Microbiological Tests Research Articles

B-071 Unraveling Histamine Intolerance: Exploring DAO Quantity, Elimination Ratios and Cofactor Influences

Abstract Background Non-allergic reactions to food, often triggered by biogenic amines like histamine, result in symptoms such as headache, rhinitis, respiratory issues, digestive complaints, and eczema. The symptomatic overlap between histamine intolerance (HIT) and allergies may contribute to potential underdiagnosis. Limited data impedes precise incidence determination, but estimates suggest 1-3% of the population is affected, with increasing cases anticipated as knowledge and diagnostic tools for HIT advance. Despite histamine's physiological importance, elevated levels pose health risks. HIT arises when ingested or internally released histamine surpasses rapid breakdown capacity. Studies link HIT to DAO deficiency and/or impaired DAO activity, often in subgroups with genetic, pathological, or pharmacological factors. DAO cofactor deficiencies like copper, zinc, vitamin C or vitamin B6 may exacerbate DAO impairment. The trial aimed to explore the relationship of histamine elimination, DAO quantity, and essential cofactors for DAO activity. Methods Serum samples from 40 patients underwent analysis for DAO quantity and histamine elimination ratio using Immundiagnostik AG test kits. ELISA quantification employed a sandwich technique with polyclonal antibodies against recombinant DAO. Low DAO levels (< 3 U/ml) indicated histamine intolerance, moderate levels (3 - 10 U/ml) suggested probability, and high levels (< 10 U/ml) initially ruled out intolerance. Histamine elimination efficiency was assessed by comparing spiked sample levels at 0 and 24 hours after incubation, gauging histamine breakdown mechanisms without directly measuring enzyme quantity. Histamine elimination > 40% indicated unlikely intolerance, 25 - 40% (moderate) suggested probability, and < 25% (poor) indicated likelihood. Additionally, vitamin B6 influence was explored using Immundiagnostik AG's microbiological ID-VIT Test system, spiking samples with DAO for supplementation. Six samples with varying B6 levels underwent investigation. Results The investigation revealed that DAO quantity and histamine elimination highlight the enzyme's pivotal role. Distinctions emerged in histamine intolerance classification, with more than 25% of the population showing reduced elimination in samples with moderate DAO levels (3-10 U/mL), and more than 10% showing reduced elimination in samples with high DAO levels (>10 U/mL), suggesting potential DAO inhibition contributing to impaired histamine breakdown. Analyses based on functional vitamin B6 levels demonstrated varying responses to DAO supplementation. Samples with high functional B6 levels (>20 µg/l) showed a 20% increase in elimination with DAO supplementation of 3 U/mL. In contrast, samples with lower B6 levels (<7 µg/l) exhibited minimal to no additional elimination, despite supplemental DAO at 6 U/mL. These findings underscore the nuanced interplay among DAO levels, histamine elimination, and the influence of vitamin B6, providing insights into factors impacting histamine metabolism across diverse patient profiles. Conclusions The data unveil a high potential for differential diagnosis, particularly in the realm of moderate to high DAO quantity, where the dependence on DAO inhibition yields a different classification of HIT probability. Analyzing DAO cofactors, such as vitamin B6, emerges as a valuable complementary tool for the diagnosis and treatment of HIT. These findings underscore the importance of considering DAO levels, their inhibition, and cofactors in a comprehensive approach to enhance the accuracy of HIT assessment and guide effective therapeutic interventions.

Clostridioides difficile infections: Update and therapeutic guidelines

Clostridioides difficile infection (CDI) represents a significant challenge due to its increasing incidence, severity, and treatment difficulty. Effective management requires a multifactorial approach that includes preventive strategies, prudent antibiotic use, and adapted therapeutic options. Ongoing research and innovation offer promising prospects for improving ICD management, making vigilance and informed practices essential among healthcare professionals. Two main complications of ICD are pseudomembranous colitis (PMC) and toxic megacolon. PMC involves severe colonic inflammation due to C.difficile toxins, leading to pseudomembrane formation. Diagnosis relies on clinical criteria, microbiological tests, and endoscopy. Toxic Megacolon is characterized by severe colonic dilation and systemic toxicity, requiring immediate medical intervention. ICD diagnosis combines clinical signs and microbiological tests. These tests include toxin tests, GDH antigen detection, PCR for toxin genes, and stool culture. Imaging techniques assess colonic inflammation and complications. Combined diagnostic criteria from the American Gastroenterological Association (AGA) and European guidelines emphasize integrating clinical and laboratory findings for accurate diagnosis. ICD treatment involves stopping the implicated antibiotics and starting specific antimicrobial therapy. Common treatments include mainly fidaxomicin and oral vancomycin. Fecal microbiota transplantation (TMF) is recommended for recurrent cases unresponsive to standard treatments. Bezlotoxumab, an antibody targeting C.difficile toxin B, is used to prevent recurrence in high-risk adults. ICD poses a major challenge due to its increasing incidence, severity, and difficulty in treatment. A multifactorial approach involving rigorous preventive strategies, prudent antibiotic management, and adapted therapeutic options is essential for controlling the infection. Ongoing research and innovations in treatment offer promising prospects for improving patient management. Healthcare professionals must remain vigilant and informed to ensure effective practices in combating this infection and utilizing available resources optimally.

