Episodes Of Bacteremia Research Articles

Australian Group on Antimicrobial Resistance (AGAR) Australian Enterococcal Surveillance Outcome Program (AESOP) Bloodstream Infection Annual Report 2023.

From 1 January to 31 December 2023, fifty-six institutions across Australia participated in the Australian Enterococcal Surveillance Outcome Program (AESOP). The aim of AESOP 2023 was to determine the proportion of enterococcal bacteraemia isolates in Australia that were antimicrobial resistant, and to determine the Enterococcus faecium molecular epidemiology. Of the 1,599 unique episodes of enterococcal bacteraemia investigated, 92.9% were caused by either E. faecalis (51.8%) or E. faecium (41.1%). Ampicillin and vancomycin resistance were not detected in E. faecalis but were detected in 94.2% and 50.8% of E. faecium respectively. Two linezolid-resistant E. faecalis were identified in 2023. Both isolates had linezolid minimum inhibitory concentrations (MICs) of 6.0 mg/L, were vancomycin susceptible, and harboured the optrA gene. Overall, 53.2% of E. faecium harboured either the vanA or the vanB gene; of these, 27.3% harboured vanA, 72.1% harboured vanB, and 0.6% harboured vanA and vanB. The percentage of vancomycin-resistant E. faecium bacteraemia isolates in Australia remains substantially higher than that recorded in most European countries. The E. faecium isolates consisted of 58 multi-locus sequence types (STs); 85.7% of isolates were classified into seven major STs, each containing ten or more isolates. All major STs belonged to clonal complex (CC) 17, a global hospital-adapted polyclonal E. faecium CC. The major STs (ST78, ST1424, ST17, ST80, ST796, ST1421 and ST555) were found across most regions of Australia, with ST78 identified in all regions. Overall, 58.3% of isolates belonging to the seven major STs harboured the vanA or vanB gene. AESOP 2023 has shown that enterococcal bacteraemia episodes in Australia continues to be frequently caused by polyclonal ampicillin-resistant high-level gentamicin-resistant vanA- or vanB-positive E. faecium which have limited treatment options.

Serotype distribution and clinical characteristics of Group B Streptococcus Bacteremia in nonpregnant adults: a 15-Year Multicenter Study in Korea

BackgroundGroup B Streptococcus (GBS) bacteremia in nonpregnant adults is of increasing concern, particularly among the elderly in underlying conditions. This study analyzed the serotype distribution, antimicrobial resistance patterns, and clinical characteristics of GBS bacteremia in nonpregnant adults over a 15-year period in two tertiary hospitals in Korea.MethodsFrom 2007 to 2021, patients aged ≥ 19 years with GBS bacteremia were identified via retrospective electronic medical record review. GBS isolates were collected through a hospital-wide surveillance system and confirmed via MALDI-TOF-MS. Multilocus sequence typing (MLST) was conducted for serotype VIII and undetermined serotype isolates. Clinical and laboratory data were analyzed to assess trends and mortality risk factors.ResultsA total of 264 episodes of GBS bacteremia were identified, with 147 isolates successfully re-cultured and 125 isolates and patients included in the clinical characteristic analysis. Serotype VIII emerged as the most common serotype (42.1% in 2019–2021) with a significant increase in prevalence over time (P = 0.02). MLST of serotype VIII revealed ST2 as the dominant sequence type (87.8%). Antimicrobial resistance rates for erythromycin, clindamycin, and levofloxacin were 27.2%, 30.4%, and 23.2%, respectively, with notable variability among serotypes. The 30-day mortality rate was 12.8%. Male sex (aOR: 2.18; 95% CI: 1.15–4.13, P = 0.02) and SOFA score (aOR per unit increase: 1.25; 95% CI: 1.12–1.38, P < 0.001) were significantly associated with mortality.ConclusionsThis study highlights the emergence of serotype VIII as a predominant cause of GBS bacteremia and its association with ST2 in South Korea. Male sex and higher SOFA scores were independent risk factors for mortality. The findings emphasize the need for ongoing surveillance and consideration of serotype-specific strategies in clinical management and vaccine development.

