lacking. We determined the utility of an objective, electronic health record (EHR)-automated, neonatal sequential organ failure assessment (nSOFA) score to predict mortality from late-onset sepsis (LOS) in premature, very low birth weight (VLBW) infants. METHODS: Retrospective, single-center study of bacteremic preterm VLBW newborns admitted between 2012 and 2016. nSOFA scores were derived for patients with LOS at multiple time points surrounding the sepsis evaluation. RESULTS: nSOFA scores at evaluation and at all points measured after evaluation were different between survivors and non-survivors. Among patients with an nSOFA score of >4, mortality was higher at evaluation (13% vs 67%, p < 0.001), +6 h (15% vs 64%, p = 0.002), and +12 h (7% vs 71%, p < 0.001) as compared to patients with a score of ≤4. Receiver operating characteristics area under the curve was 0.77 at evaluation (95% CI 0.62-0.92; p = 0.001), 0.78 at +6 h (0.66-0.92; p < 0.001), and 0.93 at +12 h (0.86-0.997; p < 0.001). CONCLUSIONS: The nSOFA scoring system predicted mortality in VLBW infants with LOS and this automated system was integrated into our EHR. Prediction of LOS mortality is a critical step toward improvements in neonatal sepsis outcomes.

Comparisons of clinical features and outcomes between Elizabethkingia meningoseptica and other glucose non-fermenting Gram-negative bacilli bacteremia in adult ICU patients.

BACKGROUND: Clinical information of Elizabethkingia meningoseptica (EM) bacteremia in intensive care unit (ICU) patients is limited and the impact on outcomes uncertain. The aim of this study was to investigate the clinical features and impact of EM bacteremia compared to other glucose non-fermenting Gram-negative bacilli (GNF-GNB) bacteremia in ICU patients. METHODS: This retrospective cohort study enrolled 70 patients who developed GNF-GNB bacteremia after ICU admission, including 19 cases of EM bacteremia (19/70, 27.1%). The main outcome measure was in-hospital mortality. RESULTS: The patients with EM bacteremia had a lower rate of appropriate antibiotic therapy (15.8% vs. 62.7%, p < 0.001) and a longer time to appropriate antibiotic therapy (76.8 ± 46.4 vs. 35.1 ± 38.7 h, p < 0.001), but with a less severity in acute physiology and chronic health evaluation (APACHE) II score and shock status (p < 0.05) at the onset of bacteremia, compared to those with non-EM bacteremia. The in-hospital mortality between those with EM bacteremia and non-EM bacteremia was similar (63.2% vs. 51.0%, p = 0.363). However, primary bacteremia was more frequently noted in EM compared with non-EM group (57.9% vs. 25.5%, p = 0.011), and odds ratio 4.294 (95% confidence interval 1.292-14.277, p = 0.017) in multivariate regression analysis. CONCLUSION: Among the patients with GNF-GNB bacteremia, the numbers of the cases with primary bacteremia and inappropriate therapy were significantly more in EM group than those in non-EM group.

Cell-Free Hemoglobin Is Associated With Increased Vascular Resistance and Reduced Peripheral Perfusion in Severe Malaria.

BACKGROUND: In severe falciparum malaria, unlike sepsis, hypotension on admission is uncommon. We hypothesized that low nitric oxide bioavailability due to the presence of cell-free hemoglobin (CFH) increases vascular tone in severe malaria. METHODS: Patients with severe malaria (n = 119), uncomplicated malaria (n = 91), or suspected bacterial sepsis (n = 56), as well as healthy participants (n = 50), were recruited. The systemic vascular resistance index (SVRI) was estimated from the echocardiographic cardiac index and the mean arterial pressure. RESULTS: SVRI and hematocrit levels were lower and plasma CFH and asymmetric dimethylarginine levels were higher in patients with malaria, compared with healthy participants. In multivariate linear regression models for mean arterial pressure or SVRI in patients with severe malaria, hematocrit and CFH but not asymmetric dimethylarginine were significant predictors. The SVRI was lower in patients with suspected bacterial sepsis than in those with severe malaria, after adjustment for hematocrit and age. Plasma CFH levels correlated positively with the core-peripheral temperature gradient and plasma lactate levels and inversely with the perfusion index. Impaired peripheral perfusion, as reflected by a low perfusion index or a high core-peripheral temperature gradient, predicted mortality in patients with severe malaria. CONCLUSIONS: CFH is associated with mean arterial pressure, SVRI, and peripheral perfusion in patients with severe malaria. This may be mediated through the nitric oxide scavenging potency of CFH, increasing basal vascular tone and impairing tissue perfusion.