Clinical Application of Metagenomic Next-Generation Sequencing in Sepsis Patients with Early Antibiotic Treatment.

This study aimed to evaluate the clinical utility of metagenomic next-generation sequencing (mNGS) in sepsis patients who received early empirical antibiotic treatment. A retrospective analysis was conducted on clinical data from sepsis patients diagnosed in the Emergency Intensive Care Unit (EICU) between April 2019 and May 2023. All patients underwent standard conventional microbiological testing. Patients were categorized into either the mNGS group or the control group based on whether they underwent mNGS tests. Baseline variables were matched using propensity scores. Out of 461 sepsis patients screened, 130 were included after propensity matching, with 65 patients in each group. Despite prior antibiotic treatment, 57 cases (87.69%) in the mNGS group had positive mNGS results, exceeding the culture detection rate (52.31%). Besides, a higher proportion of patients in the mNGS group experienced antibiotic adjustments compared to the control group (72.31% vs 53.85%). Mortality rates were also compared based on the duration of antibiotic exposure before mNGS sampling. Patients exposed to antibiotics for less than 24hours had a lower mortality rate compared to those exposed for over 8 days (22.22% vs 42.86%). COX multivariate analysis identified mNGS testing, underlying diseases, lymphocyte percentage, infection site (respiratory and bloodstream) as independent risk factors for mortality in sepsis patients. With increased antibiotic exposure time, the positive rate of culture testing significantly decreased (44.44% vs 59.52% vs 35.71%, P = 0.031), whereas the positive rate of mNGS remained stable (77.78% vs 88.10% vs 92.86%, P = 0.557). mNGS demonstrated less susceptibility to antibiotic exposure. Early mNGS detection positively impacted the prognosis of sepsis patients.

Microbiological Profile and Antimicrobial Susceptibility Pattern of Uropathogens Isolated From Pregnant Women Attending a Tertiary Care Hospital in Central India.

Urinary tract infections (UTIs) are more common in females than males, and during pregnancy, frequency is increased due to hormonal changes affecting the anatomy and physiology. If not treated on time, complications may develop in both the mother and fetus. This study aimed to analyze the microbiological (bacterial and yeast) profile of the isolated uropathogens and their antimicrobial susceptibility. Aseptically collected urine specimens were processed by the standard loop method. Identification of uropathogens was done by standard microbiological tests, and antimicrobial susceptibility was performed as per the Clinical and Laboratory Standards Institute (CLSI) guidelines. Out of 400 study participants, UTI was detected in 26.75% (107/400) of cases. Overall, Escherichia coli (42.99%, 46/107) was the most frequently isolated uropathogen followed by Candida species (20.56%, 22/107), whereas, among gram-positive bacteria, Enterococcus faecalis (7.47%, 8/107) was the commonest. Among Enterobacterales, extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC) production was observed in 19.35% (12/62, eight E. coli and four Klebsiella) and 6.45% (4/62, all E. coli) isolates, respectively. However, all the gram-negative organisms showed 100% (n=70) sensitivity to carbapenems. Among staphylococci, 50% (2/4) of isolates were methicillin-resistant, and high-level aminoglycoside resistance (HLAR) was observed in 75% (6/8) of Enterococcus faecalis isolates, but all were sensitive to vancomycin, linezolid, and nitrofurantoin. Among Candida species, non-albicans Candida (NAC) species (59%, 13/22) outweigh the number of Candida albicans (41%, 9/22), with Candida tropicalis (22.72%, 5/22) being the commonest NAC. All the Candida species were susceptible to voriconazole, whereas fluconazole resistance was observed in 31.81% (7/22) of Candida isolates, with a higher percentage in NAC species (22.72%, 5/22) than in Candida albicans (9.09%, 2/22). UTIs in pregnancy are caused by a spectrum of both gram-negative bacilli and gram-positive cocci. Moreover, there is a rise of both Candida albicans and NAC species as uropathogens, with the emergence of fluconazole resistance. There is an increased prevalence of asymptomatic bacteriuria in pregnancy, which necessitates the screening of pregnant females for UTI using culture and antimicrobial susceptibility testing.

