Cases Of Bacteremia Research Articles

Unveiling Ruminococcus gnavus Bacteremia: Clinical Characteristics and Implications.

Ruminococcus gnavus is a microbiota-forming, gram-positive coccus reportedly associated with several diseases, such as Crohn's disease. The number of in vitro studies on it is increasing. However, its clinical information is lacking in the literature, with only a few case reports published to date. To elucidate the significance of this organism, we describe its clinical characteristics in this study. During the study period (2013-2022), we identified 11 patients with R. gnavus bacteremia and conducted a retrospective chart review. Cases identified to be contaminated were excluded. We found 11 reports of R. gnavus bacteremia on PubMed and reviewed their clinical characteristics. Eleven R. gnavus bloodstream infection cases were identified in our facility. The median age of the patients was 83 years (interquartile range: 73.75-87.25). Seven cases had at least one documented intestinal lesion including three with malignancy cases, and two cases had uncompensated cirrhosis. In most cases, bacterial translocation was suspected as the entry mechanism. Among the 11 R. gnavus bloodstream infections, 7 (63.6%) were associated with intestinal lesions, and 2 (18.2%) had a history of suspected bacterial translocation without documented intestinal lesions. To the best of our knowledge, this is the largest cohort study on R. gnavus bloodstream infections. Intestinal entry was suspected in more than 80% of cases in both our cohort and the literature review cohort. For cases of bacteremia with an unknown etiology due to R. gnavus, a thorough examination of gastrointestinal lesions should be performed.

Rare Case of Fusobacterium necrophorum Bacteremia and Pleural Empyema Originating from a Burn Ulcer in a 16-Year-Old Female Patient

Rare Case of Fusobacterium necrophorum Bacteremia and Pleural Empyema Originating from a Burn Ulcer in a 16-Year-Old Female Patient

A Case of Bacteremia and Meningitis in a Neonate Infected with Group B Streptococcus via Breastfeeding Who Survived without Neurological Sequelae: A Case Report.

Invasive neonatal infection with Group B Streptococcus (GBS) is a disease of concern that can lead to neurological sequelae. Guidelines for preventing mother-to-child transmission have been introduced to reduce the incidence of early-onset infection, but guidelines for controlling the late-onset form are lacking. Recently, the trans-breastfeeding route of transmission has been highlighted as an example of late-onset infection, but no consensus on how to manage such infections has been reached. In this report, we describe a case of late-onset bacteremia/meningitis in a neonate suspected to have been infected with GBS via breastfeeding. A vaginal culture test of the mother at 35 weeks' gestation was negative for GBS. Since she had symptoms of mastitis, breast milk and nipple cultures were also tested and found to be positive for the strain of GBS identified in the neonate on genetic analysis. Diagnosis of trans-mammary GBS infection is challenging because breastfeeding-related events are difficult to identify. In our case, the diagnosis was based on the mother's history of mastitis, and the patient was treated without escalation to sequelae. When a neonate develops a fever, physicians should consider GBS infection and examine the mother's medical history to facilitate accurate diagnosis, especially if the history includes mastitis. A breast milk culture should be performed if the mother has mastitis, especially in cases of infection in preterm infants and in recurrent cases.

Lock, stock, and Leuconostoc: an unusual presentation of a rare pathogen

Leuconostoc mesenteroides is a Gram-positive bacterium in the Lactobacillaceae family. This species is rarely encountered clinically and in the past was regarded as a contaminant when cultured. Recently it is being recognized as a pathogen responsible for opportunistic infections in immunocompromised patients. Compared to other Gram-positive cocci, Leuconostoc spp. carry intrinsic resistance to vancomycin. It is not common for clinical microbiology laboratories to isolate this organism and instead incorrectly report enterococcus and streptococcus organisms. Here, we present a case of bacteremia resulting in febrile illness and pneumonia in an 81-year-old woman with a history of rheumatoid arthritis and a notable lapse between immunomodulator therapy exposure. She was successfully treated when this organism was identified, and her antibiotic therapy was switched from vancomycin to ampicillin-sulbactam. This case highlights the importance of considering L. mesenteroides as a source of infection in patients predisposed to an immunocompromised state despite this organism’s being a rare pathogen. Keywords: Leuconostoc mesenteroides, rheumatoid arthritis, immunomodulators; vancomycin resistance

MIC trends of vancomycin and teicoplanin among methicillin resistant CoNS isolates from new born blood cultures in a tertiary care centre in Southern India.

