Blood Culture System 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.

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.

Incidence, antimicrobial susceptibility & out of pocket expenditure of severe enteric fever in Chandigarh, north India.

Background & objectives Burden estimates of enteric fever are required to make policy decisions on introducing typhoid vaccine in India. Incidence, antimicrobial susceptibility, and out-of-pocket expenditure (OOPE) of enteric fever are estimated in Chandigarh, India. Methods A hybrid (facility and community-based) surveillance system was set up at a secondary care hospital to enrol patients above six months of age, hospitalized with fever, from a defined catchment population from May 2018 to March 2020. Blood samples were collected and cultured using an automated system (BD BACTECTM blood culture system). The Salmonella Typhi and S. Paratyphi isolates were characterized for antimicrobial susceptibility. OOPE was recorded after 14 and 28 days of discharge. Results Blood samples were collected from 97 per cent of the 1650 study participants enrolled. The incidence of enteric fever was 226.8 per 1,00,000 person-years (PY), severe typhoid fever 156.9 per 1,00,000 PY, and severe paratyphoid fever 69.9 per 1,00,000 PY. Salmonella was highly susceptible to ampicillin, azithromycin, and ceftriaxone (99.25%) and least susceptible to ciprofloxacin (11.3%). The OOPE due to hospitalization of individuals infected with S. Paratyphi [INR 8696.6 (USD 116)] was significantly higher than the individuals infected with S. Typhi [INR 7309 (USD 97.5), P=0.01], and among cases who were hospitalized for more than seven days [INR 12,251 (USD 163.3)] as compared with those with a stay of 3-7 days [INR 8038.2 (USD 107.2)] or less than three days [INR 5327.8 (USD 71), P<0.001]. Interpretation & conclusions There was a high incidence of enteric fever, high OOPE, and resistance to ciprofloxacin.

Exploring the antimicrobial efficacy of Manuka honey against multidrug-resistant and extensively drug-resistant Salmonella Typhi causing septicemia in Pakistan.

Aim: To determine the efficacy of manuka honey against multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical strains of Salmonella Typhi.Materials & methods: Clinical isolates were processed using the Bactec blood culture system, identificationand antibiogram by Vitek 2and antibiotic resistance genes through polymerase chain reaction (PCR). Microbroth dilution assays evaluated the antibacterial activity of manuka honey.Results: MDR and XDR-S. Typhi was susceptible to azithromycin. These strains carried the H58, gyrA, gyrB, blaCTX-M-15, and blaTEM-1 genes. At 100% honey, the zone of inhibition for MDR (15-23mm) and XDR (15-24mm) strains. 18/50 MDR and 14/50 XDR strains inhibited at 3.125v/v% killed at 6.25v/v% concentration respectively.Conclusion: Manuka honey could be an alternative option for treating S. Typhi infections.

Estimating bacterial load in S. aureus and E. coli bacteremia using bacterial growth graph from the continuous monitoring blood culture system

BackgroundWe examined whether the time to positivity (TTP) and growth and detection plot graph (GDPG) created by the automated blood culture system can be used to determine the bacterial load in bacteremic patients and its potential association correlation with disease severity.MethodsKnown bacterial inocula were injected into the blood culture bottles. The GDPGs for the specific inocula were downloaded and plotted. A cohort of 30 consecutive clinical cultures positive for S. aureus and E. coli was identified. Bacterial load was determined by comparing the GDPG with the “standard” curves. Variables associated with disease severity were compared across 3 bacterial load categories (< 100, 100–1000, > 1000 CFU/mL).ResultsS. aureus growth was sensitive to the blood volume obtained whereas E. coli growth was less so. A 12-hour delay in sample transfer to the microbiology laboratory resulted in a decrease in TTP by 2–3 h. Mean TTP was 15 and 10 h for S. aureus and E. coli, respectively, which correlates with > 1000 CFU/mL and 500–1000 CFU/ml. For S. aureus, patients with a bacterial load > 100 CFU/mL had a higher mortality rate, (OR for death = 9.7, 95% CI 1.6–59, p = 0.01). Bacterial load > 1000 CFU/mL had an odds ratio of 6.4 (95% CI1.2-35, p = 0.03) to predict an endovascular source. For E. coli bacteremia, we did not find any correlations with disease severity.ConclusionGDPG retrieved from the automated blood culture system can be used to estimate bacterial load. S.aureus bacterial load, but not E.coli, was associated with clinical outcome.