A validated high-performance liquid chromatography-ultraviolet method for the determination of valproic acid derivatives in pharmaceutical formulations with a microbiological suitability evaluation

Valproic acid and its derivatives are common drugs used in the treatment of epilepsy, a result of CNS disorders. Because the molecular structure of valproic acid, as a fatty acid, does not contain any chromophore groups, its peak response demanded special conditions to be detected in HPLC, ensuring the best precision results. Still, the current approach illustrates simple, validated procedures for conduction. The conducted chromatographic system consists of the BDS Hypersil C8, 150 × 4.6 mm, 5 µm column using a mobile phase of acetonitrile: phosphate buffer (4:6) at a detection wavelength of 215 nm at room temperature. A full method validation study was conducted and approved to ensure precise, repeatable, and accurate results by implementing system suitability parameters. In microbiological terms, a suitability test is used to validate microbiological testing methods, ensuring their efficacy despite potential interference from antimicrobial properties in the tested materials. The HPLC-UV developed and validated analytical method was evaluated, and it was found to be sensitive for use in the detection of low concentrations of methylparaben, propylparaben, and valproate with an optimum run time of six minutes. limit of detection (LODs) were statistically estimated and found to be 2.27 µg/mL, 39.77 ng/mL, and 1.84 µg/mL for methylparaben, propylparaben, and valproate, respectively. Additionally, the method demonstrated a high recovery of methylparaben, propylparaben, and valproate with an excellent closed-accuracy range (98.84% - 101.34%). An excellent regression coefficient (r) of 0.99924, 0.99998, and 0.99997 for methylparaben, valproate, and propylparaben, respectively, was achieved. Assay determination of various pharmaceutical dosage forms in the local market was implemented, yielding admirable results.

The foundation for the microbiology laboratory's essential role in diagnostic stewardship: an ASM Laboratory Practices Subcommittee report.

Diagnostic stewardship (DxS) has gained traction in recent years as a cross-disciplinary method to improve the quality of patient care while appropriately managing resources within the healthcare system. Clinical microbiology laboratorians have been highly engaged in DxS efforts to guide best practices with conventional microbiology tests and more recently with molecular infectious disease diagnostics. Laboratories can experience resistance to their role in DxS, especially when the clinical benefits, motivations for interventions, and underlying regulatory requirements are not clearly conveyed to stakeholders. Clinical laboratories must not only ensure ethical practices but also meet obligatory requirements to steward tests responsibly. In this review, we aim to support clinical microbiology laboratorians by providing the background and resources that demonstrate the laboratory's essential role in DxS. The heart of this review is to collate regulatory and accreditation requirements that, in essence, mandate DxS practices as a long-standing, core element of high-quality laboratory testing to deliver the best possible patient care. While examples of the clinical impact of DxS are plentiful in the literature, here, we focus on the operational and regulatory justification for the laboratory's role in stewardship activities.

Comparing the diagnostic value of targeted with metagenomic next-generation sequencing in immunocompromised patients with lower respiratory tract infection