Duration of antimicrobial treatment for uncomplicated streptococcal bacteraemia: another example of shorter is better

ObjectivesDuration of treatment for uncomplicated streptococcal bacteraemia is unknown. The study aims to assess clinical outcomes of patients with uncomplicated streptococcal bacteraemia receiving a short course (5-10 days) of antimicrobial treatment compared to those receiving the traditional, longer duration (11-18 days). MethodsThis retrospective study was conducted at the Lausanne University Hospital, Switzerland and included episodes of uncomplicated streptococcal bacteraemia among adult patients from 2015 to 2023. Clinical failure was defined as mortality, recurrence of bacteraemia by the same streptococcal species and development in bone and joint infection within 120 days. ResultsDuring the study period, 336 episodes of uncomplicated streptococcal bacteraemia were included. The median duration of antimicrobial treatment was 10 days (interquartile range: 7-14); 184 (55%) and 152 (45%) episodes received a short (5-10 days) and long (11-18 days) duration of antimicrobial treatment, respectively. Forty-three (13%) episodes had clinical failure; 120-day mortality was 11% (36 episodes); recurrence of bacteraemia by the same streptococcal species was observed in 8 episodes (2%). No difference in clinical failure was observed between episodes receiving short and long courses of antimicrobial treatment (10% versus 16%; P 0.143). The Cox multivariable regression model found that a Charlson comorbidity index >4 (aHR 4.87, 95% CI 3.08-7.71), and septic shock (1.67, 1.04-2.67) were associated with clinical failure; a short course of antimicrobial treatment was not associated with clinical failure (0.90, 0.57-1.12). ConclusionsThis study has shown that a short duration of antimicrobial treatment for cases of streptococcal bacteraemia is effective and safe.

Bacteriemias por anaerobios estrictos

Introduction. Anaerobic bacteremia represents 0.5-12% of all bacteremias and its mortality is high, ranging from 25-44%. The aim was to know our data to compare them with existing data and demonstrate the importance of actively searching for these microorganisms in blood culture samples. Material and methods. A retrospective descriptive study in which the medical records of patients with significant episodes of anaerobic bacteremia were reviewed over a period of 8 years (2014-2022). Results. A total of 59,898 blood cultures were processed, of which 10,451 were positive (17%). An anaerobic microorganism was identified in 209 patients. Anaerobic bacteremia accounted for 2.11% of the total number of positive blood cultures. The mean age was 63.55 years (17-96), 66% of whom were men. The origin was community in 63.64%, of nosocomial origin in 15.31% and associated with health care in 17.70%. The focus of infection was the abdominal (39.23%), followed by the respiratory (13.88%) and skin and soft tissues (13.39%). The most frequent comorbidities were: arterial hypertension (49.76%), dyslipidemia (29.67%), neoplasia (26.32%) and diabetes (26.32%). The main species isolated were the group Bacteroides spp. (44.50%) (n=93) highlighting Bacteroides group fragilis (n=65), followed by Clostridium spp. (20%) (n=42) highlighting Clostridium perfringens (n=30). The clinical evolution was good in 67.46%. The mean length of stay was 27.8 days and was associated with 20% mortality. Conclusions. Bacteremias due to anaerobes represented 2.11% of the total number of true bacteremias, so we consider the active search for these microorganisms to be appropriate.

Epidemiology of Bacteremia in Patients with Hematological Malignancies and Hematopoietic Stem Cell Transplantation and the Impact of Antibiotic Resistance on Mortality: Data from a Multicenter Study in Argentina.

The epidemiology of bacteremia and the antibiotic resistance profile (ARP) of Gram-negative bacilli (GNB) in hematological malignancies (HM) and hematopoietic stem cell transplant (HSCT) patients may differ according to geographic region. In addition, multidrug-resistant organisms (MDROs) may impact mortality. This is a prospective, observational, and multicenter study. The first episodes of bacteremia in adult patients with HM or HSCT were included. The risk factors for 30-day mortality were identified. One thousand two hundred and seventy-seven episodes were included (HM: 920; HSCT: 357). GNB were isolated in 60.3% of episodes, with Enterobacterales (46.9%) and P. aeruginosa (8.5%) being the most frequent. Gram-positive cocci were isolated in 41.9% of episodes, with coagulase-negative staphylococci (19.8%) and S. aureus (10.4%) being the most frequent. MDROs were isolated in 40.2% (24.4% GNB). The ARP of GNB in patients with HM vs. HSCT was cefepime: 36.8% vs. 45.7% (p = 0.026); piperacillin-tazobactam: 31.05% vs. 45.2% (p < 0.0001); carbapenems: 18.9% vs. 27.3% (p = 0.012); and aminoglycosides: 9.3% vs. 15.4% (p = 0.017), respectively. Overall mortality between patients with HM and HSCT was 17.5% vs. 17.6% (p = 0.951), respectively. The risk factors for mortality were relapsed and refractory underlying disease, corticosteroids use, respiratory source, septic shock, and GNB resistant to meropenem, while 7-day clinical response was a protective factor for survival. Bacteremia was frequently caused by GNB, with a large proportion of MDROs and a high level of antibiotic resistance, especially in patients with HSCT. Carbapenem-resistant GNB bacteremia was associated with a significant increase in mortality.