Evaluation of BACTEC™ FX and BacT/Alert™ Automated Blood Culture Systems for Detection of Clinically Relevant Bacterial and Yeast Species

Background: Bloodstream infections (BSI) are a significant health concern, necessitating effective diagnostic tools. This study evaluates the performance of the BD Bactec FX system in comparison to the established BacT/Alert system, examining mean time till detection (TTD) across various blood culture bottles.Methods: The study involves 148 blood culture bottles, inoculated with representative bacterial ATCC strains (n= 15) and 04 yeast isolates. Parallel testing is conducted by seeding 10–30 colony-forming units (CFU) in duplicate in both BD Bactec FX and BacT/Alert systems. TTD is assessed across aerobic, anaerobic, and pediatric bottles for diverse microbial species.Results: All 148 bottles tested in parallel show positive signals in both systems. BD Bactec FX demonstrates significantly shorter TTD for adult-seeded cultures in aerobic and anaerobic bottles compared to BacT/Alert Similarly, pediatric bottles with BD Bactec FX exhibit a shorter TTD compared to BacT/Alert. The statistical significance of TTD, 95% confidence intervals (CI), and p-values is evident for Bactec FX aerobic, anaerobic, and pediatric bottles across tested organisms. Notable examples of faster TTD include; Bacteroides ovatus (16.6h by Bactec FX vs. 70.5h by Bact/Alert 3D), Stenotrophomonas maltophilia (33.7h vs. 72.5h), and Streptococcus pyogenes (8.1h vs. 11.9h).Conclusions: In conclusion, the study’s findings demonstrate that BD Bactec FX surpasses BacT/Alert in prompt microbial detection, showcasing potential for early identification of bacteremia and fungemia. Faster TTD implies the potential to initiate timely antimicrobial treatment, thereby reducing patient morbidity and mortality. However, exceptions in certain microbial species highlight the need for comprehensive clinical validation to establish the broad applicability of these findings.Keywords: Blood Culture System; Recovery Rate; Time to detection; Blood stream infection; BTA3D; Bactec FX

Clinical Findings, Bacterial Agents, and Antibiotic Resistance in Children with Spontaneous Peritonitis in Southern Iran: An Academic Tertiary Referral Center's Experience.

Spontaneous bacterial peritonitis (SBP) is a fatal complication of ascites fluid infection. The causes of SBP in children differ from those in adults, and these bacteria are frequently resistant to antibiotics. Therefore, this study investigated the clinical findings, bacterial etiology, and antimicrobial resistance in children with SBP. This study was conducted on all new pediatric ascites patients, who were admitted to the Department of Pediatric Gastroenterology, Namazi Hospital, affiliated with Shiraz University of Medical Sciences (Shiraz, Iran) from 2021 to 2022. Required data such as demographic information, and clinical information such as complete blood count (CBC), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Gram staining, blood culture by Automated Blood Culture System (BACTEC), and antibiogram of ascites fluids by disc diffusion method were all collected. Finally, the data were statistically analyzed using SPSS Software (version 26). Besides, the t test, Fisher's exact, Mann-Whitney, and Chi square tests were used for data analysis. In all tests, P≤0.05 was considered statistically significant. The present study examined 62 children with ascites of which 18 (29%) had SBP. The median (IQR) age was 2.5 (8.1) years. Thirty-four (54.8%) of the participants were girls. Abdominal pain was the most common clinical manifestation in patients (54%), and there was a significant association between abdominal pain and SBP (P=0.02). In 12 positive ascites fluid cultures, coagulase-negative staphylococci had the highest frequency (25%), followed by Escherichia coli (16.7%). Third-generation cephalosporins had a 25% sensitivity in the total positive cultures. This sensitivity was 33.3% for Gram-negative cultures and 16.6% for Gram-positive cultures. Although third-generation cephalosporins are recommended as the primary antibiotic for the empirical treatment of SBP, the present study found high bacterial resistance. Finally, empirical therapy should be tailored to each region's bacterial resistance features.

