Anaerobic Blood Culture Research Articles

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.

Utility of Anaerobic Blood Cultures in Neonatal Sepsis Evaluation.

Clinicians variably obtain anaerobic blood cultures as part of sepsis evaluations in the neonatal intensive care unit (NICU). Our objective was to determine if anaerobic blood culture bottles yielded clinically relevant information by either recovering pathogens exclusively or more rapidly than the concurrently obtained aerobic culture bottle in the NICU. A retrospective cohort study of blood cultures obtained from infants admitted to the NICU from August 01, 2015 to August 31, 2023. Standard practice was to inoculate 2 mL of blood divided equally between an aerobic and an anaerobic culture bottle. We analyzed positive blood cultures where both aerobic and anaerobic bottles were obtained and compared pathogen recovery and time to positivity between the bottles. During the study period, 4599 blood cultures were obtained from 3665 infants, and 265 (5.8%) were positive. Of these, 182 cultures were sent as aerobic-anaerobic pairs and recovered pathogenic organisms. Organisms were recovered exclusively from the anaerobic bottle in 32 (17.6%) cultures. Three organisms were obligate anaerobes; the rest were facultative anaerobes including Coagulase-negative staphylococci (40.6%), Escherichia coli (15.6%), and Staphylococcus aureus (15.6%). Cultures with exclusive recovery in the anaerobic bottle were more frequently obtained ≤3 days after birth, compared to other cultures (31.3% vs 15.3%, P = .03). When both bottles recovered the pathogen (n = 113), the anaerobic bottle had a shorter time to positivity in 76 (67.3%) cultures. Including anaerobic culture bottles could lead to the identification of pathogens not recovered in the aerobic bottle, as well as earlier identification of pathogens.

172. Impact of a quality improvement re-training program on the blood culture volume, yield and contamination rates; experience from South India

Abstract Background Blood cultures help to detect causative agents in bacteremia and are important for targeted therapy. Adequate blood culture volume is considered as 8-10ml in each bottle and at least 2 aerobic and 2 anaerobic blood culture bottles are recommended. Inadequate blood culture fills are common and may affect yield. Figure 1 Methods The study was done in our healthcare facility-KIMSHEALTH, Trivandrum, India. Pre-intervention period was between May 2021 and June 2021; post-intervention was between May 2022 and June 2022. The intervention was through plan/do/study/act (PDSA) cycles and included multiple training sessions to the phlebotomy team regarding adequate fill volume which is 8-10 ml in each blood culture bottle. Training for maintaining asepsis during collection was reinforced. All blood culture samples received in the hospital microbiology laboratory during the above period were included in this study and compared between the pre-intervention and post-intervention period. Pediatric blood culture samples were excluded. Results Blood culture samples studied during pre and post intervention period were 1428 and 1716 respectively. In the pre-intervention phase adequate fill volume was noted in 30.81% bottles (figure 1), while in the post intervention adequate fill volume was noted in 68.06% bottles (p < 0.01). Blood culture contamination rate was 3.01% in the pre-intervention period which improved to 2% in the post-intervention period and the difference was significant (p< 0.01). Blood culture yield of a pathogenic organism did not show significant difference after the intervention (11.2% in pre-intervention group Vs 11.45% in post intervention group). Conclusion In this study, an improvement was noted in the blood culture fills by 38% and contamination rate reduced by 1%. Though there was no significant increase in blood culture yield with intervention, the reduction in contamination was noted which will reduce unnecessary antibiotic initiation. Disclosures All Authors: No reported disclosures

587. Research and Development of Image Recognition AI to Estimate Bacterial Species using Gram Stain Findings in Aerobic and Anaerobic Blood Culture Bottle