Time to positivity of blood cultures in paediatric patients.

Continuous monitoring of blood culture (BC) systems allows rapid detection of microbial growth. We aimed to determine differences in time to positivity (TTP) in BACTEC BC between organisms and whether a 36-h period was sufficient to detect all relevant pathogenic bacteria for children admitted to a tertiary care paediatric hospital. This was a retrospective audit of positive aerobic (AE) and anaerobic (AN) BC from paediatric inpatients with available TTP from 1 August 2016 to 2 January 2019. First positive BC per bacteraemia episode was analysed. Overall, 649 BC were positive, of which 480 first positive BC were analysed: 246 AE (51.3%) only, 216 paired (45%) (108 AE and 108 AN) and 18 AN (3.8%) only. There were 372 episodes of bacteraemia in 340 patients. Median age was 19 months (interquartile range (IQR): 1.25-60). Median TTP for AE and AN cultures was 13.20 (IQR: 9.84-18.48) and 13.92 h (IQR: 10.32-17.04), respectively. Organisms were GNR 49.7%, GPC 29.6%, contaminants 14.5%, mixed 3.0%, other 2.4% and yeast 0.8%. Streptococcus agalactiae had the fastest median TTP in AE and AN cultures, followed by Escherichia coli (AE 8.88 vs. 10.20 h). For paired AE and AN cultures, TTP was faster for AE versus AN cultures (13.36 vs. 14.52 h, P = 0.001). A 36-h cut-off time captured 97.7% AE BC and 99.1% AN BC with pathogens, and 86.5% AE BC and 91.7% AN BC with contaminants, respectively. GNR were the commonest pathogens in paediatric BC and faster growth was detected in AE versus AN cultures. By 36 h, >97.7% of BC were positive for pathogens versus 86.5% for contaminants.

Burns, Sepsis and Procalcitonin

The basis of the pathogenesis of burn disease is a systemic inflammatory response syndrome with episodes of bacteremia and the development of sepsis. An analysis of the literature showed that the existing clinical diagnostic scales for sepsis do not allow a confident diagnosis. The interest in changes in the concentration of procalcitonin in the blood serum is justified by the fact that this prohormone is one of the proinflammatory mediators, the concentration of which quickly increases during local and systemic bacterial and fungal infections. It seems important to consider the possibilities of various scales for determining the criteria for sepsis, analyze the values of procalcitonin and its monitoring for more effective diagnosis and procalcitonin-controlled antibiotic therapy in patients with burns.CONCLUSION. The problem of clinical diagnosis of sepsis in patients with burns has not yet been solved. Procalcitonin is an effective biomarker of bacterial infection, and its monitoring reflects the dynamics of the burn disease, predicts the outcome, indicates the effectiveness of antibiotic therapy and allows for its correction.

Clinical Characteristics, Management, and Outcomes of Bacteremia in Children with Cancer: A Retrospective Study

Abstract Background Bacteremia is a common infectious complication among pediatric oncology patients, yet management practices are not standardized. Antibiotic treatment courses as short as seven days are supported by literature and could improve patient quality of life and resource use. However, it is not known if short courses are associated with greater treatment failure in immunocompromised patients. Methods We conducted a retrospective study at St. Jude Children’s Research Hospital, including patients with a laboratory confirmed bloodstream bacterial infection between April 1, 2022, and March 31, 2023. Clinical characteristics such as age, gender, type of malignancy, phase of treatment, underlying chronic conditions, and clinical sites of infection were collected. Antibiotics used, duration of therapy, and route of administration were also gathered to examine clinical management. Clinical outcomes were measured by documenting ICU admission, oxygen, fluid and vasopressor requirements, date of hospital discharge, bacteremia recurrence, and mortality. Results 86 patients contributed 112 bacteremia episodes that met eligibility criteria. Severe neutropenia was present at onset in 68% of all episodes and 32% of patients did not have neutrophil recovery over 500 cells/ml during the episode. Gram-negative organisms accounted for 52% of isolated organisms, with the most common organisms isolated overall being Escherichia coli (19%), followed by Klebsiella pneumoniae (14%), and Viridans group streptococcus (14%). The median length of antibiotic treatment was 12 days. Treatment duration was not associated with oncologic diagnosis or Gram-negative versus Gram-positive infection. Conclusion Bacteremia occurs more frequently in patients who are neutropenic, especially those who are severely neutropenic with an absolute neutrophil count less than 500 cells/mL. Treatment duration is not associated with primary cancer diagnosis or type of bacteremia. In this single high resource setting, bloodstream infections resulted in significant morbidity, resource use, and a mortality rate of 8%, highlighting opportunities for investigation to improve clinical practices.

