Paired Blood Cultures Research Articles

AEROBIC BLOOD CULTURES AND COMPARISON TO CLINICAL FINDINGS OF FREE-RANGING GREEN TURTLES (CHELONIA MYDAS) IN EAST CENTRAL FLORIDA.

Positive blood cultures have been identified in debilitated, stranded, and deceased green turtles (Chelonia mydas), suggestive of septicemia. Interpretation of these results is often difficult because multiple studies have previously identified bacteremia in clinically healthy reptiles. In this study, paired blood cultures and skin cultures obtained after aseptic preparation of the venipuncture site were collected from 50 immature free-ranging green turtles from Port Canaveral, Florida. Blood culture results were compared with health status (apparently healthy versus unhealthy, based on physical examination findings and appropriate body condition), date of collection, presence of external fibropapillomatosis, healed or unhealed injuries, and presence of barnacles. Weight, body condition score, body condition index, morphometric measures, volume of blood collected, and body temperature were compared between blood culture-positive and blood culture-negative turtles. Positive blood cultures were identified in 14% (7 of 50) of all turtles, including 15.6% (5 of 32) of apparently healthy turtles. Vibrio spp., Bacillus megaterium, Cellulomonas sp., and Staphylococcus pasteuri were isolated in blood culture from apparently healthy individuals. There was a significant association (P = 0.048) between positive skin cultures and positive blood cultures, but isolates obtained were consistently different between paired results. There was no significant association (P > 0.05) between blood culture results and health status, evidence of healed or unhealed injuries, external fibropapillomatosis, or presence of barnacles. Based on the results of this study, positive blood cultures suggestive of nonclinical bacteremia may be present in apparently healthy green turtles. The results of this study will aid the attending clinician in interpretation of blood culture results of apparently healthy or presumed septicemic captive and rehabilitating green turtles as part of the conservation and population recovery of this threatened species.

Rise in the Pathogenic Status of Coagulase-Negative Staphylococci Causing Bloodstream Infection.

Coagulase-negative staphylococci (CoNS) are one of the frequently isolated bacteria from blood cultures. Since they are part of the normal skin flora, they were previously considered contaminants. But now, they can be considered as established pathogens causing bloodstream infection (BSI). This study aims to estimate the prevalence of CoNS in BSI cases. This study was conducted at the Microbiology Department, All India Institute of Medical Sciences (AIIMS), Raipur, India, for eight months (January 2022 to August 2022). Data were collected retrospectively from medical and laboratory records. Paired blood cultures from 5085 clinically suspected sepsis cases were subjected to aerobic culture for five days in the BacT ALERT 3D system. Pathogenicity was established after recovery of CoNS from paired blood cultures of symptomatic patients. CoNS were isolated from 2.35% of patients, the most common species being Staphylococcus haemolyticus (51.67%). About 90% of isolates were methicillin-resistant. All the isolates were susceptible to linezolid, teicoplanin, and vancomycin, except one isolate of S. haemolyticus which was intermediate to vancomycin. Minimum inhibitory concentration (MIC) 50 and MIC 90 for vancomycin were 1 ug/ml and 2 ug/ml, respectively. Conclusion: Paired blood cultures are necessary to determine the pathogenicity of CoNS in BSI cases. A high prevalence of methicillin resistance, accompanied by high resistance rates to other non-beta lactam antibiotics, warrants the strict implementation of antimicrobial stewardship practices.

Metagenomic next-generation sequencing of plasma cell-free DNA improves the early diagnosis of suspected infections

BackgroundMetagenomic next-generation sequencing (mNGS) could improve the diagnosed efficiency of pathogens in bloodstream infections or sepsis. Little is known about the clinical impact of mNGS test when used for the early diagnosis of suspected infections. Herein, our main objective was to assess the clinical efficacy of utilizing blood samples to perform mNGS for early diagnosis of suspected infections, as well as to evaluate its potential in guiding antimicrobial therapy decisions.MethodsIn this study, 212 adult hospitalized patients who underwent blood mNGS test in the early stage of suspected infections were enrolled. Diagnostic efficacy of mNGS test and blood culture was compared, and the clinical impact of mNGS on clinical care was analyzed.ResultsIn our study, the total detection rate of blood mNGS was significantly higher than that of culture method (74.4% vs. 12.1%, P < 0.001) in the paired mNGS test and blood culture. Blood stream infection (107, 67.3%) comprised the largest component of all the diseases in our patients, and the detection rate of single blood sample subgroup was similar with that of multiple type of samples subgroup. Among the 187 patients complained with fever, there was no difference in the diagnostic efficacy of mNGS when blood specimens or additional other specimens were used in cases presenting only with fever. While, when patients had other symptoms except fever, the performance of mNGS was superior in cases with specimens of suspected infected sites and blood collected at the same time. Guided by mNGS results, therapeutic regimens for 70.3% cases (149/212) were changed, and the average hospitalized days were significantly shortened in cases with the earlier sampling time of admission.ConclusionIn this study, we emphasized the importance of blood mNGS in early infectious patients with mild and non-specific symptoms. Blood mNGS can be used as a supplement to conventional laboratory examination, and should be performed as soon as possible to guide clinicians to perform appropriate anti-infection treatment timely and effectively. Additionally, combining the contemporaneous samples from suspected infection sites could improve disease diagnosis and prognoses. Further research needs to be better validated in large-scale clinical trials to optimize diagnostic protocol, and the cost-utility analysis should be performed.