Coagulase-negative-Staphylococci (CoNS) are important etiological agent of bacteraemia in newborn babies. Methicillin resistant CoNS infections have only limited treatment options. The antimicrobial susceptibility pattern of Methicillin Resistant CoNS isolates from newborn blood cultures was studied with special reference to MICs of Vancomycin and Teicoplanin. The study population included Methicillin Resistant Coagulase Negative Staphylococcal isolates (MRCoNS) from newborn blood cultures, during a one-year period. Minimum inhibitory concentration (MIC) of Vancomycin and Teicoplanin in Methicillin resistant CoNS isolates was determined by macrobroth dilution method as per CLSI guidelines and by automated methods. Coagulase Negative Staphylococci were the etiological agent in 73.7% (n=56) cases of neonatal bacteremia. Methicillin resistance in newborn CoNS was found to be 58.9%. All the MRCoNS isolates had vancomycin and teicoplanin MICs in the susceptible range. There were MRCoNS isolates with MICs in the upper limit of susceptible range for both vancomycin and teicoplanin, which can result in poor clinical response. Continuous large scale multi-centre surveillance studies with special attention to study the MIC pattern of the high-end anti-MRSA agents like vancomycin, teicoplanin, linezolid are to be carried out. This will help the clinicians to judiciously prescribe the antibiotics, which is very essential for antimicrobial stewardship.

EFFECT of daily antiseptic bathing with octenidine on ICU-acquired bacteremia and ICU-acquired multidrug-resistant organisms: a multicenter, cluster-randomized, double-blind, placebo-controlled, cross-over study.

Antiseptic bathing has garnered attention in an effort to reduce hospital-acquired infections. Previous studies have shown the efficacy of antiseptic bathing in high-risk environments, such as intensive care units (ICUs), using chlorhexidine. In this study we aimed to evaluate the effectiveness of octenidine as a potential alternative due to its established popularity and widespread use in Europe. We compared the rates of ICU-acquired primary bacteremia and ICU-acquired multidrug-resistant organisms (MDROs) in a multicenter, cluster-randomized, double-blind, placebo-controlled, cross-over study using octenidine-impregnated and placebo washcloths. On 44 ICUs in 23 hospitals throughout Germany, we compared individual ICUs with themselves over two 12-month time periods. All data were obtained digitally via hospital information systems as individual ward-movement data and microbiological test results; both endpoints were algorithmically derived. 104,039 ICU episodes from 93,438 patients with 712,784 microbiological test results were analyzed, thereby detecting 1508 cases of ICU-acquired primary bacteremia and 1871 cases of ICU-acquired MDRO. Bathing with octenidine-impregnated washcloths prevented ICU-acquired primary bacteremia; a risk reduction of 17% was seen homogeneously across all participating ICUs (adjusted hazard ratio (HR) 0.83, 95% confidence interval (CI) [0.75; 0.92], p = 0.0003). This reduction affected predominantly coagulase-negative staphylococci (53%) and enterococci (17%). However, no intervention effect was seen for ICU-acquired MDROs (adjusted HR 0.98, 95% CI [0.83; 1.15]). Heterogeneity among intra-ICU intervention effects on MDRO acquisition was substantial. Antiseptic bathing with octenidine may be effective in preventing ICU-acquired primary bacteremia, particularly due to Gram-positive bacteria and common skin commensals.

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.

Trends in Enterococcus faecium Bacteremia: Exploring Risk Factors with Emphasis on Prior Antibiotic Exposure

Enterococcal bacteremia (EB) is on the rise both in Sweden and globally. While Enterococcus faecalis (E. faecalis) is susceptible to ampicillin and piperacillin/tazobactam (pip/taz), Enterococcus faecium (E. faecium) is not. Historically, most enterococcal infections have been caused by E. faecalis, but the epidemiology is changing with increasing recognition of enterococci as nosocomial pathogens and the emergence of resistance to commonly used antimicrobial agents. The use of pip/taz has increased dramatically in Sweden, but it is unknown if this has affected the relative incidence of E. faecalis/E. faecium bacteremia. Here, we investigate whether the number and proportion of E. faecium bacteremia (EfmB) cases have increased. Additionally, risk factors associated with EfmB with a focus on prior antibiotic exposure are analyzed. Medical journals of 360 patients with EB admitted to Sahlgrenska University Hospital are reviewed. The proportion of EfmB cases increased from 41% in 2015 to 51% in 2021. Hospital-acquired infection, previous exposure to pip/taz, and carbapenems are identified as independent risk factors for EfmB. There are considerable patient-related differences between the EfmB and EfsB groups, but there is no difference in mortality rates. In conclusion, the increasing proportion of EfmB cases is concerning and is seen parallel to the expanding use of pip/taz, one possible contributing factor. Our findings suggest that a cautious approach to antibiotic use is essential to prevent the spread of antibiotic-resistant bacteria.