Risk factors for bacteremia in children with febrile neutropenia

Background/aim: Bacteremia remains an important cause of morbidity and mortality during febrile neutropenia (FN) episodes. We aimed to define the risk factors for bacteremia in febrile neutropenic children with hemato-oncological malignancies. Materials and methods: The records of 150 patients aged ≤18 years who developed FN in hematology and oncology clinics were retrospectively evaluated. Patients with bacteremia were compared to patients with negative blood cultures. Results: The mean age of the patients was 7.5 ± 4.8 years. Leukemia was more prevalent than solid tumors (61.3% vs. 38.7%). Bacteremia was present in 23.3% of the patients. Coagulase-negative staphylococci were the most frequently isolated microorganism. Leukopenia, severe neutropenia, positive peripheral blood and central line cultures during the previous 3 months, presence of a central line, previous FN episode(s), hypotension, tachycardia, and tachypnea were found to be risk factors for bacteremia. Positive central line cultures during the previous 3 months and presence of previous FN episode(s) were shown to increase bacteremia risk by 2.4-fold and 2.5-fold, respectively. Conclusion: Presence of a bacterial growth in central line cultures during the previous 3 months and presence of any previous FN episode(s) were shown to increase bacteremia risk by 2.4-fold and 2.5-fold, respectively. These factors can predict bacteremia in children with FN.

Clinical characteristics and outcomes of community and hospital-acquired Acinetobacter baumannii bacteremia.

PURPOSE: We aimed to characterize clinical manifestations of the patients with bacteremia due to community-acquired Acinetobacter baumannii and evaluate the outcomes of these patients. METHODS: We conducted a retrospective study to include adult patients with A. baumannii bacteremia and then classified them into two groups: community-acquired A. baumannii bacteremia and hospital-acquired A. baumannii bacteremia. Characteristics and outcomes between 2 groups were compared. The Galleria mellonella infection survival model was used to determine the virulence of A. baumannii in these 2 groups. RESULTS: There were 63 patients with A. baumannii bacteremia: 21 patients with community-acquired (CA) bacteremia and 42 patients with hospital-acquired (HA) bacteremia. Three patients with CA bacteremia were excluded due to healthcare-associated risks of infection. The remaining 18 patients with CA bacteremia had carbapenem-susceptible A. baumannii (CA-CSAB). Among the 42 patients with HA bacteremia, 11 patients had carbapenem-susceptible A. baumannii (HA-CSAB) and 31 patients had carbapenem-resistant A. baumannii (HA-CRAB). The 30-day mortality rates of those with CA-CSAB did not differ from those with HA-CSAB bacteremia but were significantly lower than those with HA-CRAB (p = 0.003). The factors influencing 30-day mortality were infection with CRAB (p = 0.004), appropriate empirical antimicrobial therapy (p = 0.002), and higher Acute Physiology and Chronic Health Evaluation II score (p < 0.001). The G. mellonella assay showed no differences in survival rates among CA-CSAB, HA-CSAB, and HA-CRAB. CONCLUSIONS: Patients with bacteremia due to CA-CSAB and HA-CSAB had similar outcomes. Similar virulences of CA-CSAB and HA-CSAB were confirmed with the G. mellonella infection model.