Evaluation of the Specificity of the 2023 Duke-International Society of Cardiovascular Infectious Diseases Classification for Infective Endocarditis.

The 2023 Duke-ISCVID (International Society of Cardiovascular Infectious Diseases) classification is a new diagnostic tool for infective endocarditis, updating the 2000 modified Duke and the 2015 European Society for Cardiology (ESC) classifications. In comparison, its sensitivity is higher; however, its specificity remains to be evaluated and compared to that of the 2 other classifications in endocarditis suspected patients. We retrospectively collected the characteristics of patients hospitalized in Bichat University's Hospital, Paris, in 2021, who had been evaluated for clinical suspicion of endocarditis, have had at least a transthoracic echocardiography, 2 pairs of blood cultures, 3-month follow-up and in whom endocarditis diagnosis was finally rejected. All patients were classified by 2000 modified Duke, 2015 ESC and 2023 Duke-ISCVID, as though the endocarditis diagnosis had not been rejected. In total, 130 patients' charts were analyzed. Mean age was 62 years, 84 (64.6%) were male, 39 (30.0%) had prosthetic cardiac valve or valve repair, 21 (16.2%) cardiac implanted electronic device, and 30 (23.1%) other cardiac conditions. Overall, 5, 2, and 5 patients were falsely classified as definite endocarditis with the 2000 modified Duke, 2015 ESC, and 2023 Duke-ISCVID classifications, respectively. The corresponding specificities were 96.2% (95% confidence interval [CI] [90.8%, 98.6%]), 98.5% (95% CI [93.9%, 99.7%]), and 96.2% (95% CI [90.8%, 98.6%]). The rates of possible endocarditis were of 38%, 35%, and 35% in the 3 classifications, respectively. The 2023 Duke-ISCVID classification is highly specific for ruling out the diagnosis of definite infective endocarditis in patients who had been evaluated for IE.

Narrative Review and Diagnostic Performance Assessment of Paired Blood Cultures in Children with Cancer and Febrile Neutropenia: An Analysis of Four Studies

Children receiving cancer treatment face a heightened risk of bloodstream infections, posing challenges in care. Accurate diagnosis is crucial, and paired blood cultures (BC) from central venous catheter (CVC) and peripheral vein (PV) are a promising diagnostic approach. This review assesses the diagnostic accuracy and clinical utility of pediatric paired BC in children with cancer. A PubMed search (2003-2023) yielded 1042 titles; four articles meeting inclusion criteria were included. Studies on diagnostic accuracy or clinical utility of pediatric paired BC in ages 0-18 were reviewed by two independent assessors. Data extraction covered study characteristics, demographics, and diagnostic parameters. Observing 825 positive paired BC with a 23.5% false-positive rate, PV exclusively detected bacteremia in 22.7%, while CVC culture exclusively detected it in 54.7%. Both methods detected bacteremia in 54.0%. Variable sensitivity, specificity, PPV, and NPV across studies necessitate nuanced interpretation. PV showed higher sensitivity, while CVC exhibited higher specificity. Method choice should align with clinical context, urgency, and potential consequences. False positives, particularly with CVC, underscore the need for cautious clinical decision-making. Personalized approaches balancing clinical and diagnostic considerations are essential. Collecting paired samples aids in avoiding false positives, reducing unnecessary interventions, but may involve causing pain.