BackgroundAccurate identification of the etiology of lower respiratory tract infections (LRTI) is crucial, particularly for immunocompromised patients with more complex etiologies. The advent of next-generation sequencing (NGS) has enhanced the effectiveness of pathogen detection. However, assessments of the clinical diagnostic value of targeted NGS (tNGS) in immunocompromised patients with LRTI are limited.MethodsTo evaluate the diagnostic value of tNGS in immunocompromised patients with LRTI, a total of 88 patients, of whom 54 were immunocompromised, were enrolled. These patients underwent tNGS testing of bronchoalveolar lavage fluid (BALF). Results from both metagenomic next-generation sequencing (mNGS) and conventional microbiological tests (CMT) were also available for all participants. The performance of tNGS was assessed by comparing its findings against mNGS, CMT, and the clinical composite diagnosis.ResultsIn the cohort of 88 patients, tNGS showed comparable diagnostic value to mNGS and was significantly superior to CMT. Compared to CMT and composite reference standard, tNGS showed sensitivity of 94.55% and 90.48%, respectively. In immunocompromised patients, despite a more diverse pathogen variety, tNGS maintained similar sensitivity to mNGS and outperformed CMT. tNGS positively influenced etiologic diagnosis and antibiotic decision-making in 72.72% of cases, leading to a change in antibiotic regimen in 17.05% of cases. We also compared the detection of microbial nucleic acids by tNGS with mNGS and found that tNGS could identify 87.99% of the microbial nucleic acids identified by mNGS.ConclusionIn summary, our study demonstrated that tNGS offers promising clinical diagnostic accuracy in immunocompromised patients, as evidenced by its favorable comparison with CMT, the composite reference standard, and mNGS.

Serological study of Crimean – Congo haemorrhagic fever in Sheep in Thi – Qar province

Crimean Congo hemorrhagic fever virus (CCHFV) causes a lethal tick – borne zoonotic disease with severe clinical manifestation in humans but does not produce symptomatic disease in wild or domestic animals. It is endemic in a large region of the word. One of the main indicators that the disease is endemic in a region is the presence of antibodies specific to CCHFV in animal populations. The factors contributing to differential outcomes of infection between species are not understood. Serological studies have shown sheep are important to the survival of CCHFV in nature. Nevertheless, need for more studies on this subject in Iraq. Blood samples were taken from 200 sheep of different sex, variable age and physiological status. Only 100 samples used for physiological testes while 186 used for Microbiological test (ELISA) test. The present study was appeared a high level about (144)78.53% of positive carrier sheep while negative samples (42)21.46% in Thi – Qar province which include different regions such as Al-eakihah , Al- rifai and Al- garma region which recorded about 92.85% , 90% and 90 % respectively comparative with another region of thi qar province that appear low level of infected such as Al-fadhliya , Al-tar and Al- manar which recorded about 75%, 50% and 60.71% respectively. The current study focused on and attempted to connect the different physiological states, sex and age with infected animals. The male sex appears ahigh level of infected about 83.92% comparative with female was appeared low level of infected by CCHF virus about 74.61%, while recorded high infected in non – pregnant about 75% comparative with pregnant about 73,80 . Also, the present study was showed ahigh level of infected in age from 5 to nine years about 82.4% comparative with another age ranges which appeared about 71.11, 78.50 %.

Cefadroxil photodegradation processes sensitized by natural pigments: mechanistic aspects and impact on the antimicrobial function.

Cefadroxil is a widely used antibiotic with a low elimination efficiency in wastewater treatments plants, so it represents a contaminants of emerging concern that should be removed. The photosensitization process that involves natural pigments and visible sunlight can be offered as an environmentally friendly alternative to be considered for Cefadroxil degradation. In this investigation, we carried out a mechanistic and kinetic approach to Cefadroxil photodegradation sensitized by Riboflavin and Humic Acid, in individual and combined processes. Our experiments indicate that Cefadroxil is able to interact with the excited states of Riboflavin as well as with the photogenerated reactive oxygen species, with an important contribution of singlet oxygen. The antibiotic was less sensitive to the photodegradation in the presence of Humic Acids and in the mixture of Riboflavin and Humic Acids. Self-sensitization processes and internal filter effects are proposed as possible explanations for the observed phenomenon. The reaction between Cefadroxil and singlet oxygen showed a dependence with the pH of the medium, the photodegradation kinetic constants are greater at alkaline pH compared to neutral pH. The reaction is favored when the anionic species of the antibiotic is present. Microbiological tests on S. aureus indicated that the antibiotic reduce its antimicrobial activity as a consequence of the photooxidative process mediated by singlet oxygen. We believe that the results are relevant since, the sensitized photodegradation process could lead to the oxidation of Cefadroxil and to the progressive loss of its antimicrobial function, this fact could contribute to the decrease in the generation of bacterial multi-resistance to antibiotics in the environment.

