Explore the vast range of titles available.

Background Droplet 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. Methods A 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. Results A 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 bla KPC , 3 bla NDM , and 38 mec A genes were detected, among which 90.5% were definitely positive for bla KPC . Further, 65.8% specimens were predicted to be mec A-positive in Staphylococcus sp. according to all microbiological analysis. Conclusions The 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.

The corrected sentence appears below: “This study was conducted per the guidelines of the Declaration of Helsinki and approved by the Institutional Ethics Committee of the Shoolini University with reference number: A correction has been made to Methods, Study design and sample collection, 1st Paragraph. A correction has been made to Ethics statement, This sentence previously stated: “This study was conducted per the guidelines of the Declaration of Helsinki and approved by the Institutional Ethics Committee of the Post-Graduate Institute of Medical Education with reference number: 2022-EC-025 which complies with international ethical standards…” The corrected sentence appears below: “This study was conducted per the guidelines of the Declaration of Helsinki and approved by the Institutional Ethics Committee of the Shoolini University with reference number:

Objectives Methicillin-resistant Staphylococcus aureus (MRSA) is a challenging global health threat, resulting in significant morbidity and mortality worldwide. This study aims to determine the molecular characteristics and antimicrobial susceptibility of 263 MRSA isolates in Zhejiang Province, east China. Methods From 2014 to 2019, a total of 263 MRSA isolates from bloodstream infections (BSIs) were collected from 6 hospitals in 4 cities in Zhejiang province, east China. Antimicrobial susceptibility tests were conducted according to the guidelines set forth by the Clinical and Laboratory Standards Institute (CLSI). To characterize and analyze these isolates, multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCC mec ) typing, staphylococcal protein A ( spa ) typing and virulence genes gene profiles were performed. Results The most predominant clone was ST5-SCC mec II-t311, which accounted for 41.8% (110/263), followed by ST59 (44/263, 16.7%). Compared with non-ST5-II-t311 isolates, ST5-II-t311 isolates were more resistant to erythromycin, tetracycline, levofloxacin, moxifloxacin, and ciprofloxacin, but more susceptible to clindamycin. Moreover, the rates of multidrug resistance were higher in ST5-II-t311 isolates compared to the non-ST5-II-t311 isolates. In comparison to the non-ST5-II-t311 isolates, ST5-II-t311 isolates showed no significant difference in virulence genes detected. Conclusions MRSA ST5-II-t311 clone has become the most predominant clone in Zhejiang Province, east China and has higher rates of multidrug resistance than other isolates, that should be kept in mind when treating BSI. Moreover, MRSA ST59 clone shows an upward trend and has begun to spread into hospitals. Our findings highlight the importance of epidemiological studies of S. aureus carriage in the eastern region.

Objective Bloodstream infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) are a significant public health problem, with high morbidity and mortality. Detection and identification of CRAB is essential for early diagnosis and treatment. Therefore, a rapid and economical method for the detection of CRAB-associated Bloodstream infections (BSIs) is urgently needed. Methods A triple PCR-UV reaction system has been developed for the detection of the antibiotic resistance genes OXA23 , OXA51 and AB-specific gene. Primer specificity, limit of detection (LOD), reproducibility, and accuracy of the assay were evaluated. The PCR products were directly analyzed using UV and ImageJ analysis, which provided a quickly interpretation of the results. Furthermore, the established assay was validated on clinical isolates and compared with blood culture and drug susceptibility testing. Results The triple PCR-UV method established in this study demonstrated strong primer specificity and discriminated CRAB among 23 common clinical pathogens. The results of this PCR method were validated by electrophoresis and showed good accuracy and reproducibility, with a limit of detection (LOD) of 3.0 × 10 –1 ng/uL. Meanwhile, the optimal annealing temperature for the triple method has been optimized to 56.4 ℃. The result of PCR amplification could be judged by the result of the gray value of the tube to be tested / the gray value of the blank control of the same lot. The ratio > 1.3 is CRAB, the ratio between 1.1–1.3 is carbapenem-sensitive Acinetobacter baumannii (CSAB), the ratio < 1.1 is negative result. When applied to detect 30 patients with BSIs of AB, the results were consistent with clinical blood culture identification and drug susceptibility testing. Conclusion The triple PCR-UV assay developed in this study is a UV-visual, rapid, and cost-effective method for the detection of Acinetobacter baumannii (AB ) and identification of CRAB in bloodstream infections. The assay could be particularly useful in community settings where expensive molecular instrumentation is not readily available and could help in the diagnosis and management of CRAB infections in BSIs.