Abstract Background Background In the highly fatal infectious disease of bacteremia, the ability to select antimicrobial agents at an earlier time is critical not only for early patient recovery, but also for reducing the development of resistant organisms. Gram staining of blood cultures is a useful test for early selection of antimicrobial agents, but it requires some skill in deciphering. Therefore, we developed an image analysis system for Gram stain images of blood cultures and have verified whether it is possible to estimate the bacterial species to facilitate the initial selection of antimicrobial agents, regardless of the level of proficiency. Methods Method Slides and bacterial species-identification information from an anonymized Gram stain registry at two medical institutions, National Center for Global health and Medicine (NCGM) and Kobe University Hospital (KUH), were used for the study. 1113 cases of aerobic bottles and 1060 cases of anaerobic bottles were included. Mock-specimens were used for the rare bacteria. A total of 23,947 images were generated by capturing the observation field of view of an optical microscope with a smartphone. Table 1 shows the bacterial classification of aerobic bottles and Table 2 shows the bacterial classification of anaerobic bottles. The data were divided into training data and test data at a ratio of 8 to 2 for each category.Table 1.A total of 16 categories of bacteria were used for classification of aerobic bottlesTable 2.A total of 16 categories of bacteria were used for classification of anaerobic bottles Results The macro-average recall (sensitivity) and accuracy of the test data were 64% and 82% for aerobic bottles and 68% and 86% for anaerobic bottles, respectively. The results showed the possibility of classifying the performing bacterial species with an accuracy of over 70% using only Gram stained images via image recognition AI. For aerobic bottles in particular, the seven categories of GNR, GNC, GPR, GPC, yeast, No organism, and multiple bacteria are predicted to have 97% accuracy, and 90% macro average recall. Conclusion The research has shown that it is possible to classify bacterial species to a certain extent only by observing the Gram stain images. Our goal is to narrow down and focus more on the clinically-meaningful bacterial species, and to improve the accuracy of our classification. Also, we are planning to make comparisons with specialists in the future. Disclosures Kei Yamamoto, MD, Canon medical systems: Grant/Research Support|CarbGeM: Grant/Research Support|CarbGeM: 7090302|Fujirebio: Grant/Research Support|Sanyo Chemical Industries: Grant/Research Support|VisGene: Grant/Research Support Goh Ohji, MD, PhD, DTMH, CarbGeM: Advisor/Consultant

Clinical usefulness of anaerobic blood culture in pediatric patients with bacteremia

ObjectivesThe purpose of this study is to evaluate the usefulness of anaerobic blood culture in pediatric patients by comparing the detection rate and distribution of bacteria between aerobic and anaerobic blood culture bottles. MethodsA retrospective analysis was conducted on 11,664 blood cultures obtained from children under the age of 14 between January 2013 and June 2020. The positive rate of total, aerobic, and anaerobic blood culture, as well as the species distribution of each blood culture bottle, were investigated. ResultsThe positive rate of blood culture was 2.4 % (N = 281). Among them, 67 (23.8 %), 85 (30.3 %) and 129 (45.9 %) organisms were grown in only aerobic, only anaerobic, and both blood culture bottles, respectively. Gram-positive cocci were cultured on both, only aerobic, and only anaerobic blood culture bottles in proportions of 46.4 %, 23.4 %, and 30.2 %, respectively. Gram-negative bacilli were cultured on both, only aerobic, and only anaerobic blood culture bottles in proportions of 58.5 %, 12,3 %, and 29.2 %, respectively. Gram-positive bacilli grew best in aerobic bottle only. There were seven strains of obligate anaerobes. ConclusionBecause many facultative anaerobic bacteria are recognized primarily from anaerobic blood culture bottles, combining aerobic and anaerobic blood culture bottles might be beneficial in pediatric patients with suspected blood stream infection.

Validation of the Accuracy of Automatic Measurement of Blood Volume in Culture Bottles for Blood Culture.

Several manufacturers have developed systems that automatically measure the amount of blood in culture bottles. We compared the volumes measured automatically by the Virtuo instrument (bioMérieux, France) (height-based volumes) and those calculated by weighing the bottles. In all, 150 pairs of aerobic and anaerobic blood culture bottles (BacT/ALERT FA/FN Plus, bioMérieux) were randomly selected over two periods to compare the height- and weight-based volumes and analyze the effect of foam. We also estimated the limit of detection (LOD) and the cut-off value for 5 mL equine blood. The mean height-based volume was approximately 0.67 mL greater than the weight-based volume, particularly in anaerobic culture bottles. Foam did not have a significant effect. The LOD for the automatic height-based volume of equine blood was 0.2-0.4 mL. The 5 mL cut-off was 4-4.2 mL. Therefore, when reporting or monitoring blood volume within culture bottles in the laboratory, these performance characteristics should be adequately considered.