Host response signature trends in persistent bacteraemia and metastatic infection due to Staphylococcus aureus and Gram-negative bacilli: a prospective multicentre observational study

Background A prompt diagnosis of bacteraemia and sepsis is essential. Markers to predict the risk of persistent bacteraemia and metastatic infection are lacking. SeptiCyte RAPID is a host response assay stratifying patients according to the risk of infectious vs sterile inflammation through a scoring system (SeptiScore). In this study we explore the association between SeptiScore and persistent bacteraemia as well as metastatic and persistent infection in the context of a proven bacteraemia episode. Methods This is a prospective multicentre observational 14-month study on patients with proven bacteraemia caused by Staphylococcus aureus or Gram-negative bacilli. Samples for assessment by SeptiCyte were collected with paired blood cultures for 4 consecutive days after the index blood culture. Results We included 86 patients in the study, 40 with S. aureus and 46 with Gram-negative bacilli bacteraemia. SeptiScores over the follow-up were higher in patients with Gram-negative compared to S. aureus bacteraemia (median 6.4, IQR 5.5–7.4 vs 5.6 IQR 5.1–6.2, p = 0.002). Higher SeptiScores were found to be associated with positive blood cultures at follow-up (AUC = 0.86, 95%CI 0.68–1.00) and with a diagnosis of metastatic infection at day 1 and 2 of follow-up (AUC = 0.79, 95%CI 0.57–1.00 and AUC = 0.82, 95%CI 0.63–1.00 respectively) in the context of Gram-negative bacteraemia while no association between SeptiScore and the outcomes of interest was observed in S. aureus bacteraemia. Mixed models confirmed the association of SeptiScore with positive blood cultures at follow-up (p = 0.04) and metastatic infection (p = 0.03) in the context of Gram-negative bacteraemia but not S. aureus bacteraemia after adjusting for confounders. Conclusions SeptiScores differ in the follow-up of S. aureus and Gram-negative bacteraemia. In the setting of Gram-negative bacteraemia SeptiScore demonstrated a good negative predictive value for the outcomes of interest and might help rule out the persistence of infection defined as metastatic spread, lack of source control or persistent bacteraemia.

Epidemiological and bacteriological profile of sepsis in burns patients: A report from tertiary care hospital, India

Background: Burns are one of the most prevalent and mortifying forms of trauma. Patients burn with significant thermal injury require immediate intensive care unit (ICU) care to minimize morbidity and mortality. Burns patients are generally more predisposed to sepsis because of two main reasons, i.e., burn wound infection and catheter-related bloodstream infection (CRBSI). Due to extensive skin barrier disruption and an alteration in the cellular and humoral immune responses burn wounds has a much higher incidence of sepsis as compared to other forms of trauma. Aims and Objectives: The present study was undertaken to study the bacteriological profile and sources of sepsis in burns patients and their antimicrobial susceptibility pattern. Materials and Methods: It is a prospective observational study conducted in the Department of Burns, Plastic and Maxillofacial Surgery, ICU and Department of Microbiology of a tertiary care hospital, Uttar Pradesh, India, between January 2020 and June 2022. Adult patients with 30–70% of total body surface area burns with central venous catheter (CVC) inserted during ICU admission were enrolled in the study. The presence of clinical sepsis in the burn patients was evaluated using the American Burn Association Sepsis criteria. For all patients with suspected clinical sepsis, paired blood cultures were collected simultaneously; one from the CVC and another from a peripheral site and were sent for bacteriological culture. Blood culture samples were processed as per standard procedures. CRBSI was defined if the same organism was isolated in paired blood cultures. Burn wound biopsy was sent for quantitative culture and 105 organisms/g of tissue were considered significant. Results: In the present study, the overall incidence of clinical sepsis was 28.4% (39/137), out of which 48.7% of cases were found to be due to CRBSI and the most common organism involved was Klebsiella spp. (42.1%), 33.3% of cases were due to burn wound sepsis and the most common organism involved was Pseudomonas spp. (61.5%); and 18.0% of cases were those in which no known source could be found. Possible explanations for these cases could be sepsis without bacteremia due to endotoxins and Gram-negative endotoxemia. Conclusion: To find out microorganisms causing burn wound infection by culture and provide suitable antibiotics according to their antibiotic sensitivity patterns helping us in managing these infection and decreasing overall morbidity and mortality in burn patients.

