Bloodstream Infection Etiology among Children and Adults

Incidence, causative organisms, and risk factors of bloodstream infections in pediatric liver transplant patients: a systematic review

Bacterial bloodstream infections (BSI) are the leading cause of mortality and morbidity in pediatric solid organ transplant recipients. This systematic review aimed to pool global data from leading transplant institutions and identify the overall incidence, risk factors, and causative organisms of BSI in pediatric liver transplant recipients. A systematic review of the PubMed and OVID databases was conducted from 2000 to 2022. The initial search yielded 252 unique articles, which were independently reviewed by 2 authors. Articles that reported pediatric-specific data on BSI in isolated liver transplant patients were included, including the incidence of BSI, isolated organisms, and involved risk factors involved. This systematic review was registered with PROSPERO (ID: CRD42023403206). Fourteen articles from the United States, France, Iran, Japan, Korea, South Africa, Thailand, and Turkey were included. A total of 4,812 liver transplants were included in the final analysis. The mean patient age was 25 months (age range, 0-18 years), and 50.9% were male. The overall incidence of BSI was 23.5% (range, 14.7%-55%). The most commonly reported organisms were Staphylococcus epidermidis, Enterococcus, Klebsiella spp., and Escherichia coli. Among the risk factors studied, postope rative biliary complications, a medical history of biliary atresia, and younger age were the risk factors most commonly associated with BSI. Bacterial BSI after pediatric liver transplantation occur at a high incidence, with a unique organism profile notable for a higher percentage of gram-negative organisms. Further studies are required to determine the most appropriate prophylactic and empirical antibiotic management strategies for this population.

Aerobic Bacterial Profile of Sepsis and Its Antibiotic Susceptibility Pattern Among Patients in a Rural Tertiary Care Center

Background Bloodstream infections (BSI) are one of the most life-threatening infections associated with high morbidity and mortality. Early diagnosis with appropriate and timely treatment improves the patient outcome. The recent surge in multidrug-resistant (MDR) strains is a matter of concern. This study aims to determine the bacterial etiology and antibiotic sensitivity pattern in BSI among different age groups. Materials and methods The microbiological data of blood culture and sensitivity between April 2019 and April 2021 were extracted from the laboratory records and analyzed for the bacterial profile and antibiotic sensitivity pattern. Results Out of the total 3893 blood cultures received during the study period from April 2019 to April 2021, 194 pathogens were isolated, accounting for a prevalence of 4.98%. Among 194 patients with culture-proven BSI, 54.12% (105/194) were adults, and 45.87% (89/194) were children. Of these 194 bacterial isolates, 58.76% (114/194) were gram-negative bacteria, and 41.24% (80/194) were gram-positive bacteria. With regard to the bacteria isolated, Enterococcus species with 23.71% (46/194) and Acinetobacter species with 22.16% (43/194) were the most common bacteria. The prevalence of MDR was 59.27% (115/194). Notable MDR types were methicillin-resistant Staphylococcus aureus (MRSA) in 15/22 (68.2%) and extended-spectrum beta-lactamase (ESBL) producers in 15/48 (31.25%) cases. Conclusion There is a significant geographical diversity of bacteria causing sepsis and their antibiotic susceptibility pattern. Recent trends show that multidrug-resistant gram-negative bacilli are the predominant isolates causing BSI. Increased antibiotic resistance is leading to treatment failure and poor clinical outcomes. Hence, there is a need to monitor antibiotic resistance among patients with BSI.

Development of a novel integrated isothermal amplification system for detection of bacteria-spiked blood samples

Bloodstream infection (BSI) caused by bacteria is highly pathogenic and lethal, and easily develops whole-body inflammatory state. Immediate identification of disease-causing bacteria can improve patient prognosis. Traditional testing methods are not only time-consuming, but such tests are limited to laboratories. Recombinase polymerase amplification combined with lateral flow dipstick (RPA-LFD) holds great promise for rapid nucleic acid detection, but the uncapping operation after amplification easily contaminates laboratories. Therefore, the establishment of a more effective integrated isothermal amplification system has become an urgent problem to be solved. In this study, we designed and fabricated a hermetically sealed integrated isothermal amplification system. Combining with this system, a set of RPA-LFD assays for detecting S. aureus, K. peneumoniae, P. aeruginosa, and H. influenza in BSI were established and evaluated. The whole process could be completed in less than 15 min and the results can be visualized by the naked eye. The developed RPA-LFD assays displayed a good sensitivity, and no cross-reactivity was observed in seven similar bacterial genera. The results obtained with 60 clinical samples indicated that the developed RPA-LFD assays had high specifcity and sensitivity for identifying S. aureus, K. peneumoniae, P. aeruginosa, and H. influenza in BSI. In conclusion, our results showed that the developed RPA-LFD assay is an alternative to existing PCR-based methods for detection of S. aureus, K. peneumoniae, P. aeruginosa, and H. influenza in BSI in primary hospitals.

