Optimizing the number of blood cultures for lower and middle income countries: a large scale study in a public sector tertiary care teaching hospital of Southern India

Background: Blood culture is widely accepted as the gold standard investigation for the diagnosis of blood stream infections (BSI). The number of blood cultures collected has a considerable impact on the organism isolation. This study aims to optimize the number of blood cultures needed, for an optimal diagnostic yield in BacT/ALERT VIRTUO system mainly in a resource limited setting. Methods: All the blood cultures (BCs) obtained in BacT/Alert bottles per patient during a 24-h period were included as ‘one episode’ and categorized as single bottle, 1-set (2 aerobic bottles), 2 sets and 3 sets. BC bottles were incubated in the BacT/ALERT VIRTUO (bioMérieux) for a period of five days. Bottles flagged positive were subjected to Gram staining and culture plating. Colonies grown were identified by MALDI-TOF MS, VITEK MS, bioMérieux. Results: Cumulative positivity rate increased (21.7%, 41.4%, 56.1%, 60.6%) and pathogen isolation rate increased (10.3%, 21.8%, 30.4% and 33.8%) progressively when collected in single bottle, 1, 2 and 3 sets respectively. The pathogen detection rate for GNB and GPC were 45.1% and 42.6% respectively with one bottle and this got upsurged to 85.6% and 98.9% for GNB and 83.6% and 98.2% for GPC when collected in ≤1 set and ≤2 sets respectively. Conclusions: Two BC sets over a 24-h period can detect approximately 98% of the pathogens with a cumulative positivity rate of 60% and hence it is a justifiable alternative approach to the standard practice of 3-sets of BCs

Neonatal invasive candidiasis in low-and-middle-income countries: data from the NeoOBS study

Neonatal invasive candidiasis (NIC) has significant morbidity and mortality. Reports have shown a different profile of those neonates affected with NIC and of fluconazole resistant Candida spp. isolates in low-and-middle-income -countries (LMICs) compared to high-income-countries (HIC). We describe the epidemiology, Candida spp. distribution, treatment and outcomes of neonates with NIC from LMICs enrolled in a global, prospective, longitudinal, observational cohort study (NeoOBS) of hospitalised infants < 60 days postnatal age with sepsis (August 2018-February 2021). 127 neonates from 14 hospitals in 8 countries with Candida spp. isolated from blood culture were included. Median gestational age of affected neonates was 30 weeks (IQR: 28-34) and median birth weight was 1270 g (IQR: 990-1692). Only a minority had high risk criteria, such as being born < 28 weeks, 19% (24/127), or birth weight < 1000 g, 27% (34/127). The most common Candida species were C. albicans (n = 45, 35%), C. parapsilosis (n = 38, 30%) and Candida auris (n = 18, 14%). The majority of C. albicans isolates were fluconazole susceptible, whereas 59% of C. parapsilosis isolates were fluconazole resistant. Amphotericin B was the most common antifungal used [74% (78/105)], followed by fluconazole [22% (23/105)]. Death by day 28 post-enrolment was 22% (28/127). To our knowledge, this is the largest multi-country cohort of NIC in LMICs. Most of the neonates would not have been considered at high risk for NIC in HICs. A substantial proportion of isolates was resistant to first choice fluconazole. Understanding the burden of NIC in LMIC is essential to guide future research and treatment guidelines

Surrogate markers and their correlation to bacterial contamination and other quality parameters in random-donor platelets by platelet-rich plasma method

Introduction: Bacterial contamination in platelet concentrates (PCs) occurs more frequently than other blood components because of several factors such as storage in oxygen permeable blood bags at 20°C–24°C with continuous agitation which facilitates bacterial growth compared to other blood components which are kept frozen or refrigerated which inhibits bacterial proliferation in them. The purpose of the study was to assess the incidence of bacterial contamination of random-donor PCs and factors associated with its contamination and see how well the surrogate markers such as pH and swirling correlate with the same. Methodology: This was a cross-sectional study which included randomly chosen 500 random-donor platelets (RDPs) in blood bank prepared by platelet-rich plasma method. The samples chosen for the study were from the RDPs on the 5th day of storage after their preparation. pH, platelet count, and swirling in platelets, which act as surrogate markers for bacterial contamination, were checked on the RDP units. About 1–3 ml of PCs was inoculated from the RDP units into labeled culture bottles (BD Bactec Peds Plus/F). Results: Among a total of 499 random-donor PCs that were cultured in the automated BACTEC system for the study, none of them were culture positive. Thirty RDP units in the study were visibly lipaemic whereas 93 RDP units were visibly reddish in appearance. PCs having volumes 70 ml did not affect the swirling, pH, and platelet counts. There was a statistically significant difference between mean pH with RDP units having swirling Grade 2 and 3 and platelet counts with RDP units having swirling Grade 1 and 2. Conclusion: Bacterial contamination though poses a significant risk is a very rare event in a meticulously prepared and stored PCs. Surrogate markers though useful in resource-constrained settings does not correlate optimally with the quality indicators