Usefulness of daptomycin lock therapy in children with catheter-related bacteremia after failed vancomycin lock therapy

PurposeCatheter-related bacteremia (CRB) is a significant cause of morbidity, resource expenditure and prolonged hospital stays in patients with long-term catheters, whose numbers have increased considerably in recent years. Antibiotic lock therapy reaches high concentrations in the catheter, allowing good penetration into the biofilm, being vancomycin the most commonly used one in gram-positive infections. Several authors have recently reported the superior in vitro efficacy of daptomycin compared with vancomycin, especially for eradicating biofilms. Although there is some data on the use of daptomycin for antibiotic lock in animal models and adults, there are no data on its use in children.MethodsA descriptive study was conducted in a tertiary hospital, including patients younger than 16 years in whom daptomycin lock therapy was employed between 2018 and 2022.ResultsWe report three pediatric patients in whom CRB was confirmed on admission by paired blood cultures positive for CoNS sensitive to vancomycin, daptomycin and linezolid. All patients started vancomycin lock therapy and systemic antibiotic therapy with proven sensitivity for the isolated bacteria, without achieving negative blood cultures. Due to the persistence of positive cultures, vancomycin lock therapy was replaced by daptomycin, and blood cultures turned negative, with no relapses or need for catheter removal.ConclusionThe use of daptomycin lock therapy could be considered in children with CoNS catheter infection, especially when other antibiotic lock therapy had failed.

Risk factors for contaminated blood cultures in the emergency department: A prospective cohort study

BackgroundWe aimed to determine risk factors associated with rates of contaminated blood cultures in the emergency department (ED). MethodsThis single-center, cohort study of 1098 consecutive patients ≥ 20 years of age was performed in the ED of university hospital over a 26-month period. ResultsWe analyzed 2096 pairs of blood cultures. Potential contamination was identified in 172 (8.2%) of the 2096 pairs of blood cultures. Multivariate analysis revealed more frequent contamination when puncture sites were disinfected with povidone-iodine (PVI) than with alcohol/chlorhexidine gluconate (adjusted odds ratio, 7.13; 95% confidence interval [CI], 4.8–10.7; P < 0.001). Femoral and central venous catheters showed more frequent contamination than peripheral venous sites. Blood collection by first- or second-year residents did not show an increase in contaminated blood cultures. ConclusionsRates of contaminated blood cultures were significantly associated with PVI and specific sites, but were not significantly associated with blood collection by residents.

Utility of Differential Time to Positivity in Diagnosing Central Line Associated Bloodstream Infections: A Systematic Review and Meta-Analysis.

Differential time to positivity (DTP), typically defined as pathogen growth at least two hours earlier from catheter vs paired peripheral blood cultures, is sometimes used to diagnose central line associated bloodstream infections (CLABSIs). Previous studies assessing DTP, however, have been small, provided conflicting results, and have not assessed heterogeneity across important subgroups. We conducted a systematic review of the diagnostic characteristics of DTP for CLABSI, using MEDLINE, Embase, Web of Science, CINAHL, LILACS, AMED and the Cochrane database. Studies were eligible for inclusion if they reported sensitivities, specificities, predictive values, likelihood ratios, or 2x2 tables of DTP for diagnosing CLABSI. Extracted data were analyzed by creating forest plots, performing bivariate model meta-analysis, and assessing quality using QUADAS-2. Our search identified 274 records of which 23 met criteria for meta-analysis. Among 2,526 suspected CLABSIs, DTP demonstrated a summary sensitivity of 81.3% (95% CI 72.8-87.7%), specificity of 91.8% (95% CI 84.5-95.8%), positive likelihood ratio of 9.89 (95% CI 5.14-19.00), and negative likelihood ratio of 0.20 (95% CI 0.14-0.30). Covariate analysis based on catheter duration, study design, and patient immune status demonstrated no significant differences. However, DTP performed worse for Staphylococcus aureus (low sensitivity but high specificity) and Candida (high sensitivity but low specificity) compared to other organisms. DTP performs well in ruling CLABSIs in or out. Obtaining paired catheter and peripheral blood cultures for DTP when the infectious source is unclear may prevent unnecessary line removal and diagnostic tests, although this needs to be balanced against potentially higher contamination rates from catheter cultures.

Contamination of Blood Cultures From Arterial Catheters and Peripheral Venipuncture in Critically Ill Patients: A Prospective Multicenter Diagnostic Study