Vertebral osteomyelitis caused by Fusobacterium nucleatum with an associated asymptomatic liver abscess in an immunocompetent adult: A case report and literature review

Fusobacterium nucleatum rarely causes vertebral osteomyelitis or liver abscesses, and no reports exist of it concurrently causing vertebral osteomyelitis and pyogenic liver abscess. A 58-year-old woman with a history of periodontitis presented with worsening lumbago, left lower leg pain, numbness, and fever for a week. Physical examination indicated knocking pain at the L2-L3 levels with a psoas sign on the left side. A magnetic resonance image showed L2-S1 vertebral osteomyelitis and intervertebral discitis, with a left psoas major muscle abscess. Vertebral osteomyelitis caused by Staphylococcus aureus was suspected; blood cultures were obtained, and intravenous cefazolin was administered. Computed tomography, which was performed to detect disseminated foci, revealed a multilocular liver abscess. On day 4 of incubation, the anaerobic blood culture bottles were positive for characteristic filamentous gram-negative rods. The empiric antimicrobial therapy was changed to ampicillin/sulbactam. The isolate was identified as F. nucleatum based on 16S rRNA gene sequencing. The liver abscess was drained on day 12. Based on the antimicrobial susceptibility test results, the patient was treated with intravenous ampicillin/sulbactam for 4 weeks followed by oral amoxicillin/clavulanate for an additional 8 weeks and remained disease-free at the 1-year follow-up. Clinicians should consider F. nucleatum as the causative organism for vertebral osteomyelitis presenting with asymptomatic pyogenic liver abscess. The gold standard for identifying and diagnosing F. nucleatum infections is 16S rRNA gene sequencing, and gram staining helps determine appropriate antimicrobials.

A case report of Gemella sanguinis isolated from blood cultures of a patient with mitral valve prolapse

Gemella sanguinis is a gram-positive, facultatively anaerobic coccus bacterium that has rarely been reported as a cause of infective endocarditis. A 41-year-old male patient with mitral valve prolapse visited the outpatient clinic presenting with fever. Transthoracic echocardiography and transesophageal echocardiography revealed myxomatous change and vegetation of the mitral valve. We isolated G. sanguinis from the patient’s blood, cultured it in both aerobic and anaerobic blood culture bottles, and identified it using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS; bioMérieux, France) and 16s rRNA sequencing. The isolated G. sanguinis was highly susceptible to penicillin and vancomycin and intermediately susceptible to erythromycin, clindamycin, and levofloxacin. Following the American Heart Association recommendations, this highly penicillin-sensitive isolate was eradicated with ceftriaxone and gentamicin, and the patient recovered and was discharged. To the best of our knowledge, this is the first reported case in Korea where G. sanguinis, the causative agent of endocarditis, was identified using MALDI-TOF MS and 16s rRNA sequencing and was treated with only antibiotics and without surgical valve replacement.

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.