Epidemiology of childhood invasive pneumococcal disease in Australia: a prospective cohort study

BackgroundThe widespread use of pneumococcal conjugate vaccines (PCV) has changed the epidemiology of invasive pneumococcal disease (IPD) in children globally.MethodsMulticentre prospective audit of IPD episodes from five paediatric hospitals in...

Pre‐engraftment bacteremia after allogeneic hematopoietic cell transplantation without primary fluoroquinolone antibacterial prophylaxis

AbstractBackgroundBacteremia is a common complication in allogeneic hematopoietic cell transplant recipients (alloHCTr), especially during the pre‐engraftment period. International guidelines recommend antibacterial prophylaxis (ABP), despite potential selection for multidrug‐resistant organisms (MDRO). Limited contemporary data exist on the epidemiology of pre‐engraftment bacteremia in alloHCTr, who do not receive ABP.MethodsWe performed a retrospective observational single‐center cohort study including all consecutive adult alloHCTr (2015–2021), investigating the incidence, risk factors, and outcomes of bacteremia during the engraftment period. Primary fluoroquinolone (FQ) ABP is not routinely administered in our center.ResultsAmong 421 patients identified, 124 bacteremia episodes were observed in 121/421 (29%) alloHCTr. The median time to the 1st bacteremia episode was 9 days (IQR 6–11). Most (105/124, 85%) episodes were monomicrobial, while &gt;1 pathogens were identified in 19/124 (15%) episodes. Overall, 152 pathogens were isolated, with a predominance of Gram‐positive (118/152, 78%), including coagulase‐negative staphylococci (n:47), streptococci (n:46), and enterococci (n:15), followed by Gram‐negative bacteria (GNB, 30/152, 20%), and anaerobes (4/152, 3%). There were 2/152 (1%) MDRO (extended‐spectrum beta‐lactamase producing) GNB. Multivariable analyses identified age &gt;40‐year‐old (OR 2.4, P = 0.02), male gender (OR 1.8, P = 0.02), and a haploidentical/mismatched unrelated donor (OR 2.5, P &lt; 0.001) as independent risk factors for bacteremia. All cause 30‐day mortality among alloHCTr with bacteremia was 0.8% (1/121): one patient died due to an HCT‐related complication.ConclusionDespite lack of primary FQ ABP, low rates of bacteremia were observed during the pre‐engraftment period, with low MDRO prevalence and mortality. Our findings may allow to revisit the need for primary universal FQ ABP in high‐risk neutropenic hematology patients. image

Using machine learning to predict bacteremia in urgent care patients on the basis of triage data and laboratory results

BackgroundDespite advancements in antimicrobial therapies, bacteremia remains a life-threatening condition. Appropriate antimicrobials must be promptly administered to ensure patient survival. However, diagnosing bacteremia based on blood cultures is time-consuming and not something emergency department (ED) personnel are routinely trained to do. MethodsThis retrospective cohort study developed several machine learning (ML) models to predict bacteremia in adults initially presenting with fever or hypothermia, comprising logistic regression, random forest, extreme gradient boosting, support vector machine, k-nearest neighbor, multilayer perceptron, and ensemble models. Random oversampling and synthetic minority oversampling techniques were adopted to balance the dataset. The variables included demographic characteristics, comorbidities, immunocompromised status, clinical characteristics, subjective symptoms reported during ED triage, and laboratory data. The study outcome was an episode of bacteremia. ResultsOf the 5063 patients with initial fever or hypothermia from whom blood cultures were obtained, 128 (2.5 %) were diagnosed with bacteremia. We combined 36 selected variables and 10 symptoms subjectively reported by patients into features for analysis in our models. The ensemble model outperformed other models, with an area under the receiver operating characteristic curve (AUROC) of 0.930 and an F1-score of 0.735. The AUROC of all models was higher than 0.80. ConclusionThe ML models developed effectively predicted bacteremia among febrile or hypothermic patients in the ED, with all models demonstrating high AUROC values and rapid processing times. The findings suggest that ED clinicians can effectively utilize ML techniques to develop predictive models for addressing clinical challenges.