Collecting blood cultures from indwelling arterial catheters is an attractive option in critically ill adult patients when peripheral venipuncture is difficult. However, whether the contamination proportion of blood cultures from arterial catheters is acceptable compared with that from venipuncture is inconclusive. Is contamination of blood cultures from arterial catheters noninferior to that from venipuncture in critically ill adult patients with suspected bloodstream infection? In this multicenter prospective diagnostic study conducted at five hospitals,we enrolled episodes of paired blood culture collection, each set consisting of blood drawn from an arterial catheter and another by venipuncture, were obtained from critically ill adult patients with cilinical indication. The primary measure was the proportion of contamination, defined as the number of false-positive results relative to the total number of procedures done. The reference standard for true bloodstream infection was blinded assessment by infectious disease specialists. We examined the noninferiority hypothesis that the contamination proportion of blood cultures from arterial catheters did not exceed that from venipuncture by 2.0%. Of 1,655 episodes of blood culture from December 2018 to July 2021, 590 paired blood cultureepisodes were enrolled, and 41 of the 590 episodes (6.9%) produced a true bloodstream infection. In blood cultures from arterial catheters, 33 of 590 (6.0%) were positive, and two of 590 (0.3%) were contaminated; in venipuncture, 36 of 590 (6.1%) were positive, and four of 590 (0.7%) were contaminated. The estimated difference in contamination proportion (arterial catheter - venipuncture) was -0.3%(upper limit of one-sided 95%CI,+0.3%). The upper limit of the 95%CI did not exceed the predefined margin of+2.0%, establishing noninferiority (P for noninferiority< .001). Obtaining blood cultures from arterial catheters is an acceptable alternative to venipuncture in critically ill patients. University Hospital Medical Information Network Center (UMIN-CTR); No.: UMIN000035392; URL: https://center6.umin.ac.jp/.

Usefulness of differential time to positivity between catheter and peripheral blood cultures for diagnosing catheter-related bloodstream infection: Data analysis from routine clinical practice in the intensive care unit

PurposeTo assess the accuracy of differential time to positivity (DTP) method for the diagnosis of catheter-related bloodstream infections (CRBSI) in the routine practice of our intensive care unit (ICU). Materials and methodsOver a five-year study period, ICU patients with a central venous catheter in place for ≥48 h and undergoing DTP test with catheter tip culture were analyzed. We investigated: the accuracy of DTP test with the usual threshold of 120 min in confirming the clinical suspicion of CRBSI; the most accurate threshold value of DTP to detect CRBSI; the diagnostic accuracy of the ratio (rather than the difference) between times to positivity. ResultsAmong 278 episodes of paired blood cultures, 13% were CRBSIs. DTP value ≥120 min used for the diagnosis of CRBSI yielded 41% sensitivity and 74% specificity. Performance of DTP values in predicting CRBSI was low (AUC = 0.60 [95%CI: 0.48–0.72]). Cutoff value of the ratio between times to positivity was 0.80, with 46% sensitivity and 79% specificity. ConclusionsThe routine use of the DTP method at any cutoff point has inadequate accuracy in detecting CRBSI in the real every day clinical practice. Not even the ratio between times to positivity seems to be clinically useful.

343. Relevance of Use of Anaerobic Blood Culture Bottle for the Diagnosis of Bacteremia

Abstract Background Blood cultures remain the cornerstone for the diagnosis of bacteremia. Although an anaerobic blood culture bottle can recover facultative and obligate anaerobes, routine use of an anaerobic bottle paired with an aerobic bottle remains controversial. We aimed to evaluate the role of anaerobic bottle for the diagnosis of bacteremia. Methods We conducted a retrospective cohort study in a tertial hospital in Japan from January 2019 to September 2021. Blood culture results were collected from microbiology laboratory records. Blood cultures for which simultaneous pairs of aerobic and anaerobic bottles were collected and from which a single organism was recovered were included. Positive blood cultures were considered as a single episode of bacteremia when obtained within 14 consecutive days. Results A total of 22677 blood cultures were collected, with 22650 bottles were paired. In 2962 paired blood cultures of which one or both bottles were positive, 1079 episodes of clinically significant monomicrobial bacteremia were observed. In these episodes, 898 had a positive aerobic bottle, while 789 had a positive anaerobic bottle, with 608 had both positive bottles. In 181 episodes (16.8%), clinically significant organisms were isolated in an anaerobic bottle without concomitant positive aerobic bottle. In these anaerobic bottles, 146 facultative and 35 obligate anaerobes were recovered. The most common facultative anaerobe was Escherichia coli (30 isolates), followed by Staphylococcus aureus (27 isolates). Bacteroides fragilis (11 isolates) was the most common obligate anaerobe. Conclusion Recovery of clinically significant facultative and obligate anaerobes from anaerobic bottle alone was observed in 17% of episodes, which supports that the routine collection of both aerobic and anaerobic bottles is relevant. Disclosures All Authors: No reported disclosures.

Surveillance of central line associated bloodstream infection (CLABSI) - comparison of current (CDC/NHSN) and modified criteria: A prospective study.