Group B Streptococcus Infections in Non-Pregnant Adults, Italy, 2015-2019.

Group B Streptococcus (GBS, Streptococcus agalactiae) is a pathogen of increasing importance in adults. Severe and invasive cases in non-pregnant adults were collected during the period 2015-2019 by voluntary-based surveillance. In total, 108 GBS strains were phenotypically and genotypically characterized for the serotype, antimicrobial resistance, pili, surface protein genes, and the hyper-virulent adhesin hvgA. Patients were divided into two age groups: adults (18-64 years; n = 32) and older adults (≥65 years; n = 72). The average age was 70.8 years, with a male/female ratio of 1.7. Most isolates were recovered from cases of bacteremia (blood, n = 93), and a higher frequency of invasive GBS infections (iGBS) was found among older adults (66.7%). Serotype III was the most frequent (n = 41, 38%), followed by type Ia and type V (n = 20 each, 18.5%). Serotypes Ia, Ib, II, III, IV, and V accounted for all but one isolates (99.1%). The iGBS isolates were universally susceptible to penicillin, while the prevalence of resistance to clindamycin, erythromycin, tetracycline, and high-level gentamicin resistance was 26.8%, 24.1%, 85.2%, and 5.5%, respectively, with the predominance of the erm(B) gene for macrolide resistance and the tet(M) gene for tetracycline resistance. The associations between the serotypes/antimicrobial resistance/virulence traits underlined the increasing importance of serotype III and its contribution to antimicrobial resistance as well as the steady increase over time of serotype IV. This nationwide study confirmed the need for monitoring the GBS epidemiology in non-pregnant adults through continuous surveillance of GBS infections.

Validity of reducing blood culture incubation time for the BD BACTEC FX blood culture system considering microbiological and clinical aspects

IntroductionA blood culture (BC) test is vital for diagnosing bacteremia in clinical practice. Although incubation time varies among automated BC systems, 4–5 days is deemed to be sufficient time for the BD BACTEC FX blood culture system. This study compared the clinical and microbiological characteristics of true-positive BC samples on day 5 with those within 4 days to reduce missed true bacteremia cases. MethodsWe conducted a retrospective study of blood cultures from hospitalized patients between April 2020 and April 2023 at a tertiary care hospital in Japan. ResultsIn total, 12,342 BC sets were collected from 6,567 patients. Gram-positive bacilli other than Bacillus spp. and Corynebacterium spp., non-albicans Candida, and yeasts other than Candida spp. were detected more frequently in BC-positive patients on day 5 than in those within 4 days. The gastrointestinal tract was the portal of entry more frequently on day 5 than within 4 days (25 % vs. 4 %, p = 0.006). ConclusionA 4-day incubation period is sufficient for the BD BACTEC FX blood culture system under routine conditions. However, a 5-day incubation period may be warranted when low pathogenicity is suspected or the gastrointestinal tract is suspected as the portal of entry.

Lacticaseibacillus paracasei Bacteremia Associated With Probiotic Use in a Child With Hypoganglionosis: Case Report and Literature Review.

Probiotics are generally considered safe and used to improve intestinal function. Here, we report a Lacticaseibacillus paracasei bacteremia case in an 8-month-old girl administered probiotics containing L. paracasei after jejunostomy for hypoganglionosis. The patient had persistent bacteremia with L. paracasei and was treated with antimicrobial therapy. The isolate from the blood culture was genetically indistinguishable to the strain contained in probiotics. Bacteremia risk should be considered before probiotic use in patients with underlying compromised immune systems or intestinal integrity.

A Case of Raoultella Ornithinolytica Cholangitis in A Liver Transplant Recipient.