Early bacteremia following allogeneic hematopoietic stem cell transplantation without antibiotic prophylaxis: epidemiology and antimicrobial resistance

ObjectiveBacteremia is a serious complication in patients undergoing allogeneic hematopoietic stem cell transplantation. The aim of this study was to determine the frequency, epidemiological profile, and risk factors of bacteremia early after allogeneic hematopoietic stem cell transplantation. MethodsAn observational descriptive retrospective study was conducted in patients who received transplants between January 2016 and December 2021. Early bacteremia was defined as blood stream infection occurring between Day 0 and Day 100 after transplantation. ResultsForty episodes of early bacteremia occurred in 36/245 transplanted patients. Fifteen episodes (37.5%) were due to gram-positive bacteria and 25 (62.5%) to gram-negative bacteria. The most frequent species isolated were coagulase negative staphylococci (CoNS) in gram-positive bacteremia (n = 8/15), and Klebsiella species (8/25) and Pseudomonas species (8/25) in gram-negative bacteremia. Twenty-nine episodes of bacteremia (72.5%) occurred during the first 30 days after transplantation with a median time of nine days (range: 0-90 days). Coagulase negative staphylococci were methicillin-resistant in 75% of cases, the only Staphylococcus aureus isolated was methicillin-resistant. All gram-positive bacilli were penicillin-resistant. Gram-negative bacilli were multidrug resistant in 61.5% of cases. In multivariate analysis, bone marrow as source of graft (p-value = 0.02) and cytomegalovirus reactivation (p-value = 0.02) were significantly associated with an increased risk of bacteremia. Mortality attributable to bacteremia was 2.8%. The one-year overall survival was not significantly different between those with and without bacteremia. ConclusionsBacteremia was more frequent within the first 30 days after transplantation indicating the crucial role of neutropenia. An increase in multidrug resistant gram-negative bacteremia was noted.

Clinical and microbiological characteristics of anaerobic bacteremia during 1994–2019: A Danish population-based cohort study

ObjectivesBacteremia with anaerobic bacteria is generally a marker of severe prognosis. However, population-based data is lacking. Our aim was to describe the epidemiology and the 30-day mortality rate of anaerobic bacteremia in a Danish population-based setting. MethodsIn this population-based cohort study, all first-time episodes of anaerobic bacteremia from the North Denmark Bacteremia Research Database during 1994–2019 were identified. Information on comorbidities, discharge diagnoses, and mortality was retrieved. 30-day mortality rates were calculated and a multivariate logistic regression analysis to identify risk factors for death was performed. Results1750 episodes with anaerobic bacteremia were identified, corresponding to an incidence rate of 12.5 per 100,000 inhabitants (increasing from 11.2 in 1994–2014 to 17.7 in 2015–2019). Of these episodes, a third were polymicrobial, and the majority (70 %) of patients had one or more comorbid conditions. Abdominal infection was the source of bacteremia in 61 % of patients, while it was unknown for 15 %. The most frequently isolated genera were Bacteroides (45 %), Clostridium (20 %) and Fusobacterium (6 %). The overall crude 30-day mortality rate was 27 %, but rates were even higher for patients of high age, with liver disease, and solid tumors. The odds ratio (OR) for 30-day mortality was 1.32 for Clostridium species, and 1.27 for polymicrobial bacteremia with aerobic bacteria. ConclusionsThe incidence rate of anaerobic bacteremia increased, and the 30-day mortality rate remained high during the study period. Multiple factors influence 30-day mortality rates, including high age, liver disease, solid tumor, polymicrobial bacteremia, and bacteremia with Clostridium species.

Fluoroquinolone Prophylaxis in Children With Cancer: A Pro/Con Discussion.

There are conflicting recommendations on whether to use or not to use fluoroquinolone prophylaxis in pediatric oncology patients. An international pediatric clinical practice guideline (CPG) recommends administering levofloxacin prophylaxis in patients with acute myeloblastic leukemia and relapsed acute lymphoblastic leukemia receiving intensive chemotherapy as this practice has been found to reduce episodes of fever and bacteremia. A separate European CPG does not recommend levofloxacin prophylaxis because of concerns for adverse effects, including potentiation of fluoroquinolone resistance and possible increased resistance to other classes of antibiotics. The nuance of the decision to give or not give prophylaxis is discussed in the context of published evidence defining the risks and benefits of levofloxacin prophylaxis for pediatric leukemia patients at high risk for bacterial infection. Knowledge gaps are also identified to guide further investigations to optimize the use of fluoroquinolone prophylaxis in pediatric patients receiving chemotherapy for cancer or undergoing a hematopoietic cell transplantation.