Epidemiology and outcome of anaerobic bacteremia in a tertiary hospital

Despite a low incidence, anaerobic bacteremia remains a serious and often underestimated condition. This retrospective study aims to describe the epidemiology of anaerobic bacteremia and to identify risk factors affecting mortality and the impact of treatment. We included all positive anaerobic blood cultures from January 2018 to December 2019 at the University Hospital of Charleroi (Belgium). We identified 105 episodes of clinically significant anaerobic bacteremia (mean age of patients: 66.4 +/- 16.8 years). The main comorbidities were hypertension, chronic kidney disease, and diabetes. Bacteremia was community-acquired in 70.5% of the episodes. Two thirds of the blood cultures were mono-microbial, and the commonest bacteria found were Bacteroides fragilis group (31.4%), Fusobacterium spp. (17.1%) and Clostridium spp. (15.2%). The main sources of bacteremia were abdominal (35.2%), urinary (17.1%), osteoarticular (14.2%) and pulmonary (12.3%). Surgery within 30 days before hospitalization was more frequent in patients with nosocomial bacteremia (45.2% vs 2.7%, p < 0.0001). An appropriate empirical antibiotic therapy was initiated in 74.7% of patients, and the median duration of antibiotic therapy was 10 [5 - 15] days. One third of patients had a surgical management. Patients who did not survive at day 30 (n = 23 [21.9%]) had significantly lower time to positivity (TTP) values than patients alive at day 30, presented more often with sepsis, had higher Charlson scores and chronic kidney disease, and were more likely to suffer from Clostridium spp. bacteremia. In a Cox proportional hazard analysis, sepsis (OR: 7.32 [95% CI: 2.83– 18.97], p< 0.0001) was identified as an independent risk factors for 30-day mortality, whereas time to positivity ≥ 30 h (OR: 0.24 [95% CI: 0.07 – 0.84], p = 0.025) and an adequate empirical antibiotic therapy (OR: 0.37 [95% CI: 0.15 – 0.94], p = 0.037) were associated with better outcomes. Anaerobic bacteremia has a high mortality rate which justifies the maintenance of empirical antibiotic therapy.

Routine Use of Anaerobic Blood Culture Bottles for Specimens Collected from Adults and Children Enhances Microorganism Recovery and Improves Time to Positivity.

The utility of anaerobic blood culture bottles remains controversial, especially for specimens from children. Data are limited on the inclusion of an anaerobic bottle as part of a blood culture "set" when using contemporary blood culture instruments and media. Here, we evaluated the clinical utility of anaerobic blood culture bottles (FN Plus) and aerobic bottles (FA Plus) for the BacT/Alert Virtuo blood culture system (bioMérieux). A total of 158,710 bottles collected between November 2018 and October 2019 were evaluated. There were 6,652 positive anaerobic bottles, of which 384 (5.8%) contained 403 obligate anaerobes. In patients <19 years old, there were 389 positive anaerobic bottles, with 15 (1.8%) containing 16 obligate anaerobes. If not for anaerobic bottles, all but 8 obligate anaerobes would have gone undetected. Furthermore, anaerobic bottles were advantageous for some facultative anaerobes. Staphylococcus aureus from anaerobic bottles demonstrated statistically significant increased recovery (1,992 anaerobic versus 1,901 aerobic bottles, P = 0.009) and faster mean time to positivity (1,138 versus 1,174 min, P = 0.027). Only 25 microorganisms had statistically significant improved recovery and/or faster time to positivity from aerobic versus anaerobic bottles, suggesting anaerobic bottles offer comparable growth for most species. Finally, if only an aerobic bottle had been collected, 2,027 fewer positive cultures would have been detected and 7,452 fewer isolates would have been reported, including cultures with S. aureus (413 isolates, 10.6% less), Pseudomonas aeruginosa (9 isolates, 3.1% less) and Escherichia coli (193 isolates, 14.0% less). Taken together, these findings support the practice of routinely including an anaerobic bottle for blood culture collection.

Blood Culture Headspace Gas Analysis Enables Early Detection of Escherichia coli Bacteremia in an Animal Model of Sepsis.

(1) Background: Automated blood culture headspace analysis for the detection of volatile organic compounds of microbial origin (mVOC) could be a non-invasive method for bedside rapid pathogen identification. We investigated whether analyzing the gaseous headspace of blood culture (BC) bottles through gas chromatography-ion mobility spectrometry (GC-IMS) enables differentiation of infected and non-infected; (2) Methods: BC were gained out of a rabbit model, with sepsis induced by intravenous administration of E. coli (EC group; n = 6) and control group (n = 6) receiving sterile LB medium intravenously. After 10 h, a pair of blood cultures was obtained and incubated for 36 h. The headspace from aerobic and anaerobic BC was sampled every two hours using an autosampler and analyzed using a GC-IMS device. MALDI-TOF MS was performed to confirm or exclude microbial growth in BCs; (3) Results: Signal intensities (SI) of 113 mVOC peak regions were statistically analyzed. In 24 regions, the SI trends differed between the groups and were considered to be useful for differentiation. The principal component analysis showed differentiation between EC and control group after 6 h, with 62.2% of the data variance described by the principal components 1 and 2. Single peak regions, for example peak region P_15, show significant SI differences after 6 h in the anaerobic environment (p < 0.001) and after 8 h in the aerobic environment (p < 0.001); (4) Conclusions: The results are promising and warrant further evaluation in studies with an extended microbial panel and indications concerning its transferability to human samples.