Use of flow cytometry method to detect contaminations of platelet suspensions

In this study, it was aimed to investigate bacterial contamination in apheresis platelet suspensions (APS) by automated blood culture system and flow cytometry method (FCM).33 spiked APS each using 11 bacterial strains (5 standard strains, 6 clinical isolates), were prepared in three different dilutions (1–10, 10–50, 50-100 cfu/mL), incubated in two different temperatures (35–37 °C and 22–24 °C) and different incubation times (18–96 h) evaluated by FCM. This three different dilutions were also inoculated into special platelet culture bottles (BacT/ALERT® BPA) and loaded into the blood culture system. Additionally 80 APSs routinely prepared in the Transfusion Center were evaluated by both FCM and the blood culture system. Platelets were lysed by freeze-thaw method.All spiked samples were positive with BacT/ALERT® BPA in 12–18 h. In 96 h incubation at 22–24 °C, the presence of bacteria was detected by FCM in all other samples (31/33) except low dilutions (1–10 and 10–100 CFU/ml) of K.pneumoniae standard strain. In the 35–37 °C, the presence of bacteria was detected by FCM in all samples (33/33) after 48 h of incubation. In routine APS one sample detected as positive (Bacillus simplex) with BacT/ALERT® BPA and no positivity was detected by FCM.The freeze-thaw method, which we have optimized for the lysis of platelets, is very practical and can be easily applied. The BacT/ALERT® system has been found to be very sensitive in detecting bacterial contamination in PSs. Flow cytometry method has been found to be successful, fast, easy to use and low cost in detecting bacterial contamination in PSs.

Assessment of Adequate Blood Culture Incubation Time to Accentuate Clinically Relevant Results from Blood Culture Instrument and Media System in a Tertiary Care Hospital Lahore

Background: Bloodstream infections necessitate rapid identification and management. Automated blood culture systems have revolutionized diagnostic microbiology by expediting pathogen detection and enabling effective clinical interventions. This study assesses the optimal incubation period for blood cultures in a tertiary healthcare setting, aiming to enhance diagnostic accuracy and support antibiotic stewardship. Objective: To evaluate the adequacy of incubation times in blood cultures for producing clinically significant results using an automated system in a tertiary care setting. Methods: This cross-sectional descriptive study was conducted at the Microbiology Section of Combined Military Hospital, Lahore, from October 2022 to March 2023. All patient blood samples processed through the Bactec/Alert system were studied. Positive samples were cultured on Blood and MacConkey agar and incubated at 35 ± 2°C for 24 hours. Positivity rates, contamination, and patient demographics were analyzed using the Laboratory Information Management System. Results: Of the 8,216 blood culture bottles processed, 490 (5.96%) were flagged as positive. Early detection within the first 24 hours was noted in 41.63% (n=204) of cases, with subsequent detections on the second day at 58.65% (n=258), the third day at 5.30% (n=26), and the fourth day at 0.20% (n=1). The isolated pathogens included gram-positive organisms (16.32%, n=80), gram-negative organisms (80.20%, n=393), and Candida spp. (3.46%, n=17). Conclusion: Timely and effective blood culturing is crucial for the diagnostic confirmation of bacteremia, enabling appropriate pathogen identification and antimicrobial therapy. Shortening detection times can significantly impact clinical outcomes, reduce healthcare costs, and promote antimicrobial stewardship.