Whole Genome Sequencing for the Identification of a Streptococcus agalactiae Outbreak in Neonatal Intensive Care Unit

Background: While Streptococcus agalactiae (Group B Streptococcus [GBS]) infections in infants usually result from maternal transmission, healthcare-associated cases, particularly in the neonatal intensive care unit (NICU), can occur. Whole genome sequencing (WGS) can aid in investigating GBS outbreaks among infants in hospital settings. The aim of the study is to describe the investigation of GBS infections in NICU using WGS. Methods: Infection prevention and control (IPAC) at our hospital monitors the occurrence of late-onset GBS disease (LOD) in our 57-bed NICU, which consists of all private rooms. The occurrence of 2 cases of LOD within 2 weeks triggered an investigation, including WGS of the two isolates and isolates causing invasive GBS during the last 6 months in the unit. GBS isolates underwent WGS using Illumina at Canada’s National Microbiology Laboratory. All affected patients underwent chart-review. Outbreak description and investigation: In August 2023, two NICU neonates (patients 2,3) experienced LOD two weeks apart, one with bacteremic meningitis and the other with two bacteremic episodes three weeks apart. While WGS was pending two additional cases of late-onset GBS bacteremia (patients 4,5) occurred. Isolates from Pts 2,3 and 5 were indistinguishable from each other and from an isolate from an infant admitted to the NICU with early onset bacteremia on July 27, 2023 (day 1 of life) (patient 1). Weekly point prevalence for throat and rectal colonization over 3 weeks identified five infants colonized with unrelated strains. An additional long-stay infant (patient 6) developed GBS conjunctivitis due to a strain indistinguishable from (patient 4) by pulse field gel electrophoresis, WGS for the second cluster is pending. IPAC interventions: Lapses in IPAC practices were observed, with no commonalities among cases other than similar geographic location within the unit. We hypothesized transmission was due to horizontal transmission between babies due to these lapses. Basic IPAC measures, including hand hygiene and environmental cleaning, were reinforced; Additional Precautions were not used due to private rooms’ unit structure. No environmental samples were taken due to lack of an obvious environmental point or common source. Point prevalence monitoring persisted until no new cases related to the outbreak strains were further identified in three consecutive weekly point prevalence. Conclusions: Increased awareness of healthcare-associated transmission is crucial in NICU as LOD GBS emerges. WGS plays a key role in identifying transmission. Detecting a multi-strain outbreak can appropriately redirect investigations. Legend: Figure 1: Timeline of stay at NICU and infection timing for patients 1-6

Predictors and outcomes of multi-drug–resistant gram-negative bacteremia in patients with cancer: A retrospective cohort study at a tertiary cancer center in Oman

ObjectivesThis study aimed to delineate the characteristics and outcomes of gram-negative bacteremia (GNB) in oncology patients; analyze the risk factors for multi-drug–resistant (MDR) GNB; and assess its impact on the recurrence of bloodstream infection (BSI), hospital stay, and 30-day mortality. MethodsData, including demographics, clinical features, common cancers, and microbiologic findings, were collected retrospectively from electronic medical records of patients admitted with solid tumors and BSI episodes between January and December 2022. Fisher's exact tests were used to determine the effect of MDR-GNB on 30-day mortality and BSI recurrence. The Wilcoxon rank-sum test assessed the differences in the length of hospital stay. Logistic regression models identified the risk factors for MDR-GNB. ResultsAmong 1074 patients, 77 episodes of GNB bacteremia occurred in 59 individuals (47% male, median age 57.4 years). Of these, 37 (48%) were MDR-GNB. Carbapenem resistance was noted in 9.1% of GNB episodes. Previous antibiotic use was significantly associated with MDR-GNB (odds ratio 7.82; 95% confidence interval 2.52-24). MDR-GNB was linked to longer hospital stays (median 23 vs 10.5 days, P = 0.003) and higher recurrence rates than non-MDR-GNB (35.13% vs 5.0%, P <0.001). However, 30-day mortality did not significantly differ between the groups (35.14% vs 32.5%, P = 0.81). ConclusionPrevious antibiotic use predicted MDR-GNB in patients with solid tumor. MDR-GNB bacteremia increased the length of hospital stay and risk of recurrence compared with non-MDR-GNB bacteremia.