PHENOTYPIC DETECTION OF CARBAPENEM RESISTANCE IN CLINICAL ISOLATES OF ACINETOBACTER BAUMANII IN KANCHIPURAM

ABSTRACT: Acinctobacter species are common non fermentative gram negative bacilli isolated in clinical laboratory most frequently encountered species. Acinetobacter resistance is develop due to acquired resistance. Because of frequent multidrug resistance isolates carbapenems have become important for treating resistant strains. There is a need for rapid screening &amp; detection of MBL in Acinetobacter to modify the treatment. The present study was aim to determine the resistance of A.baumanii complese to various classes of drugs and to carbapenems and MBL production. Samples such as urine, blood, sputum, pus &amp; body fluids. All samples were processed as per CLSI guidelines. Meropenem resistant strains were screened for carbapenemase and MBL production. Out of 92 Acinetobacter 85 (92.39%) were Acinetobacter baumanii. More than 80 % resistance is seen in 3 rd generation Cephalosporins. Out of 21 meropenem resistant strains 14 were carbapenemase positive and 3 were MBL producers. Our study shows raising trend of multidrug resistance and carbapenem. This will help in early detection and better treatment modalities

Comparison of four different methods of smear preparation for Gram staining of positively flagged automated blood culture bottles

Introduction: Gram staining of smears prepared from positively flagged blood culture bottles plays a vital role because its accurate interpretation helps the clinicians to modify empirical therapy as well as to perform the direct susceptibility test, which reduces the turnaround time by 24 h to initiate pathogen-directed antimicrobial therapy. However, the interpretation of direct Gram stain from blood culture bottles has always been at risk of errors in interpreting. Aim: The present study was conducted to find the agreement between the blood culture broth Gram stain finding of four different methods (conventional, water wash, blood film, and drop and rest) of smear preparation with the culture smear Gram stain result and also to compare the quantity of charcoal and resin particles present in the Gram stained smears made from four different smear preparation methods. Method and Result: Smears were made from 500 positively flagged automated blood culture bottles using the four different methods and then compared for agreement with the culture smear Gram stain using kappa statistics and were found to be maximum for the blood film method (0.637), followed by drop and rest (0.570), water-wash (0.496), and conventional method (0.475). The 3+ grading for resin/charcoal was found in 184 (36.80%) smears, 169 (33.80%), 93 (18.60%), and 26 (5.20%) smears prepared by water-wash, conventional, drop and rest, and blood film method, respectively. The interference caused by resin/charcoal was maximum when smears were prepared by the conventional method resulting in high inaccurate interpretation. Conclusion: In this study, the agreement between direct smear preparation methods from positively flagged blood culture broth with the culture smear Gram stain was found to be maximum for the blood film method, followed by drop and rest, waterwash, and conventional method.It was also observed that the least amount of resin/charcoal was encountered when the direct smears were prepared using the blood film method.Hence, we found that the blood film method helps in interpreting the Gram stained smears from positively flagged blood culture broth more accurately compared to other methods

Neonatal invasive candidiasis in low- and middle-income countries: data from the NeoOBS study

Neonatal invasive candidiasis (NIC) has significant morbidity and mortality. Reports have shown a different profile of those neonates affected with NIC and of fluconazole-resistant Candida spp. isolates in low- and middle-income countries (LMICs) compared to high-income countries (HICs). We describe the epidemiology, Candida spp. distribution, treatment, and outcomes of neonates with NIC from LMICs enrolled in a global, prospective, longitudinal, observational cohort study (NeoOBS) of hospitalized infants <60 days postnatal age with sepsis (August 2018–February 2021). A total of 127 neonates from 14 hospitals in 8 countries with Candida spp. isolated from blood culture were included. Median gestational age of affected neonates was 30 weeks (IQR: 28–34), and median birth weight was 1270 gr (interquartile range [IQR]: 990–1692). Only a minority had high-risk criteria, such as being born <28 weeks, 19% (24/127), or birth weight <1000 gr, 27% (34/127). The most common Candida species were C. albicans (n = 45, 35%), C. parapsilosis (n = 38, 30%), and Candida auris (n = 18, 14%). The majority of C. albicans isolates were fluconazole susceptible, whereas 59% of C. parapsilosis isolates were fluconazole-resistant. Amphotericin B was the most common antifungal used [74% (78/105)], followed by fluconazole [22% (23/105)]. Death by day 28 post-enrollment was 22% (28/127). To our knowledge, this is the largest multi-country cohort of NIC in LMICs. Most of the neonates would not have been considered at high risk for NIC in HICs. A substantial proportion of isolates was resistant to first choice fluconazole. Understanding the burden of NIC in LMIC is essential to guide future research and treatment guidelines