Comparison of time-to-detection of Mindray TDR and BacT/ALERT®3D blood culture systems using simulated blood cultures

ABSTRACT Purpose Blood culture (BC) is the standard for diagnosing bloodstream infections. Available blood culture (BC) systems have been developed to shorten the time to detection (TTD) of positive BCs. This study aimed to evaluate the performance of the Mindray TDR automatic BC system by comparing it with the BacT/ALERT®3D system. Methods Sixteen reference strains and 14 clinical isolates were used. Serial dilutions were prepared from all bacterial and yeast colonies with a final concentration of 100 CFU/ml and 10 CFU/ml. The prepared solutions were simultaneously inoculated into the bottles of both systems and placed in blood culture devices. Results Three hundred and fifty-two (176 BacT/ALERT®3D and 176 Mindray TDR-X060) blood culture bottles were evaluated, 336 aerobic and 16 anaerobic. At both 10 CFU/ml and 100 CFU/ml dilution, there was no significant difference between the two systems in terms of mean detection times for all isolates (p = 0.965, p = 0.245). When evaluated according to the type of organism, the detection time of gram-positive bacteria at 10 CFU/ml dilution was significantly shorter in the BacT/ALERT system (p = 0.019), whereas detection time for yeasts was significantly shorter with the Mindray system (p = 0.047). The number of anaerobic bacteria was too small to draw statistical conclusions, but we observed a trend of shorter detection times in the Mindray TDR-X060 system. Conclusion Two systems with similar operating principles showed different concentrations-dependent performances in terms of positivity detection times depending on the type of microorganism. Mindray TDR-X060 system has been found to be safe to use at high concentrations with this at lower concentrations further comparative studies are needed on the newly introduced Mindray system.

Clinical and economic evaluation of blood culture whole process optimisation in critically ill adult patients with positive blood cultures

Optimising blood culture processing is important to ensure that bloodstream infections are accurately diagnosed while minimising adverse events caused by antibiotic abuse. This study aimed to evaluate the impact of optimised blood culture processes on antibiotic use, clinical outcomes and economics in intensive care unit (ICU) patients with positive blood cultures. From March 2020 to October 2021, this microbiology laboratory implemented a series of improvement measures, including the clinical utility of Fastidious Antimicrobial Neutralization (FAN® PLUS) bottles for the BacT/Alert Virtuo blood culture system, optimisation of bottle reception, graded reports and an upgraded laboratory information system. A total of 122 ICU patients were included in the pre-optimisation group from March 2019 to February 2020, while 179 ICU patients were included in the post-optimisation group from November 2021 to October 2022. Compared with the pre-optimisation group, the average reporting time of identification and antimicrobial sensitivity was reduced by 16.72 hours in the optimised group. The time from admission to targeted antibiotic therapy within 24 hours after receiving both the Gram stain report and the final report were both significantly less in the post-optimisation group compared with the pre-optimisation group. The average hospitalisation time was reduced by 6.49 days, the average antimicrobial drug cost lowered by $1720.85 and the average hospitalisation cost by $9514.17 in the post-optimisation group. Optimising blood culture processing was associated with a significantly increased positive detection rate, a remarkable reduction in the length of hospital stay and in hospital costs for ICU patients with bloodstream infections.

A novel Colorcult hemoculture in early diagnosis of blood stream infection: A boon in meagre resources

Blood stream infections (BSIs) account for major cause of morbidity and mortality. Conventional hemoculture methods are time consuming, with poor sensitivity and high risk of contamination. Automated blood culture systems are highly sensitive but are overpriced. Hence, it is not suitable for resource poor settings. In this background, this study was done to analyze the sensitivity of novel non automated chemical sensor-based blood culture and to compare the time to detection of both conventional and colorimetric method of blood culture. Blood specimens were collected from 50 study participants, admitted with suspected sepsis, inoculated into the colorcult &amp; conventional culture media and processed as per CLSI guidelines. Culture positive by both conventional and colorcult method was six (12%). Most of the study isolates were Gram negative bacteria (83.4%). The isolates were detected at the earliest within 96 hours by colorcult, whereas by conventional method only three (50 %) were detected within 96 hours and another three (50%) after seven days only. Owing to the escalation in BSIs associated morbidity and mortality, early diagnosis by a simple, cost effective, highly sensitive and specific method is an absolute necessity in resource poor settings. The performance of colorcult is superior to conventional method but cost effective than automated methods and can be used as an alternative method in the diagnosis of BSIs.