Enterococcal Bacteremia outbreaks during SARS-COV-2 in Intensive Care Unit (ICU): The role of Strain Identification

Background: An unprecedented burden of morbidity and mortality has been reported in patients admitted to healthcare facilities with SARS-COV-2 infection globally since March 2020. A higher incidence of ICU-acquired bloodstream infection has been described with the cumulative risk increased with the length of ICU stay, use of steroids, anti-inflammatory agents, and indwelling catheters. Additionally, SARS-COV-2 infection may increase the risk of bacteremia from gastrointestinal flora such as Enterococcus species by disrupting the gastrointestinal barrier and microbiome. Methods: We aimed to investigate the outbreaks of Enterococcus bacteremia in patients with SARS-COV-2 infection and included patients aged&gt;18 years admitted to the ICU at the Oklahoma City Veterans Affairs Medical Center who were infected with SARS-COV-2 and were identified as having positive blood cultures for Enterococcus faecalis, Enterococcus faecium including vancomycin-resistant species and other bacterial or candida species between March 1, 2020, to March 9, 2022. We collected the following data: duration of hospitalization including ICU stay, unit and room location during the hospital stay, blood culture collection date and results, duration, and site of central line placement, duration of ventilation, administration of antimicrobials and COVID-19 directed therapeutics using computerized patient record system (CPRS). We sent 10 E. faecalis and 12 E. Faecium isolates for genetic analysis. DNA was sequestered from each isolate and multi-locus sequence typing (MLST) was performed by amplifying 7 regions of the E. faecalis genome and 7 regions of the E. faecium genome by polymerase chain reaction (PCR). Resulting amplicons were sequenced and allele type for each gene region and overall sequence type was determined using MLST database (http://pubmlst.org). Results: There were 22 episodes of enterococcal bacteremia in a 3-month duration in the ICU in 20 patients of which 17 were associated with another episode with the same strain (Figure-1-2). Central line placement was noted in 18/22 episodes. Genetic analysis by multi-locus sequence typing of enterococcal bacterial strains was performed by the Public Health Reference Laboratory, Palo Alto. Similar strains were localized to patients in the same geographical region in the ICU (Figure 3). The isolates from 2 other patients who presented with the same strain of Enterococcus but were never hospitalized at the same time during the COVID-19 pandemic were localized to another hospital where both had received care at different times. Conclusion: Higher rates of enterococcal bacteremia were reported during the SARS-COV-2 pandemic. Geographical proximity with strained infection control measures accounted for ICU outbreaks seen in our tertiary care setup.

Examining the influence of Covid-19 restrictions, a nurse strike, and SARS-CoV-2 coinfection on bacteremia mortality: A Danish population-based cohort study (2019–2022)

ObjectivesBacteremia is an acute severe infection with high mortality. Changes in healthcare services and coinfections with SARS-CoV-2 may have affected the mortality for bacteremia during the COVID-19 pandemic, which has been reported for other major diseases. In this study we examine the all-cause bacteremia mortality amidst the COVID-19 pandemic. MethodsA population-based cohort study comprised of laboratory confirmed bacteremia episodes in the Capital Region, Denmark (March 2019–February 2022). Cox proportional hazards models were used to calculate hazard ratios (HR) and 95 % confidence intervals (CI) for all-cause bacteremia mortality associated with the Covid-19 restriction period, a strike period, and coinfection with SARS-CoV-2, adjusted for possible confounders. ResultsA total of 14,912 bacteremia episodes were identified in 12,693 patients during the study period. The 30- and 90-day all-cause mortality were 19 % and 27 %, respectively. The fully adjusted HR for 30- and 90-day all-cause mortality associated with the Covid-19 restriction period were 0.91 (95 % CI, 0.84 to 0.99) and 0.90 (95 % CI, 0.84 to 0.96), respectively, compared to the remaining time period. The corresponding HRs associated with SARS-CoV-2 coinfection were 1.29 (95 % CI, 1.11 to 1.50) and 1.36 (95 % CI, 1.20 to 1.55) compared to patients without coinfection. The association between the national nurse strike and all-cause bacteremia mortality was inconclusive. ConclusionsIn this large population-based cohort study, a significant reduction in all-cause mortality for bacteremia was observed during the Covid-19 restriction period in Denmark, while coinfection with SARS-CoV-2 seem to be a substantial risk factor for all-cause bacteremia mortality.