There is a huge load of central line-associated bloodstream infection (CLABSI) being reported in developing countries, with increased mortality and healthcare costs. Effective surveillance is a must to reduce the incidence of CLABSI. The current criteria (Centre for Disease Control and Prevention/National Healthcare Safety Network [CDC/NHSN]) for CLABSI surveillance have their own shortcomings. For diagnosing CLABSI, current CDC/NHSN CLABSI surveillance criteria are laborious and time consuming with low predictive power. Hence, modified criteria have been postulated, which are simple and implementable at resource-constrained setups. The primary objective was to compare modified criteria with CDC criteria. The secondary objective was to determine the prevalence of CRBSI. A total of 98 patients with central line in situ or having the central venous line removed ≤24 hrs prior to the date of the event were enrolled. Paired blood cultures were obtained and results were analyzed using differential time to positivity. The incidence of CLBSI was 8.16% and the device utilization rate was 11.6%. The negative predictive value of both the surveillance criteria was found to be excellent and comparable (96.2% for modified criteria and 97.1% for CDC criteria), therefore both can be used for screening purposes. AUC for current CDC/NHSN criteria was better than modified criteria (0.76 versus 0.66, P < 0.0001), suggesting it to be a better criterion for surveillance of CLABSI. Modified criteria were not superior to CDC/NHSN criteria for surveillance. Thus, there is a scope of improving the modified criteria for the purpose of surveillance. CLBSI load was higher; CLABSI bundle for prevention is thus highly recommended.

Evaluation of the relevance of use of the BD-BACTEC®MycosisIC/F, BD-BACTEC®PlusAerobic/F, BD-BACTEC®Lytic/10 anaerobic/F and BD-BACTEC®PedsPlus/F culture bottle system for fungemia detection: A 4-year retrospective study at the Dijon university hospital, France.

Fungemia is a severe invasive fungal infection that combines rapid progression and a high mortality rate. This type of infection is a vital emergency, and early diagnosis is crucial. Currently, only the BD-BACTEC® Automated Blood Culture System (Becton Dickinson, New Jersey, USA) has a medium specifically dedicated to the detection of fungal agents: the BD-BACTEC®MycosisIC/F bottle. Thus, it is important to assess the performance of the different bottles offered by the BD-BACTEC® Automated Blood Culture System for the diagnosis of fungemia. The aim of this study was to evaluate the performance of the BD-BACTEC® MycosisIC/F culture medium in comparison to bacteriologic culture bottle media for the detection of fungemia in different clinical situations. This retrospective study was conducted over a period of 4 years at the Dijon University Hospital. Three hundred and thirty-one pairs of blood cultures (i.e. a BD-BACTEC® MycosisIC/F culture bottle associated with at least one bacteriologic culture media bottle) were included in this study. We showed that the BD-BACTEC® MycosisIC/F culture bottles performed significantly better (i.e. diagnostic advantage either because it was the only positive bottle of the pair or time to positive result was shorter) than the bacteriological culture bottles in 57.7% (191/331) of cases (p <0.01). Multivariate analysis revealed that BD-BACTEC®MycosisIC/F bottles had better diagnostic performance than BD-BACTEC®Bacteriologic bottles in the context of: (i) the initial versus follow-up diagnostic subgroup, (ii) venipuncture or arterial sampling versus other sampling methods, and (iii) detection of filamentous versus yeast fungi. We concluded that the use of BD-BACTEC® MycosisIC/F culture bottles is a relevant addition to media optimized for routine bacterial detection.

Maternal colonization and early-onset neonatal bacterial sepsis in the Gambia, West Africa: a genomic analysis of vertical transmission

ObjectivesTo define bacterial aetiology of neonatal sepsis and estimate the prevalence of neonatal infection from maternal genital tract bacterial carriage among mother-newborn pairs. MethodsWe carried out a cross-sectional study of newborns with clinical sepsis admitted to three hospitals in the Gambia neonatal wards. Neonatal blood cultures and maternal genital swabs were obtained at recruitment. We used whole-genome sequencing to explore vertical transmission for neonates with microbiologically confirmed bloodstream infection by comparing phenotypically-matched paired neonatal blood cultures and maternal genital tract bacterial isolates. ResultsWe enrolled 203 maternal-newborn pairs. Two-thirds (67%; 137/203) of neonates presented with early-onset sepsis (days 0–6 after birth) of which 26% (36/137) were because of a clinically-significant bacterial pathogen. Blood culture isolates from newborns with early-onset sepsis because of Staphylococcus aureus (n = 5), Klebsiella pneumonia (n = 2), and Enterococcus faecalis (n = 1), phenotypically matched their maternal genital tract isolates. Pairwise single-nucleotide variants comparisons showed differences of 12 to 52 single-nucleotide variants only between maternal and newborn S. aureus isolates, presumably representing vertical transmission with a transmission rate of 14% (5/36). ConclusionsWe found a low prevalence of vertical transmission of maternal genital tract colonization in maternal-newborn pairs for early-onset neonatal sepsis in the West African context. Identifying infection acquisition pathways among newborns is essential to prioritize preventive interventions, which could be targeted at the mother or infection control in the hospital environment, depending on the major pathways of transmission.