Affordable blood culture systems from China: in vitro evaluation for use in resource-limited settings

Bloodstream infections (BSI) pose a significant threat due to high mortality rates and the challenges posed by antimicrobial resistance (AMR). In 2019, an estimated 4.95 million deaths were linked to bacterial AMR. The highest impact was seen in resource-limited settings (RLS). For diagnosis of BSI, performant continuously-monitoring blood culture systems (CMBCS) have been optimized. However, in RLS, the implementation of CMBCS is hindered by budget constraints and unsuitable environmental conditions. Manufacturers from growing economies are currently producing affordable invitro diagnostics, which could fill the gap in capacity, but so far these are not established outside their domestic markets. This study evaluated the performance, usability, and interchangeability of Chinese CMBCS in a laboratory setting using simulated blood cultures with a panel of 20 BSI-associated strains. Four systems were selected for the assessment: Autobio BC60, Mindray TDR60, Scenker Labstar50, and DL-biotech DL-60. Overall, all evaluated CMBCS demonstrated good performance with high yield (96.7-100%) and specificity (97.5-100%), comparable to the reference system (bioMérieux 3D). In addition, when used as "manual" blood cultures in a conventional incubator with visual growth detection, performance was also satisfactory: yield was between 90 and 100% and specificity was 100% for all BCBs. Both the CMBCS and the BCBs were easy to use and lot-to-lot variability in BCBs was minimal. The interchangeability testing indicated that the BCBs from different brands (all except Scenker) were compatible with the various automates, further highlighting the potential for a harmonized "universal BCB." Based on this invitro study, we recommend the use of these systems in settings with challenging environments and limited resources. The Autobio system performed best for automatic detection and DL-Biotech BCBs for manual cultures respectively (combination of performance, price, usability). The appropriateness for use in RLS should still be confirmed in a field study. The study was funded by FIND.

Associated Risk Factors and Clinical Outcomes of Bloodstream Infections among COVID-19 Intensive Care Unit Patients in a Tertiary Care Hospital.

The COVID-19 infection is an ongoing public health crisis causing millions of deaths worldwide. COVID-19 patients admitted to the intensive care unit (ICU) are more vulnerable to acquire secondary bloodstream infections (sBSIs) which cause a significant morbidity and mortality. Thus, we aim to assess the risk factors of sBSIs and outcomes in COVID-19 ICU patients. One hundred blood culture samples with growth (cases) and other 100 blood culture with no growth(controls) were collected.. All the demographic data, laboratory data and antimicrobial resistance pattern were analysed . Blood culture bottle received in the Microbiology laboratory were loaded into Automated blood culture system. Flagged bottles were processed for final identification by MALDI TOF and automated antibiotic susceptibility testing. Flagged bottles were processed for final identification by MALDI TOF and automated antibiotic susceptibility testing. Raised C-reactive protein (CRP) (P = 0.0035), interleukin-6 (P = 0.0404), mechanical ventilation (MV) (P = 0.024), prior antimicrobial exposure (P = 0.002), longer ICU stay with median 11 days (P = 0.022), and higher mortality rate (P = 0.001) were significantly associated with the BSI. A significant proportion of BSIs were Gram-negative bacteria (n = 115) such as Acinetobacter baumannii 38 (33%) and Klebsiella pneumoniae 30 (26%). Monomicrobial organisms in blood yielded a higher proportion in our study 72 (72%). The highest resistance for Acinetobacter species (50) was observed with ceftazidime 29 (96.6%) amikacin 48 (96%), meropenem 48 (96%), cefotaxime 47 (94%), ciprofloxacin 46 (92%), and netilmicin 46 (92%). K. pneumoniae was highly resistant to cefotaxime 29 (96.6%), ceftazidime 29 (96.6%), ciprofloxacin 22 (73.3%), and cefuroxime 21 (70%). Among Gram-positive organisms, Enterococcus species showed that a resistance for high-level gentamicin and penicillin was 66.6%. Raised CRP, need of MV, prior antimicrobial exposure, and longer ICU stay should alarm clinicians for BSI. Hence, our study highlights the associated risk factors for BSI and emphasizes adherence to hospital infection control policies and antibiotic stewardship program.