Identification of Peptoniphilus vaginalis-Like Bacteria, Peptoniphilus septimus sp. nov., From Blood Cultures in a Cervical Cancer Patient Receiving Chemotherapy: Case and Implications

A 39-year-old woman with a 3-year human papillomavirus (HPV) 18 infection history was admitted to the hospital for a 16-day history of vaginal bleeding after sex. She was diagnosed with cervical cancer based on the results of the electronic colposcopy, cervical cytology, microscopy, and magnetic resonance imaging (MRI). Then, she received chemotherapy, with paclitaxel 200 mg (day 1), cisplatin 75 mg (day 2), and bevacizumab 700 mg (day 3) twice with an interval of 27 days. During the examination for the diagnosis and treatment, many invasive operations, including removal of intrauterine device, colposcopy, and ureteral dilatation, were done. After that, the patient was discharged and entered the emergency department about 2.5 months later with a loss of consciousness probably caused by septic shock. The patient finally died of multiple organ failure and bacterial infection, although she has received antimicrobial therapy. The blood cultures showed a monobacterial infection with an anaerobic Gram-positive bacterial strain, designated as SAHP1. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI–TOF MS) indicated that the patient was infected with Peptoniphilus asaccharolyticus, while molecular analysis and genome-based taxonomy confirmed the infection with a novel Peptoniphilus species that has a close genetic relationship with Peptoniphilus vaginalis and proposed provisionally as Peptoniphilus septimus sp. nov., which may also act as a commensal of the human vagina. Genomic features of SAHP1 have been fully described, and comparative genomic analysis reveals the known prokaryote relative of Peptoniphilus septimus sp. nov. in the genus Peptoniphilus. The invasive operations on the genital tract during the diagnosis and treatment of the patient and the tumor tissue damage and bleeding may have a certain role in the bloodstream infection. This study casts a new light on the Peptoniphilus bacteria and prompts clinicians to include anaerobic blood cultures as part of their blood culture procedures, especially on patients with genital tract tumors. Furthermore, due to the incomplete database and unsatisfying resolution of the MALDI–TOF MS for Peptoniphilus species identification, molecular identification, especially whole-genome sequencing, is required for those initially identified as bacteria belonging to Peptoniphilus in the clinical laboratory.

Alteration of the Inflammatory and Anti-Inflammatory Cytokine Profiles of Peripheral Blood Mononuclear Cell in Crohn's Disease Patients after Following up.

Background:Crohn’s disease (CD) has a chronic course, which its recurrence varies widely among different patients. In this study we prospectively analyzed blood samples of 19 CD patients. Alteration in transcription of inflammatory and anti-inflammatory cytokines was analyzed compared with household members after three month follow up.Methods:CD patients were diagnosed based on clinical symptoms, endoscopic and histopathologic characteristics. Nineteen CD patients and their households were evaluated from Jun 2019 to Feb 2021 at Tehran university hospitals. CD activity score, biological, clinical and demographic data of the patients were recorded at two time point intervals. Bacteriological tests were done using aerobic and anaerobic blood cultures. To investigate transcriptional alterations, peripheral blood mononuclear cells (PBMCs) were isolated using Ficol centrifugation method and relative quantitative real-time PCR was done to determine the expression level of IFN-γ, TNF-α, IL10, and FOXP3 cytokines.Results:Our results showed a correlation between fecal calprotectin level (709.8 ± 554.6), C-reactive protein concentration (18.1 ± 15.9), and erythrocyte sedimentation rate (30.4 ± 17.9) with disease activity (Flare/remission). IL10 and Foxp3 anti-inflammatory gene’s expression were significantly (P = 0.003 for IL10 and P = 0.008 Foxp3) higher during the flare and remission in patients with active disease respectively. Bacteriological examination showed infection with Streptococcus spp. and Clostridium spp. in two CD patients during flares, which was correlated with upregulation and down-regulation of IL10, TNF-α, IFN-γ and FOXP3 proteins, respectively.Conclusion:Occurrence of bacteremia, and higher amount of CAP, CRP and ESR are correlated with higher level of transcription for inflammatory cytokines, which could effectively reflect the disease activity. Raise in FoxP3 transcription proposed change in Treg sub-population in PBMC or its activity during the CD remission phase.