Mortality Risk Factors of Early Neonatal Sepsis During COVID-19 Pandemic

Purpose

This study aimed to determine predisposing factors for negative outcome in infants with early neonatal sepsis during COVID-19.

Patients and Methods

A prospective cohort study of 172 newborns up to 4 days diagnosed with neonatal sepsis was carried out in Karaganda (Kazakhstan). The microbiological examination was used to identify a causative agent of bloodstream infection. ELISA was performed to determine the total anti-SARS-CoV-2 antibodies. Gestational age, mode of delivery, birth weight, C-reactive protein and procalcitonin levels, comorbidities, type of pathogen, duration of hospitalization and mother’s infection diseases were used for statistical analysis.

Results

Mortality in infants with neonatal sepsis was 22% (38/172). Anti-SARS-CoV-2 antibodies were detected in 68.3% of the newborns. Culture-negative ELBW infants have a 5.3-fold higher risk of death (p<0.001). Low gestational age and a shorter period of hospitalization were statistically associated with fatality. CRP is generally higher in deceased children (p=0.002). Necrotizing enterocolitis (p<0.001), pneumonia (p=0.009) and anemia (p=0.016) were significantly associated with negative outcome. And, 31.4% of the infants with sepsis had positive blood cultures. The leading cause of sepsis in newborns was CoNS – 57%.

Conclusion

During COVID-19 pandemic neonatal sepsis mortality was associated with low birth weight, gestational age, and comorbidities as in non-pandemic time. The relationship between COVID-19 in the mother and neonatal mortality was not found. However, anti-SARS-CoV-2 antibodies were detected in more than half of newborns.

Microbial Landscape and Antibiotic Susceptibility Dynamics of Skin and Soft Tissue Infections in Kazakhstan 2018–2020

Skin and soft tissue inflammatory diseases of bacterial origin occupy a significant part of hospitalizations to emergency departments. One of the most common causes of sepsis is soft tissue infection, which accounts for about a quarter of all nosocomial infections. The aim of this study was to determine the differences in microbial landscape and antibiotic susceptibility of soft tissue infection pathogens among adults and children during the period 2018–2020. We studied 110 samples of pus admitted to the Scientific Research laboratory of the Karaganda Medical University from 2018 to 2020. Each sample was studied using the standard and express methods. The antibiotic susceptibility was determined by using the diffuse disk method in accordance with the CLSI 2018 recommendations. As such, 50% of S. epidermidis strains in children and 30% in adults were methicillin resistant. Differences in the resistance of S. aureus strains in children and adults were insignificant. Thus, methicillin-resistant S. aureus (MRSA) was not detected in children, but in adults, on the other hand, their percentage was 12.5%. The third cause of infection in adults was E. coli (13.72%), among which 75% were multidrug resistant. A. baumanii was found in 4.9% of adult patients’ samples, of which 60% were multidrug resistant. The effectiveness of the most prescribed antibiotics decreased due to the isolated strain resistance.

Influence of Pathogen Type on Neonatal Sepsis Biomarkers

Understanding immunoregulation in newborns can help to determine the pathophysiology of neonatal sepsis and will contribute to improve the diagnosis, prognosis, and treatment and remains an urgent and unmet medical need to understand hyperinflammation or hypoinflammation associated with sepsis in newborns. This study included infants (up to 4 days old). The "sepsis" criteria was a positive blood culture. C-reactive protein demonstrates a strong dependence on the pathogen etiology. Therefore, its diagnostic odds ratio in Gram-positive bacteremia was 2.7 and the sensitivity was 45%, while Gram-negative was 15.0 and 81.8%, respectively. A neutrophil-lymphocyte ratio above 1 and thrombocytopenia below 50 ^∗ 10⁹ cells/L generally do not depend on the type of pathogen and have a specificity of 95%; however, the sensitivity of these markers is low. nCD64 demonstrated good analytical performance and was equally discriminated in both Gram (+) and Gram (-) cultures. The sensitivity was 87.5-89%, and the specificity was 65%. The HLA-DR and programmed cell death protein study found that activation-deactivation processes in systemic infection is different at points of application depending on the type of pathogen: Gram-positive infections showed various ways of activation of monocytes (by reducing suppressive signals) and lymphocytes (an increase in activation signals), and Gram-negative pathogens were most commonly involved in suppressing monocytic activation. Thus, the difference in the bacteremia model can partially explain the problems with the high variability of immunologic markers in neonatal sepsis.