Culture-negative endocarditis with multifocal spread and flail mitral valve leaflet: a case report

Introduction: Blood culture-negative infective endocarditis is the condition in which a causative organism cannot be identified after inoculation of at least three samples using standard blood-culture systems for 7 days. It has a low reported incidence of about 2.5–31%. Causes may be infectious or non-infectious; use of prior antibiotic therapy is usually the leading factor. Case presentation: The authors present a case of true culture-negative endocarditis involving the mitral valve, with multiple foci of spread including brain, spleen, liver, and Intervertebral disc, which remained persistent despite treatment with intravenous broad-spectrum antibiotics on an inpatient and outpatient basis but eventually improved after upgrading alternative broad-spectrum antibiotic for an extended duration. The patient had complications in the form of a flail mitral valve with persistent mitral regurgitation, requiring mitra-clip placement. Discussion: Positive blood culture is one of the major diagnostic criteria to establish infective endocarditis. Patients may have persistent negative cultures due to previous antibiotic use, the presence of fastidious organisms, or the use of inappropriate techniques or media. Involvement of a multidisciplinary team, use of multimodal investigations, and appropriate antibiotic stewardship are crucial. Extended duration of treatment and upgrading antibiotics can be helpful next steps in highly suspicious cases. With multifocal spread as in our case, it further becomes challenging to control and treat the infection as it is frequently connected with higher morbidity and mortality. Conclusion: Blood culture-negative endocarditis is an entity that can present with early complications. It is diagnostically and therapeutically challenging to treat such patients. Multimodal approaches for early diagnosis and appropriate treatment are crucial owing to its high morbidity and mortality.

Bacteriological Profile of Bloodstream Infections in Paediatric Oncology Patients with Febrile Neutropenia: A Five-year Ambispective Study at a Tertiary Care Centre in Northern India

Introduction: Bloodstream Infections (BSI) are known to be responsible for significant mortality and morbidity. Cancer patients, being immunosuppressed, are more vulnerable to developing infections and often present with Febrile Neutropenia (FN). Aim: To determine the epidemiology, microbiology, and antibiotic susceptibility pattern among paediatric cancer patients admitted with FN. Materials and Methods: This ambispective study was conducted over a period of 5 years, from April 2018 to April 2023, in the Department of Paediatric Oncology in coordination with the Department of Microbiology at Sher-i-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India. Isolates collected from April 2018 to April 2022 were retrospectively evaluated with respect to gender, age, and severity of neutropenia, whereas those analysed prospectively were from May 2022 to April 2023. Data from 328 patients presenting with 420 episodes of FN were obtained, including information on age, gender, the organism isolated, and antibiotic susceptibility pattern. Blood samples were collected in blood culture bottles and incubated at 35±2°C in the automated BACT/ALERT blood culture system. Positive bottles were further subjected to manual identification and antibiotic susceptibility testing of the bacterial isolates using the Kirby Bauer disk diffusion method. The results were interpreted according to the Clinical and Laboratory Standards Institute guidelines of 2023. All statistical analyses were performed using Statistical Package for Social Sciences (SPSS) software v.23. Results: A total of 328 patients were admitted over the five- year period, with 420 episodes of FN. The culture positivity rate was 81 out of 420 (19.2%). Among the patients, 50 (61.7%) were males, and 36 (45%) had moderate neutropenia at the time of admission. The most common malignancy was Acute Lymphoblastic Leukaemia (ALL), accounting for 25 cases (30.8%), followed by neuroblastoma with 13 cases (16%) and retinoblastoma with 1 case (1.2%). Coagulase-negative Staphylococci (CoNS) were isolated in 21 cases (25.9%). Furthermore, 12 (75%) of the Staphylococcus isolates and 12 (57.14%) of the CoNS were found to be methicillin-resistant. Among the gram-negative bacteria, Acinetobacter baumanii showed the highest resistance to the tested antibiotics. Conclusion: The majority of cases were moderately neutropenic, and CoNS was found to be the most common pathogen in BSI. None of the isolates were pan drug-resistant. Empiric antibiotic treatment for FN should be tailored to the locally prevalent pathogens and their susceptibility patterns. This approach will aid in appropriate infection control practices, ultimately reducing mortality and morbidity in affected patients.