Accurate identification of infectious diseases using molecular techniques, such as PCR and NGS, is well-established. This study aims to assess the utility of Bactfast and Fungifast in diagnosing bloodstream infections in ICU settings, comparing them against traditional culture methods. The objectives include evaluating sensitivity and specificity and identifying a wide range of pathogens, including non-culturable species. We collected 500 non-duplicate blood samples from ICU patients between January 2023 and December 2023. Specimens underwent traditional culture, MALDI-TOF, VITEK 2 compact system, and NGS-based Bactfast and Fungifast analyses. Out of the 500 samples, 26.8% (n=134) showed bacterial growth via traditional culture methods, while 4.8% (n=24) were positive for fungal growth. MALDI-TOF and VITEK 2 compact system yielded comparable results, identifying 26.4% (n=132) of specimens with bacterial growth. NGS-based Bactfast detected bacterial presence in 38.2% (n=191) of samples, including non-culturable bacteria missed by traditional methods. However, NGS-based Fungifast showed concordant fungal detection rates with culture methods. Among identified pathogens by culture method included 20.89% (n=28), 18.65% (n=25), 15.67% (n=21), 12.68% (n=17), 10.44% (n=14), various species 7.46% (n=10), 6.71% (n=9), 4.47% (n=6), and 2.98% (n=4). Non-culture-based NGS identified additional (n=33) pathogens, including 27.27% (n=9), 21.21% (n=7), 15.15% (n=5), 12.12% (n=4), 9% (n=3), 9% (n=3), and 6% (n=2). was reported in 5% (n=24) of samples by both methods. NGS-based Bactfast and Fungifast demonstrate high sensitivity in identifying a wide array of bacterial and fungal pathogens in ICU patients, outperforming traditional culture methods in detecting non-culturable organisms. These molecular assays offer rapid and comprehensive diagnostic capabilities, potentially improving clinical outcomes through timely and accurate pathogen identification.

Congenital heart disease (CHD) profoundly impacts pediatric health, leading to increased morbidity and complex care requirements, often resulting in prolonged hospital stays. Nosocomial infections, particularly bloodstream infections (BSIs), pose a significant risk in the Pediatric Cardiac Intensive Care Unit (PCICU). This study aims to evaluate the prevalence of nosocomial BSIs in children with CHD within the PCICU and to identify associated risk factors. A retrospective analysis was conducted on data recorded from patients under 18 years of age who had confirmed positive blood cultures and were hospitalized for a minimum of 48 hours from March 2019 to March 2022. Demographic, clinical, and microbiological information was collected, and statistical analyses were performed to determine the relationships between various risk factors and positive blood cultures. In this analysis of 510 patients evaluated, positive blood cultures were found in 16.7% of patients. Patients with positive cultures were significantly younger and had lower mean weights (P<0.05). Recovery status was a significant predictor of blood culture results (p<0.001). Device utilization, including urinary catheters and central venous lines, was notably higher in the positive culture group (P<0.05). Additionally, a higher proportion of patients with positive cultures had acyanotic CHD, with significant associations for Patent Ductus Arteriosus (PDA), Ventricular Septal Defect (VSD), and Atrial Septal Defect (ASD) (P<0.001). Improved recovery status decreased the likelihood of positive blood cultures by approximately 52.2% (odds ratio 0.478, p=0.0021). Our findings reveal a high prevalence of BSIs in the PCICU, highlighting some associated risk factors such as recovery status, use of central vein catheters, dialysis and Foley catheters, younger age, and lower weight. This study emphasizes the necessity for rigorous infection control measures, particularly regarding the management of invasive devices and prompt clinical interventions, to improve patient outcomes in this high-risk population. Enhanced surveillance and tailored guidelines are essential for reducing the risks of nosocomial infections in pediatric cardiac care settings.