Advantages of metagenomic next-generation sequencing in the management of ANCA-associated vasculitis patients with suspected pulmonary infection as a rule-out tool

ObjectivePulmonary infection is one of the leading causes of death in patients with ANCA-associated vasculitis (AAV). It is sometimes difficult to differentiate pulmonary infection from pulmonary involvement of vasculitis in AAV patients. Fiberoptic bronchoscopy and bronchoalveolar lavage fluid (BALF) assays are useful diagnostic methods. In addition to conventional microbiological tests (CMTs), metagenomic next-generation sequencing (mNGS) facilitates rapid and sensitive detection of various pathogens. The current study aimed to evaluate the advantages of additional BALF mNGS in the management of pulmonary infection in AAV patients.Methods27 patients with active AAV and suspected pulmonary infection whose BALF samples were tested by mNGS and CMTs and 17 active AAV patients whose BALF were tested by CMTs alone were retrospectively recruited. The results of microbiological tests, and adjustments of treatment following BALF mNGS, were described. The durations of antimicrobial treatment and in-hospital mortality in patients were compared.ResultsAmong the 27 patients whose BALF samples were tested by mNGS, 25.9% of patients did not have evidence of pathogenic microorganism in their BALF samples, 55.6% had polymicrobial infections, including bacteria, fungi and viruses. Of these 27 patients, 40.7% did not have evidence of pathogenic microorganism in their BALF or serum samples according to CMTs. Patients in the BALF mNGS/CMT group received a significantly shorter duration of antibacterial and total antimicrobial treatment than patients in the CMT alone group (17.3 ± 14.7 vs. 27.9 ± 19.0 days, P = 0.044; 18.9 ± 15.0 vs. 29.5 ± 17.7 days, P = 0.040, respectively). Fewer patients in the BALF mNGS/CMT group died than in the CMT alone group (4/27 vs. 7/17, P = 0.049).ConclusionCompared with CMT alone, additional mNGS tests may shorten the duration of antimicrobial treatment and possibly decrease death from severe infection by providing precise and quick diagnosis of infection.

Characterization of Laboratory-Confirmed Creutzfeldt-Jakob Disease From 3 Ontario Tertiary Care Centers Between 2012 and 2022: A Retrospective Cohort Study.

Globally, Creutzfeldt-Jakob disease (CJD) affects one in one million people annually, but there is a paucity of recent Canadian data. This study summarizes epidemiology trends and diagnostic timelines of laboratory-confirmed CJD cases in three tertiary Ontario hospitals. Using laboratory information systems, we identified 30 patients with a laboratory-confirmed CJD diagnosis between 2012 and 2022 at three major tertiary hospitals in Ontario. Retrospective chart reviews were then completed. Patients had a mean of 2.2 hospital visits (SD, 1.2) prior to being admitted for testing. The most common symptom presentations included loss of coordination (63.3%), behavioral changes (60%), progressive mobility loss (53.4%), memory loss (50.0%), and involuntary movements (50.0%). Magnetic resonance imaging findings showed potential CJD in 76.7% of cases, and 56.7% exhibited periodic sharp wave complexes characteristic of CJD on electroencephalogram. The mean duration from symptom onset to microbiologic testing was 91 days (SD, 90.7). End-point quaking-induced conversion (EP-QuIC) testing of cerebrospinal fluid was positive in 90.0% of patients, while 83.3% tested positive for 14-3-3 on enzyme-linked immunosorbent assay. Elevated cerebrospinal fluid 14-3-3 levels significantly correlated with shorter duration from symptom onset to death (R 2 = 0.71, F = 19.55, P = .0022). Post-diagnosis, 46.7% of patients were discharged home, 16.6% were transferred to external palliative care or hospice facilities, and 36.7% died during admission. The mean time from symptom onset to death was 121 days (SD, 120.7), and from diagnosis to death 35 days (SD, 83.9). This study highlights the importance of early CJD consideration and laboratory testing when appropriate neurologic symptoms are present.

Evaluation of Different Lactic Acid Bacteria as Starter Cultures for Nono—A West African Fermented Dairy Product