New Antibiotic Binding Resin Bottles Collected from Children Enhances Rapid Microbial Identification.

Bloodstream infections (BSI) represent a common cause of sepsis and mortality in children. Blood culture (BC) is the gold standard for diagnosis of BSI. The low sensitivity of BC in the pediatric population is usually due to the small volume of blood used for inoculation and to the antibiotics used before sampling. Here, we explore the ways to effectively reduce antibiotic activity to maximize the chances of pathogen recovery, and to enhance the growth of microorganisms in lower blood volume and bacterial counts. The recovery of common pathogens causing blood stream infections was analyzed after exposure to cefo-perazone/sulbactam, vancomycin, and caspofung by using resin-containing or not BacT/Alert PF Plus and BD FX400 peds plus pediatric bottles. The microbial growth in the resin-containing bottles was assessed using 0.5 colony-forming units (CFU) bacterial inoculum to mimic the bacteremia/fungemia condition. The usefulness of a diagnosis to confirm or exclude BSI was evaluated by lower than recommended blood culture sampling (102 CFU/mL, 0.3 mL). Staphylococcus aureus (S. aureus), and Candida glabrata (C. glabrata) were recovered from 100% of two types of resin-containing bottles in the presence of a sufficient antibiotic dose, while Escherichia coli (E. coli) was not restored to 100% in BD FX400 peds plus pediatric bottles. The shorter TTD for S. aureus, C. glabrata, and E. coli were observed in antibiotic-containing BacT/Alert PF Plus bottles. Both the PF Plus and BD resin test bottles showed consistently good TTD performances to Gram-negative, Gram-positive, and yeast species in low inoculum levels, with the exception of S. aureus. The lower volume of blood inoculated into culture bottles hardly affected the growth of most bacteria, but optimized PF Plus resin-bottles accelerated the detection of infectious agents, especially S. aureus, Streptococcus pneumoniae, and C. glabrata. It is possible to enhance recovery from antibiotic-containing pediatric bottles and shorten TTD for the identification of pathogens by using the BacT/Alert blood culture system combination with new resin-containing media.

Influence of filtering on the effective concentration and sterility of a 2% cyclosporine ophthalmic solution: a quality improvement perspective

BackgroundPharmaceutical companies do not sell formulations for all diseases; thus, healthcare workers have to treat some diseases by concocting in-hospital preparations. An example is the high-concentration 2% cyclosporine A (CyA) ophthalmic solution. Utilizing a filter in sterility operations is a general practice for concocting in-hospital preparations, as is the case for preparing a 2% CyA ophthalmic solution. However, whether filtering is appropriate concerning the active ingredient content and bacterial contamination according to the post-preparing quality control of a 2% CyA ophthalmic solution is yet to be verified.MethodsWe conducted particle size, preparation concentration, and bacterial contamination studies to clarify aforementioned questions. First, we measured the particle size of CyA through a laser diffraction particle size distribution. Next, we measured the concentration after preparation with or without a 0.45-µm filter operation using an electrochemiluminescence immunoassay. Finally, bacterial contamination tests were conducted using an automated blood culture system to prepare a 2% CyA ophthalmic solution without a 0.45 μm filtering. Regarding the pore size of the filter in this study, it was set to 0.45 μm with reference to the book (the 6th edition) with recipes for the preparation of in-hospital preparations edited by the Japanese Society of Hospital Pharmacists.ResultsCyA had various particle sizes; approximately 30% of the total particles exceeded 0.45 μm. The mean ± standard deviation of filtered and non-filtered CyA concentrations in ophthalmic solutions were 346.51 ± 170.76 and 499.74 ± 76.95ng/mL, respectively (p = 0.011). Regarding bacterial contamination tests, aerobes and anaerobes microorganisms were not detected in 14 days of culture.ConclusionsDue to the results of this study, the concentration of CyA may be reduced by using a 0.45-µm filter during the preparation of CyA ophthalmic solutions, and furthermore that the use of a 0.45-µm filter may not contribute to sterility when preparing CyA ophthalmic solutions.