We present the first documented case of Raoultella ornithinolytica bacteraemia in a patient with liver transplantation. R. ornithinolytica is a Gram-negative anaerobic bacterium found in aquatic environments in fish and birds, and is source of nosocomial infection causing pneumonia, enteritis, cholangitis or urinary infections, associated with surgical interventions in a hospital setting. A 44-year-old female presented with a 2-day history of fever, rigors, and headache. Her past medical history was significant for having received three orthotopic liver transplants due to Wilson's disease over a 20-year period. Her physical examination was unremarkable besides stigmata of prior liver transplantation. Blood tests revealed mild elevations in liver function markers and raised inflammatory markers. R. ornithinolytica was eventually isolated from blood cultures. Subsequent magnetic resonance cholangiopancreatography (MRCP) demonstrated new left intrahepatic ductal dilation with heterogeneous peripheral enhancement. The proximal location of the cholangitis explained the lack of abdominal pain or tenderness. The patient was treated with appropriate antibiotic therapy and cultures were negative on day 2. The patient recovered without further intervention. Seldom encountered R. ornithinolytica is uncommonly pathogenic but should be considered in patients receiving immunosuppressants and those with complex surgical anatomy. This is the first case of Raoultella cholangitis in a liver transplant recipient described in the literature.Atypical clinical presentation and atypical infections are common in this patient group.Cholangitis should be suspected in all liver transplant recipients due to immunosuppression.

Clinical outcome of ampicillin or ampicillin/sulbactam versus glycopeptides in ampicillin-susceptible Enterococcus faecalis/faecium bacteremia: a 10-year retrospective cohort study

BackgroundGlycopeptides for ampicillin-susceptible Enterococcus faecalis/faecium bacteremia are readily prescribed depending on the severity of the condition. However, there is limited data on the outcomes of glycopeptide use compared to ampicillin-containing regimens for ampicillin-susceptible E. faecalis/faecium bacteremia. From an antibiotic stewardship perspective, it is important to determine whether the use of glycopeptides is associated with improved clinical outcomes in patients with ampicillin-susceptible E. faecalis/faecium bacteremia.MethodsThis retrospective cohort study was conducted at a university-affiliated hospital between January 2010 and September 2019. We collected data from patients with positive blood cultures for Enterococcus species isolates. The clinical data of patients who received ampicillin-containing regimens or glycopeptides as definitive therapy for ampicillin-susceptible E. faecalis/faecium bacteremia were reviewed. Multivariate logistic regression analysis was performed to identify risk factors for 28-day mortality.ResultsAmpicillin-susceptible E. faecalis/faecium accounted for 41.2% (557/1,353) of enterococcal bacteremia cases during the study period. A total of 127 patients who received ampicillin-containing regimens (N = 56) or glycopeptides (N = 71) as definitive therapy were included in the analysis. The 28-day mortality rate was higher in patients treated with glycopeptides (19.7%) than in those treated with ampicillin-containing regimens (3.6%) (p = 0.006). However, in the multivariate model, antibiotic choice was not an independent predictor of 28-day mortality (adjusted OR, 3.7; 95% CI, 0.6–23.6).ConclusionsGlycopeptide use was not associated with improved mortality in patients with ampicillin-susceptible E. faecalis/faecium bacteremia. This study provides insights to reduce the inappropriate use of glycopeptides in ampicillin-susceptible E. faecalis/faecium bacteremia treatment and promote antimicrobial stewardship.

Retrospective analysis of Acinetobacter baumannii bacteraemia risk factors, complications and mortality in a tertiary university hospital in Saudi Arabia.