Background: Vancomycin-resistant enterococci (VRE) rectal colonization represents a critical risk factor for subsequent bloodstream infections (BSIs), posing a serious concern in healthcare settings. This study aims to investigate the association between the presence of VRE in rectal swabs and the occurrence of BSIs, highlighting the challenges of rapid detection and patient care implications in an infectious disease hospital setting. Methods: We performed a retrospective analysis of cultural rectal swab screening and molecular assays (MAs) for VRE detection between January 2020 and December 2023. All adult patients admitted with at least one rectal swab screening performed during hospitalization were included. All blood cultures that yielded VRE were identified, and the first Enterococcus-positive blood sample for each patient with at least one prior rectal swab per year was analyzed. Results: The results showed a 15.4% positivity rate for VRE in cultural screening, predominantly Enterococcus faecium. MA showed a higher prevalence of 49.4%, with a significant discordance between MA rectal swab screening and cultural testing. Patients with VRE intestinal colonization by E. faecium were significantly more likely to develop E. faecium BSI, with a risk ratio of 9.78 (p < 0.001). Conclusions: The study identified a strong correlation between VRE rectal colonization and the risk of developing BSI, emphasizing the need for effective screening and infection control measures. The results support the inclusion of molecular testing in VRE detection protocols and highlight the importance of ongoing surveillance for antimicrobial resistance.

Droplet digital PCR (ddPCR) recently has been shown to be a potential diagnostic tool for adults with bloodstream infections (BSIs); however, its application in children remains obscure. In this study, 76 blood samples of children with suspected BSIs were synchronously detected by traditional blood cultures (BCs) and ddPCRs. Our team validated the diagnostic performance of ddPCR including sensitivity, specificity, and positive and negative predictive values. The 76 pediatric patients from the hematology department (67.1%), the pediatric intensive care unit (PICU, 27.6%), and other departments (5.2%) were enrolled. The positive rate of ddPCR results was 47.9%, whereas that for BC was 6.6%. In addition, the time consumption of ddPCR was shorter, only for 4.7 ± 0.9 h, in comparison with the detection timing of BC (76.7 ± 10.4 h, p < 0.01). The levels of agreement and disagreement between BC and ddPCR were 96.1% and 4.2%, and the negative agreement reached 95.6%. The sensitivity of ddPCR was 100%, with corresponding specificities ranging from 95.3 to 100.0%. In addition, a total of nine viruses were identified by ddPCR. In China, the multiplexed ddPCR first could be a tool for the rapid and accurate diagnosis of children with suspected BSIs and can be an early indicator of the possibility of viraemia in children with immunosuppression.

The prevalence of Candida in bloodstream infections (BSIs) has increased. To date, the identification of Candida in BSIs still mainly relies on blood culture and serological tests, but they have various limitations. Therefore, a real-time PCR assay for the detection of Candida from whole blood is presented. The unique primers/probe system was designed on 5.8S rRNA gene (5.8S rDNA) of Candida genus. The analytical sensitivity was determined by numbers of positive PCRs in 12 repetitions. At the concentration of 10 1  CFU/ml blood, positive PCR rates of 100 % were obtained for C. albicans , C. parapsilosis , C. tropicalis , and C. krusei . The detection rate for C. glabrata was 75 % at 10 1 CFU/ml blood. The reaction specificity was 100 % when evaluating the assay using DNA samples from clinical isolates and human blood. The maximum CVs of intra-assay and inter-assay for the detection limit were 1.22 and 2.22 %, respectively. To assess the clinical applicability, 328 blood samples from 82 patients were prospectively tested and real-time PCR results were compared with results from blood culture. Diagnostic sensitivity of the PCR was 100 % using as gold standard blood culture, and specificity was 98.4 %. Our data suggest that the developed assay can be used in clinical laboratories as an accurate and rapid screening test for the Candida from whole blood. Although further evaluation is warranted, our assay holds promise for earlier diagnosis of candidemia.

This chapter contains sections titled: Introduction Common HAIs Epidemiology of Infectious Disease and the Hospital and Ambulatory Care Environment The Agent, Host, and the Environment References