Performance evaluation of 4-day versus 5-day blood cultures using the BD BACTEC FX system

Background: Blood culture (BC) systems have evolved to increase sensitivity and reduce turnaround times. This study compared the performance of a 4-day versus a 5-day BC incubation period using the BD BACTEC™ FX (Becton, Dickinson and Company, USA). Methods: A total of 37,379 consecutive sets of BC were evaluated over a 3-month period in a 2,700-bed tertiary care hospital. Positive BC results were reviewed to assess time-to-positivity (TTP) and species identification of the isolates. The BCs were performed in pairs of vials, utilizing either BD BACTEC Plus Aerobic/F or Peds Plus/F with BD BACTEC Lytic Anaerobic media. Results: A total of 14,899 episodes, averaging 2.51 sets per episode, were analyzed. Of these, 1,398 (9.38%) were positive, yielding 1,465 isolates. TTP (hours) were &lt; 12 in 48.87%, 12-24 in 31.40%, 24-48 in 13.38%, 48-72 in 3.28%, 72-96 in 1.43%, and &gt;96 in 1.64%. The two most prevalent organisms, Escherichia coli and Klebsiella spp. were detected within 12 hours in 88.75% and 78.90%, respectively. The respective median TTP (T50) values for E. coli, Klebsiella spp., Enterococcus faecalis/E. faecium, and Staphylococcus aureus were 9.24, 9.60, 13.75, and 14.20. T50 values for these species were significantly shorter in anaerobic bottles than in aerobic bottles. Of 24 BCs with TTP &gt; 96, only 4 containing anaerobic bacteria or molds were f irst detected after 96 hours. Conclusion: A 4-day incubation has demonstrated excellent sensitivity. However, a 5-day incubation may be beneficial for hospitals caring for patients at high risk for infections with slow-growing fungi or fastidious bacteria.

Short communication: first case of bacteraemia causedby Dielma fastidiosa in a patient hospitalized with diverticulitis.

Dielma fastidiosa is a gram-negative, anaerobic rod belonging to the family Erysipelotrichaceae. D. fastidiosa has previously been isolated in human stool samples as part of the commensal flora; however, prior to this case, it has never been identified as a human pathogen. We present the first case of bacteraemia with D. fastidiosa. Bacterial growth in the blood culture bottle was detected by the automated blood culture system BacT/ALERT 3D. Culturing was performed, and bacterial colonies were identified as D. fastidiosa using MALDI-TOF MS. A subsequent whole-genome sequencing using Illumina NovaSeq was performed, and a phylogenetic tree depicting all available sequences of D. fastidiosa was generated. The reference MALDI-TOF spectrum and species identification was compared with the previously published spectrum. Whole-genome sequencing confirmed the tentative MALDI-TOF species identification. Notably, the maximum-likelihood-based phylogenetic analysis placed the D. fastidiosa isolate from this clinical case within the known variation of the eight publicly available sequences of this species. We identified D. fastidiosa by whole-genome sequencing followed by maximum-likelihood analysis as a possible pathogen in this case of bacteraemia in a patient hospitalized with diverticulitis.