P023 Evaluation of Beta-D-glucan assay as a tool for antifungal stewardship at a hospital in Mumbai, India

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectivesClinical evidence suggests that the Beta-D glucan (BDG) test is useful as a tool for antifungal stewardship by helping in discontinuing empiric antifungal therapy. This study was hence initiated with the following objectives: (1) to calculate the percentage of echinocandin prescriptions in patients with a subsequent negative BDG test and the compliance to recommendations for stopping echinocandins for the above prescriptions, (2) to study outcomes in patients where echinocandins were stopped, and (3) to study the total cost savings.MethodsThe study was conducted for a 1-year period from January 2021 to December 2021 in a tertiary care hospital in Mumbai. The antimicrobial stewardship committee recommends sending a serum sample for BDG along with paired blood culture for all patients before starting empirical antifungal therapy. The choice of empiric antifungal therapy at our hospital is echinocandins (caspofungin, micafungin, and anidulafungin). The BDG test was performed using Fungitell® assay (Associates of Cape Cod, Massachusetts) that quantitatively measures 1, 3-β-D-glucan levels which is run twice a week on Wednesday and Saturday. The cut-offs for a negative, indeterminate and positive result are 60 pg/ml, 60-79 pg/ml, and >80 pg/ml respectively. The result of the BDG test and blood culture was promptly informed to the consultant in charge and recommendations were made to discontinue the echinocandin if both tests were negative. The compliance with these recommendations was monitored. The patients in whom the echinocandin was stopped were monitored during their hospital stay or on day 28 after stopping the echinocandin whichever was earlier. The total cost savings [in Indian Rupees (INR) and converted into US Dollars (USD)] were calculated based on an average of 10 days extra therapy with echinocandins.ResultsA total of 337 echinocandins were prescribed in 294 patients and reviewed during the study period; anidulafungin (170, 50%) was the most commonly prescribed echinocandin followed by caspofungin (131, 39%), and micafungin (36, 11%). The BDG result as well as blood fungal cultures were negative for 53 prescriptions in 49 patients (15.7%). The compliance to recommendations for stopping echinocandin in these prescriptions was 100% (53/53). None of these 49 patients had a sterile culture positive for Candida during the follow-up period. A total of 17 patients died, 1 was discharged against medical advice, 19 were discharged and 12 were still in hospital at the end of the follow-up period. No deaths could be attributed to invasive fungal infections at 28-day follow-up. Total cost savings were 6794 440 INR, corresponding to 89 000 USD during the study year.ConclusionBDG test-based stewardship strategy helped in reducing the use of echinocandins with cost savings and no increased risk of invasive fungal infections related to adverse outcomes in patients where echinocandins were discontinued. The universal compliance to recommendations to deescalate could be achieved by constant dialogue between the departments of Clinical Microbiology and Clinical Medicine.

Clinical validation of a multiplex droplet digital PCR for diagnosing suspected bloodstream infections in ICU practice: a promising diagnostic tool

BackgroundDroplet digital PCR (ddPCR) has emerged as a promising tool of pathogen detection in bloodstream infections (BSIs) in critical care medicine. However, different ddPCR platforms have variable sensitivity and specificity for diverse microorganisms at various infection sites. There is still a lack of prospective clinical studies aimed at validating and interpreting the discrepant ddPCR results for diagnosing BSI in intensive care unit (ICU) practice.MethodsA prospective diagnostic study of multiplex ddPCR panels was conducted in a general ICU from May 21, 2021, to December 22, 2021. Paired blood cultures (BCs) and ddPCRs (2.5 h) were obtained synchronously to detect the 12 most common BSI pathogens and three antimicrobial resistance (AMR) genes. Firstly, ddPCR performance was compared to definite BSI. Secondly, clinical validation of ddPCR was compared to composite clinical diagnosis. Sensitivity, specificity, and positive and negative predictive values were calculated. Thirdly, the positive rate of AMR genes and related analysis was presented.ResultsA total of 438 episodes of suspected BSIs occurring in 150 critical patients were enrolled. BC and ddPCR were positive for targeted bacteria in 40 (9.1%) and 180 (41.1%) cases, respectively. There were 280 concordant and 158 discordant. In comparison with BCs, the sensitivity of ddPCR ranged from 58.8 to 86.7% with an aggregate of 72.5% in different species, with corresponding specificity ranging from 73.5 to 92.2% with an aggregate of 63.1%. Furthermore, the rate of ddPCR+/BC− results was 33.6% (147/438) with 87.1% (128 of 147) cases was associated with probable (n = 108) or possible (n = 20) BSIs. When clinically diagnosed BSI was used as true positive, the final sensitivity and specificity of ddPCR increased to 84.9% and 92.5%, respectively. In addition, 40 blaKPC, 3blaNDM, and 38 mecA genes were detected, among which 90.5% were definitely positive for blaKPC. Further, 65.8% specimens were predicted to be mecA-positive in Staphylococcus sp. according to all microbiological analysis.ConclusionsThe multiplexed ddPCR is a flexible and universal platform, which can be used as an add-on complementary to conventional BC. When combined with clinical infection evidence, ddPCR shows potential advantages for rapidly diagnosing suspected BSIs and AMR genes in ICU practice.