Introduction. There are many multidrug-resistant isolates of the nosocomial pathogen, Acinetobacter baumannii, causing severe healthcare-acquired infections in terminally ill patients with high mortality and morbidity rates. Aim. This study aims to retrospectively analyse A. baumannii bacteraemia (ABB) cases in Saudi Arabia, where the information is sparse regarding the prevalence, risk factors, clinical disease, antibiotic regimen, antibiotic susceptibility, treatment outcomes and mortality associated with this infection. Methods. A retrospective chart review was conducted between 1 January 2015 and 31 December 2022 to identify all patients aged 14 years and above with ABB. Demographic and clinical data, as well as results from laboratory analyses, were collected from patients' electronic charts. Statistical analyses were performed on the data to identify factors associated with 90-day mortality. Results. Of the 122 ABB cases, 71 (63.4%) died. The factors that were found to be associated with 90-day mortality were the Charlson Comorbidity Index, Pitt bacteraemia score, quick Sequential Organ Failure Assessment score (P<0.001 for each), hospital ward (P<0.02), short duration of antibiotic treatment (P<0.01) and higher age (P<0.05). The most common source of infection was central line-associated bloodstream infection in 52.7%. Also associated with mortality were inappropriate antimicrobial therapy (P<0.02) and empirical use of colistin (P<0.05). In many patients, ABB was caused by carbapenem-resistant A. baumannii [(CRAB), 69.6%], and 74.4% of those patients died. Conclusion. To prevent ABB-associated mortality, an appropriate regimen and duration of treatment are necessary. Hospitals should also practice proper hygiene to prevent the spread of ABB. CRAB is a growing threat in hospitals in Saudi Arabia, especially in the critical care setting, and carries a very high risk of mortality.

Fitness factor genes conserved within the multi-species core genome of Gram-negative Enterobacterales species contribute to bacteremia pathogenesis.

There is a critical gap in knowledge about how Gram-negative bacterial pathogens, using survival strategies developed for other niches, cause lethal bacteremia. Facultative anaerobic species of the Enterobacterales order are the most common cause of Gram-negative bacteremia, including Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Citrobacter freundii, and Enterobacter hormaechei. Bacteremia often leads to sepsis, a life-threatening organ dysfunction resulting from unregulated immune responses to infection. Despite a lack of specialization for this host environment, Gram-negative pathogens cause nearly half of bacteremia cases annually. Based on our existing Tn-Seq fitness factor data from a murine model of bacteremia combined with comparative genomics of the five Enterobacterales species above, we prioritized 18 conserved fitness genes or operons for further characterization. Mutants were constructed for all genes in all five species. Each mutant was used to cochallenge C57BL/6 mice via tail vein injection along with each respective wild-type strain to determine competitive indices for each fitness gene. Five fitness factor genes, when mutated, attenuated mutants in four or five species in the spleen and liver (tatC, ruvA, gmhB, wzxE, arcA). Five additional fitness factor genes or operons were validated as outcompeted by wild-type in three, four, or five bacterial species in the spleen (xerC, prc, apaGH, atpG, aroC). Overall, 17 of 18 fitness factor mutants were attenuated in at least one species in the spleen or liver. Together, these findings allow for the development of a model of bacteremia pathogenesis that may include future targets of therapy against bloodstream infections.

Disease-associated microbiome signature species in the gut.

There is an accumulation of evidence that the human gut microbiota plays a role in maintaining health, and that an altered gut microbiota (sometimes called dysbiosis) associates with risk for many noncommunicable diseases. However, the dynamics of disease-linked bacteria in the gut and other body sites remain unclear. If microbiome alterations prove causative in particular diseases, therapeutic intervention may be possible. Furthermore, microbial signature taxa have been established for the diagnosis of some diseases like colon cancer. We identified 163 disease-enriched and 98 disease-depleted gut microbiome signature taxa at species-level resolution (signature species) from 10 meta-analyses of multiple diseases such as colorectal cancer, ulcerative colitis, Crohn's disease, irritable bowel syndrome, pancreatic cancer, and COVID-19 infection. Eight signature species were enriched and nine were depleted across at least half of the diseases studied. Compared with signature species depleted in diseases, a significantly higher proportion of disease-enriched signature species were identified as extra-intestinal (primarily oral) inhabitants, had been reported in bacteremia cases from the literature, and were aerotolerant anaerobes. These findings highlight the potential involvement of oral microbes, bacteremia isolates, and aerotolerant anaerobes in disease-associated gut microbiome alterations, and they have implications for patient care and disease management.