Little Utility of Fungal Blood Cultures in Surgical and Burn Intensive Care Units.

ABSTRACTCritically ill patients are at risk for fungal infections, but there is a paucity of data regarding the clinical utility of dedicated fungal blood cultures to detect such infections. A retrospective review was conducted of patients admitted to the surgical and burn intensive care units at Parkland Memorial Hospital between 1 January 2013 and 31 December 2017 for whom blood cultures (aerobic, anaerobic, and/or fungal cultures) were sent. A total of 1,094 aerobic and anaerobic blood culture sets and 523 fungal blood cultures were sent. Of the aerobic and anaerobic culture sets, 42/1,094 (3.8%) were positive for fungal growth. All fungal species cultured were Candida. Of the fungal blood cultures, 4/523 (0.76%) were positive for growth. Fungal species isolated included Candida albicans, Aspergillus fumigatus, and Histoplasma capsulatum. All 4 patients with positive fungal blood cultures were on empirical antifungal therapy prior to results, and the antifungal regimen was changed for 1 patient based on culture data. The average duration to final fungal culture result was 46 days, while the time to preliminary results varied dramatically. Two of the four patients died prior to fungal culture results, thereby rendering the culture data inconsequential in patient care decisions. This study demonstrates that regular aerobic and anaerobic blood cultures sets are sufficient in detecting the most common causes of fungemia and that results from fungal cultures rarely impact treatment management decisions in patients in surgical and burn intensive care units. There is little clinical utility to routine fungal cultures in this patient population.IMPORTANCE This study demonstrates that regular aerobic and anaerobic blood culture sets are sufficient in detecting the most common causes of fungemia, and thus, sending fungal blood cultures for patients in surgical and burn intensive care units is not a good use of resources.

Evaluation of an extracorporeal ozone-based bactericide system for the treatment of Escherichia coli sepsis

BackgroundSepsis is associated with substantial mortality rates. Antibiotic treatment is crucial, but global antibiotic resistance is now classified as one of the top ten global public health risks facing humanity. Ozone (O3) is an inorganic molecule with no evident function in the body. We investigated the bactericide properties of ozone, using a novel system of extracorporeal ozone blood treatment. We hypothesized that ozone would decrease the concentration of viable Escherichia coli (E. coli) in human whole blood and that the system would be technically feasible and physiologically tolerable in a clinically relevant model of E. coli sepsis in swine.MethodsThe E. coli strain B09-11822, a clinical isolate from a patient with septic shock was used. The in vitro study treated E. coli infected human whole blood (n = 6) with ozone. The in vivo 3.5-h sepsis model randomized swine to E. coli infusion and ozone treatment (n = 5) or E. coli infusion and no ozone treatment (n = 5). Live E. coli, 5 × 107 colony-forming units (CFU/mL) was infused in a peripheral vein. Ozone treatment was initiated with a duration of 30 min after 1.5 h.ResultsThe single pass in vitro treatment decreased E. coli by 27%, mean 1941 to 1422 CFU/mL, mean of differences − 519.0 (95% CI − 955.0 to − 82.98, P = 0.0281). pO2 increased (95% CI 31.35 to 48.80, P = 0.0007), pCO2 decreased (95% CI − 3.203 to − 1.134, P = 0.0069), oxyhemoglobin increased (95% CI 1.010 to 3.669, P = 0.0113). Methemoglobin was not affected. In the sepsis model, 9/10 swine survived. One swine randomized to ozone treatment died from septic shock before initiation of the treatment. Circulatory, respiratory, and metabolic parameters were not affected by the ozone treatment. E. coli in arterial blood, in organs and in aerobic and anaerobic blood cultures did not differ. Hemoglobin, leucocytes, and methemoglobin were not affected by the treatment.ConclusionsOzone decreased the concentration of viable E. coli in human whole blood. The system was technically feasible and physiologically tolerable in porcine sepsis/septic shock and should be considered for further studies towards clinical applications.