Genetic and Phenotypic Changes Related to the Development of mec-Independent Oxacillin Non-Susceptibility in ST8 Staphylococcus aureus Recovered after Antibiotic Therapy in a Patient with Bacteremia.

The mec-independent oxacillin non-susceptible S. aureus (MIONSA) strains represent a great clinical challenge, as they are not easily detected and can lead to treatment failure. However, the responsible molecular mechanisms are still very little understood. Here, we studied four clinical ST8-MSSA-t024 isolates recovered during the course of antibiotic treatment from a patient suffering successive episodes of bacteremia. The first isolates (SAMS1, SAMS2, and SAMS3) were susceptible to cefoxitin and oxacillin. The last one (SA2) was susceptible to cefoxitin, resistant to oxacillin, lacked mec genes, and had reduced susceptibility to teicoplanin. SA2 showed higher β-lactamase activity than SAMS1. However, β-lactamase hyperproduction could not be linked to oxacillin resistance as it was not inhibited by clavulanic acid, and no genetic changes that could account for its hyperproduction were found. Importantly, we hereby report the in vivo acquisition and coexistence of different adaptive mutations in genes associated with peptidoglycan synthesis (pbp2, rodA, stp1, yjbH, and yvqF/vraT), which is possibly related with the development of oxacillin resistance and reduced susceptibility to teicoplanin in SA2. Using three-dimensional models and PBP binding assays, we demonstrated the high contribution of the SA2 PBP2 Ala450Asp mutation to the observed oxacillin resistance phenotype. Our results should be considered as a warning for physicians and microbiologists in the region, as MIONSA detection and treatment represent an important clinical challenge.

Risk factors for bacteremic pneumonia and mortality (28-day mortality) in patients with Acinetobacter baumannii bacteremia

BackgroundPatients infected with Acinetobacter baumannii (AB) bacteremia in hospital have high morbidity and mortality. We analyzed the clinical characteristics of pneumonia and nonpneumonia-related AB bloodstream infections (AB BSIs) and explored the possible independent risk factors for the incidence and prognosis of pneumonia-related AB BSIs.MethodsA retrospective monocentric observational study was performed. All 117 episodes of hospital-acquired AB bacteremia sorted into groups of pneumonia-related AB BSIs (n = 45) and nonpneumonia-related AB BSIs (n = 72) were eligible. Univariate/multivariate logistic regression analysis was used to explore the independent risk factors. The primary outcome was the antibiotic susceptibility in vitro of pneumonia-related AB BSIs group. The secondary outcome was the independent risk factor for the pneumonia-related AB BSIs group.ResultsAmong 117 patients with AB BSIs, the pneumonia-related group had a greater risk of multidrug resistant A. baumannii (MDRAB) infection (84.44%) and carbapenem-resistant A. baumannii (CRAB) infection (80%). Polymyxin, minocycline and amikacin had relatively high susceptibility rates (> 80%) in the nonpneumonia-related group. However, in the pneumonia-related group, only polymyxin had a drug susceptibility rate of over 80%. Univariate analysis showed that survival time (day), CRAB, MDRAB, length of hospital stay prior to culture, length of ICU stay prior to culture, immunocompromised status, antibiotics used prior to culture (n > = 3 types), endotracheal tube, fiberoptic bronchoscopy, PITT, SOFA and invasive interventions (n > = 3 types) were associated with pneumonia-related AB bacteremia. The multivariate logistic regression analysis revealed that recent surgery (within 1 mo) [P = 0.043; 0.306 (0.098–0.962)] and invasive interventions (n > = 3 types) [P = 0.021; 0.072 (0.008–0.671)] were independent risk factors related to pneumonia-related AB bacteremia. Multivariate logistic regression analysis revealed that length of ICU stay prior to culture [P = 0.009; 0.959 (0.930–0.990)] and recent surgery (within 1 mo) [P = 0.004; 0.260 (0.105–0.646)] were independent risk factors for mortality in patients with pneumonia-related AB bacteremia. The Kaplan‒Meier curve and the timing test showed that patients with pneumonia-related AB bacteremia had shorter survival time compared to those with nonpneumonia-related AB bacteremia.ConclusionsOur study found that A. baumannii had a high rate of antibiotic resistance in vitro in the pneumonia-related bacteremia group, and was only sensitive to polymyxin. Recent surgery was a significantly independent predictor in patients with pneumonia-related AB bacteremia.