Associations between maternal bacteremia during the peripartum period and early-onset neonatal sepsis: a retrospective cohort study

IntroductionEarly-onset neonatal sepsis (EONS) significantly impacts neonatal morbidity and mortality, with maternal bacteremia during the peripartum period being a potential risk factor. This study aims to explore the association between peripartum maternal bacteremia and EONS.MethodsA retrospective cohort study at the Women's Wellness and Research Center in Doha, Qatar (2015–2019) compared women with and without bacteremia, based on blood cultures taken from up to seven days before to 48 h after delivery, examining the association with EONS.ResultsAmong the 536 maternal blood cultures analyzed, 102 (19.0%) were positive. The most prevalent organisms were Group B streptococcus (GBS) (39.2%), followed by Escherichia coli (14.7%) and anaerobes (10.8%). Neonates from bacteremic mothers had lower birth weights (2913 ± 86 g vs. 3140 ± 745 g; MD 227.63 g; 95% CI 61.72 − 393.55; p = 0.007), required more resuscitation (27.5% vs. 13.2%; OR 2.48; 95% CI 1.48 − 4.17; p < 0.001), and received antibiotics for ≥ 7 days more frequently (41.2% vs. 16.6%; OR 3.51; 95% CI 2.20 − 5.62; p < 0.001) compared to those from non-bacteremic mothers. Maternal Gram-positive (GP) organisms were more commonly isolated in term gestation (67.9%) compared to Gram-negative (GN) (22.2%) and anaerobic bacteremias (9.9%). During intrapartum, GP bacteremia was predominant (67.1%) vs. GN (21.4%) and Anaerobes (11.4%), with GN bacteremia being more common in postpartum samples. Culture-proven EONS occurred in 0.75% of the cohort, affecting 3.9% of infants from bacteremic mothers vs. none in controls (OR 2.34; 95% CI 1.27 − 4.31; p < 0.001). Culture-negative EONS appeared in 14.7% of infants from bacteremic mothers vs. 7.8% in controls (OR 2.02; 95% CI, 1.05 − 3.88; p = 0.03). Among 40 cases of maternal GBS bacteremia, culture-proven GBS EONS occurred in 3 neonates (7.5%), all from mothers with negative GBS screening, compared to none in the control group. A strong association was found between EONS and maternal bacteremia due to any organism (aOR 2.34; 95% CI, 1.24 − 4.41; p = 0.009), GP bacteremia (aOR 3.66; 95% CI, 1.82 − 7.34; p < 0.001), or GBS (aOR 5.74; 95% CI, 2.57 − 12.81; p < 0.001). Bacteremia due to GN and Anaerobic organisms were not associated with EONS. Chorioamnionitis and antepartum fever were independent predictors for EONS associated with significant bacterial isolates.ConclusionThis study underscores the significant impact of maternal GP bacteremia, particularly from GBS, on EONS. The strong association highlights the need for vigilant monitoring and interventions in pregnancies complicated by bacteremia to reduce adverse neonatal outcomes.

Understanding bacterial diversity, infection dynamics, prevention of antibiotic resistance: an integrated study in an Algerian hospital context.

Bacterial infections, particularly bacteremia, urinary tract infections (UTIs), and pus infections, remain among hospitals' most worrying medical problems. This study aimed to explore bacterial diversity, infection dynamics, and antibiotic resistance profiles of bacterial isolates. We analyzed data from 1750 outpatients and 920 inpatients, of whom 1.6% and 8.47% respectively had various bacterial infections. The analysis revealed that UTIs were the most prevalent at 41.01%, particularly affecting women. UTIs also showed a distinct distribution across admission departments, notably in emergency (23.07%) and pediatric (14.10%) units. The most frequently isolated microorganisms were Escherichia coli (E. coli), followed by Klebsiella ornithinolytica. Skin infections followed UTIs, accounting for 35.88% of cases, more prevalent in men, with Staphylococcus aureus (S. aureus) being the primary pathogen (57%). Gram-negative bacteria (GNB) like E. coli and Pseudomonas aeruginosa contributed significantly to skin infections (43%). Bacteremia cases constituted 11.52% of bacterial infections, predominantly affecting women (67%) and linked to GNB (78%). A comparative study of antibiotic susceptibility profiles revealed more pronounced resistance in GNB strains isolated from inpatients, particularly to antibiotics such as Amoxicillin/clavulanic acid, Tetracyclin, Gentamicin, Chloramphenicol, and Ampicillin. In contrast, strains from ambulatory patients showed greater resistance to Colistin. Gram-positive bacteria from hospitalized patients showed higher resistance to quinolones and cephalosporins, while ambulatory strains showed high resistance to aminoglycosides, macrolides, fluoroquinolones, and penicillin. Furthermore, these analyses identified the most effective antibiotics for the empirical treatment of both community-acquired and nosocomial infections. Ciprofloxacin, aztreonam, and amikacin exhibited low resistance rates among GNB, with gentamicin and chloramphenicol being particularly effective for community-acquired strains. For S. aureus, ciprofloxacin, rifampicin, and cefoxitin were especially effective, with vancomycin showing high efficacy against community-acquired isolates and fosfomycin and chloramphenicol being effective for hospital-acquired strains. These results are essential for guiding antibiotic therapy and improving clinical outcomes, thus contributing to precision medicine and antimicrobial stewardship efforts.