Etiological Agent and Their Antibiotic Susceptibility Pattern Causing Adult Septicaemia in a Critically Ill Patients in a Tertiary Care Setting

Objective: To determine bacterial profile in adult sepsis with their antimicrobial susceptibility pattern in our setup.&#x0D; Study Design: Cross-sectional study.&#x0D; Place and Duration of Study: Microbiology Department, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Dec 2018 to Dec 2019.&#x0D; Methodology: Paired blood culture was collected in automated bottles and was processed as per standard protocol. The isolates were further identified and their susceptibility was performed according to Clinical and Laboratory Standards Institute (CLSI) 2019 guidelines.&#x0D; Results: A total of 580 suspected septicaemia cases were taken into consideration. 169 (29.4%) were positive on blood cultures. Among culture-positive samples, Gram-negative bacilli (GNB) accounted for 113 (66.3%) isolates, while the remaining 56 (33.1%) were gram-positive isolates. Within gram-negative isolates, the most common species were 36 (31.8%) Klebsiella pneumonia, followed by 27 (23.8%) Acinetobacter species and 15 (13.2%) Escherichia coli. Multi-drug resistance (MDR) was observed in 98 (86.7%) isolates. Extended-spectrum beta-lactamase production (ESBL) was reported in 73 (64.6%) of enterobacterial. Among 56 Gram-positive bacterial isolates, 25 (44.6%) were Methicillin-resistant Staphylococcus aureus (MRSA), 23 (41%) were Methicillin-resistant coagulase-negative Staphylococcus (MR-CONS). Of the isolates, 8 (14%) were Methicillin sensitive Staphylococcus aureus (MSSA). None of the MR-CoNS and S. aureus strains was resistant to vancomycin.&#x0D; Conclusion: Gram-negative bacilli outnumbered Gram-positive organisms in adult septicaemic patients. The majority of these organisms were multidrug-resistant, necessitating the need for timely culture and adjusting antimicrobials according to susceptibility profile.

Comparative microbial analysis and assessment of paired umbilical cord blood culture and peripheral venous blood culture in neonates with high risk factors to detect early onset neonatal sepsis: A study from tertiary care hospital of central India

Background: Neonatal sepsis is a prime cause of neonatal morbidity and mortality. Peripheral venous blood (PVB) culture is a gold standard for the diagnosis of neonatal sepsis. Low sensitivity of blood culture in newborn is due to small volume of blood sample and antibiotics given before sampling. Aims and Objectives: The study aims to compare and analyze the microbial spectrum in the Umbilical cord blood (UCB) culture with PVB culture and evaluation of both for detection of early onset neonatal sepsis (EONS) in high risk neonates and to use appropriate microorganism specific antibiotic for treating the sepsis. Materials and Methods: About 100 inborn neonates with two or more risk factors for EONS, chosen by sequential sampling method were included in this prospective analytical study. Blood samples were collected from umbilical cord and peripheral vein for culture. Sepsis screen was done to substantiate the diagnosis of neonatal sepsis. Results: Out of 100 neonates, 21 belongs to sepsis; 14 to probable sepsis; 65 to no sepsis. Among these 27 had UCB culture &amp; 24 had PVB culture +ve. Organisms grown on culture were Klebsiella(m/c isolate), Staphylococcus aureus, Escherichia coli, Acinetobacter, Coagulase-ve Staphylococcus (blood culture contaminant), Pseudomonas and Enterococcus. Conclusion: UCB culture is simple and convenient method for the diagnosis of neonatal sepsis as compared to PVB culture with Sensitivity of 66% and specificity of 93%. Organisms grown are comparable to PVB culture sample (Klebsiella - most common isolate).