Contribution of the anaerobic blood culture vial for the recovery of Candida glabrata: A retrospective multicentric study.

Although Candida spp are aerobic microorganisms, C. glabrata is able to grow in anaerobic conditions. In blood culture, the time-to-positivity of C. glabrata is shorter in anaerobic than aerobic vials. Only the anaerobic vial was positive in up to 15 (37.5%) C. glabrata bloodstream infections.

An Improvement in Diagnostic Blood Culture Conditions Allows for the Rapid Detection and Isolation of the Slow Growing Pathogen Yersinia pestis.

Plague, caused by the human pathogen Yersinia pestis, is a severe and rapidly progressing lethal disease that has caused millions of deaths globally throughout human history and still presents a significant public health concern, mainly in developing countries. Owing to the possibility of its malicious use as a bio-threat agent, Y. pestis is classified as a tier-1 select agent. The prompt administration of an effective antimicrobial therapy, essential for a favorable patient prognosis, requires early pathogen detection, identification and isolation. Although the disease rapidly progresses and the pathogen replicates at high rates within the host, Y. pestis exhibits a slow growth in vitro under routinely employed clinical culturing conditions, complicating the diagnosis and isolation. In the current study, the in vitro bacterial growth in blood cultures was accelerated by the addition of nutritional supplements. We report the ability of calcium (Ca+2)- and iron (Fe+2)-enriched aerobic blood culture media to expedite the growth of various virulent Y. pestis strains. Using a supplemented blood culture, a shortening of the doubling time from ~110 min to ~45 min could be achieved, resulting in increase of 5 order of magnitude in the bacterial loads within 24 h of incubation, consequently allowing the rapid detection and isolation of the slow growing Y. pestis bacteria. In addition, the aerobic and anaerobic blood culture bottles used in clinical set-up were compared for a Y. pestis culture in the presence of Ca+2 and Fe+2. The comparison established the superiority of the supplemented aerobic cultures for an early detection and achieved a significant increase in the yields of the pathogen. In line with the accelerated bacterial growth rates, the specific diagnostic markers F1 and LcrV (V) antigens could be directly detected significantly earlier. Downstream identification employing MALDI-TOF and immunofluorescence assays were performed directly from the inoculated supplemented blood culture, resulting in an increased sensitivity and without any detectable compromise of the accuracy of the antibiotic susceptibility testing (E-test), critical for subsequent successful therapeutic interventions.

Bacteremia due to obligate anaerobes following large bowel surgery in a tertiary care hospital in South India

In view of the rising incidence of Anaerobic bacteremia(AB), the use of anaerobic blood culture bottles have been recommended in addition to the aerobic blood culture bottles. The need to perform antimicrobial susceptibility testing(AST) for anaerobes has become mandatory owing to increasing metronidazole resistance. The frequency of AB following large bowel surgery and the metronidazole susceptibility for members of the Bacteroides fragilis group were determined. The incidence of AB was found to be 16%. Seventeen obligate anaerobes were isolated in total, of which B. fragilis was the most common. Two of twelve isolates of B. fragilis were resistant to metronidazole.

Role of Clostridium Perfringens in Neonatal Necrotizing Enterocolitis and the Utility of Anaerobic Blood Cultures

Introduction: Clostridium perfringens is a gram-positive anaerobic bacillus that causes various clinical diseases, including necrotizing enterocolitis in newborns. The progression could be fulminant and lethal. Presentation of the cases: We report 3 cases of necrotizing enterocolitis due to C. perfringens from 2 high-complexity public centers in Chile. Conclusion: Strong clinical suspicion combined with early microbiological identification may modify patient evolution. Anaerobic blood cultures have become a fundamental diagnostic method; therefore, having this tool in neonatal units would be useful