Abstract We127: Infective Endocarditis in COVID-19 - An Unusual Suspect

Introduction: The COVID-19 pandemic globally overwhelmed healthcare systems and the complications associated with this illness have contributed to poor outcomes. The hypercoagulable state associated with COVID-19 is well recognized in the literature. Thromboembolic complications such as left ventricular thrombus (LVT), deep venous thrombosis (DVT) and pulmonary embolism (PE) have been increasingly reported. Dhakal et al. published an association between COVID-19 and cardiovascular disease, including possible complication by infective endocarditis (IE) which was confirmed by Amir et al. reporting the first case. Since then, there have been few reported cases. We present a case of COVID-19 in a patient who developed LVT, complicated by non-valvular IE by an underreported organism, Granulicatella adiacens. Case Presentation: A 55-year-old male with history of dental caries, provoked DVT/PE, NSTEMI x2 and STEMI in-stent restenosis requiring thrombectomy presented to the hospital with a 2-day history of shortness of breath, fatigue, cough, change in mentation and right-sided weakness. He tested positive for COVID-19 by NAAT. CXR revealed cardiomegaly and multiple bilateral infiltrates. CT head demonstrated acute ischemic stroke of the left occipital, parietal and posterior temporal lobes, also confirmed on MRI. CTA neck showed 30% stenosis of left ICA. Blood cultures x2 resulted positive for G. adiacens. Echocardiogram was obtained, demonstrating reduced EF of 35% and the presence of a large, 2.7 x 2.2cm mobile thrombus in the apical-septal region of the left ventricle, not visualized on previous echocardiogram 6 months earlier. Methods: Data was collected from direct patient care and electronic medical records. Discussion: G. adiacens is a fastidious gram-positive coccus, part of the nutritionally variant streptococci (NVS) species, and part of the normal oral and gastrointestinal flora. It is also found in dental plaques and endodontic abscesses. NVS account for less than 5% of cases of bacteremia and IE. G. adiacens account for even fewer cases. Two separate meta-analyses conducted by Quintero-Martinez et al. and George et al. failed to reveal any cases of IE attributable to G. adiacens in the setting of COVID-19 infection. In conclusion, we believe that the hypercoagulable state of COVID-19 infection led to endocardial damage and development of LVT, thereby creating a nidus for microorganism adherence from underlying dental carries resulting in thromboembolic stroke.

The Impact of Information Relevancy and Interactivity on Intensivists' Trust in a Machine Learning-Based Bacteremia Prediction System: Simulation Study.

The exponential growth in computing power and the increasing digitization of information have substantially advanced the machine learning (ML) research field. However, ML algorithms are often considered "black boxes," and this fosters distrust. In medical domains, in which mistakes can result in fatal outcomes, practitioners may be especially reluctant to trust ML algorithms. The aim of this study is to explore the effect of user-interface design features on intensivists' trust in an ML-based clinical decision support system. A total of 47 physicians from critical care specialties were presented with 3 patient cases of bacteremia in the setting of an ML-based simulation system. Three conditions of the simulation were tested according to combinations of information relevancy and interactivity. Participants' trust in the system was assessed by their agreement with the system's prediction and a postexperiment questionnaire. Linear regression models were applied to measure the effects. Participants' agreement with the system's prediction did not differ according to the experimental conditions. However, in the postexperiment questionnaire, higher information relevancy ratings and interactivity ratings were associated with higher perceived trust in the system (P<.001 for both). The explicit visual presentation of the features of the ML algorithm on the user interface resulted in lower trust among the participants (P=.05). Information relevancy and interactivity features should be considered in the design of the user interface of ML-based clinical decision support systems to enhance intensivists' trust. This study sheds light on the connection between information relevancy, interactivity, and trust in human-ML interaction, specifically in the intensive care unit environment.