Nono is a traditional cultured dairy product consumed across West Africa. In this study, five cultures isolated from Nigerian-produced nono and three purified lactic acid bacteria from the USDA-NRRL were examined for use in preparing nono starter cultures. Isolated cultures were characterized using microbiological and biochemical tests, including 16s rDNA sequencing to identify the genotype. Each isolated strain was cultured and inoculated into UHT milk (1% v/v) and allowed to ferment for 24 h at 25 °C. Fermented products were evaluated for pH, moisture content, water activity, and viscosity, and their descriptive sensory properties were noted. The isolate that resulted in sensory properties most similar to traditional nono was then used as the primary strain for subsequent starter culture blends made with the NRRL cultures. These blends were used for the fermentation of nono and compared with commercial nono samples. Isolates obtained from nono were as follows: Lactobacillus fermentum, Lactobacillus paracasei, and, surprisingly, Lactobacillus rhamnosus, which has not been previously reported as a part of the nono microflora. There was no significant difference in the physical parameters of nono made from the individual indigenous isolates and a similar pattern was observed for the organisms from NRRL, except that their total titratable acidity and viscosities were significantly (p < 0.05) higher than those of the indigenous organisms. Compounded starter made with L. rhamnosus and NRRL cultures was then used to make nono that showed significantly (p < 0.05) different pH and viscosity values than commercially purchased nono, while sensory evaluation showed that nono made from the new starter culture had a high overall consumer acceptance score.

Pathogen detection by targeted next-generation sequencing test in adult hematological malignancies patients with suspected infections.

Infections in patients with hematological malignancies (HM) are a significant cause of morbidity and mortality. Timely and effective empirical anti-infective treatment can reduce the infection-related mortality rate. Targeted next-generation sequencing (tNGS) offers a rapid diagnostic approach for identifying diverse pathogens in these patients. However, relevant research is still limited to adult patients with HM. We conducted a retrospective analysis of adult HM patients admitted to our hospital from March 2023 to September 2023, focusing on their clinical characteristics and the results of both tNGS and conventional microbiological tests (CMTs). We evaluated the performance of tNGS and CMTs in pathogenic diagnosis and described the distribution characteristics of pathogens in adult HM patients with infections. The study included 209 samples collected from 137 patients. Results showed that the overall pathogen detection rate differed significantly between tNGS and CMTs (60.3% vs. 24.4%, p < 0.001). The sensitivity (69.7% vs. 35.9%), negative predictive value (NPV) (48.2% vs. 42.4%), and accuracy (66.5% vs. 56.5%) of pathogen detection were notably superior with tNGS compared to CMTs. Among the 142 samples with clinically diagnosed infections, tNGS combined with CMTs identified a definite or probable microbial etiology in 114 samples (80.3%). Of the 36 samples with concordant positive results from both tNGS and CMTs, 72.2% (26/36) exhibited full or partial agreement. Our study further showed the highest detection rate for viral infections (57.0%), predominantly for Epstein-Barr virus (DNA-V, 18.3%). Followed by bacterial infections (46.5%), the detection rate of Gram-negative bacteria (G+, 35.9%) was higher than that of Gram-positive bacteria (G-, 21.8%) in this study. Klebsiella pneumoniae (G-, 12.7%) had the highest detection rate among these emerging bacteria, followed by Pseudomonas aeruginosa (G-, 10.6%) and Enterococcus faecium (G+, 7.7%). Bacterial-viral coinfections were the most common type of mixed infection (35.5%). In conclusion, tNGS outperforms CMTs in both sensitivity and pathogen spectrum. Therefore, it can serve as an adjunct to CMTs to facilitate the precise adjustment of anti-infective regimens for adult HM patients. Our findings establish a basis for formulating empirical anti-infective therapy strategies tailored to the pathogen distribution in this patient population.

Silicone allergy manifestation in pediatric ventriculoperitoneal shunting: navigating diagnostic challenges and customizing therapeutic approaches. Illustrative case.

A silicone allergy can significantly impact the efficacy of ventriculoperitoneal shunt devices used in hydrocephalus treatment. Its clinical presentation often resembles infectious ventriculitis, characterized by altered cerebrospinal fluid (CSF) parameters, including low glucose levels, elevated protein concentrations, and increased white blood cell counts predominantly comprising eosinophils. The authors report the case of an 18-month-old male who experienced recurrent shunt malfunction linked to CSF changes indicative of infectious ventriculitis. The patient underwent surgeries for suspected infection management. Notably, he exhibited increased eosinophil counts in both blood and CSF, as well as the development of neoformation tissue. This, along with the absence of microbial infection, indicated silicone hypersensitivity. While navigating medical device scarcity, innovative methods were employed to secure a silicone-free valve, markedly improving the patient's clinical outcome. Clinicians must be vigilant for silicone allergy in patients with ventriculoperitoneal shunts, particularly when elevated serum eosinophil counts and negative microbiological tests are present. This rare condition demands a multidisciplinary approach for timely diagnosis and management to reduce morbidity, unnecessary surgeries, and healthcare costs. The limited availability of non-silicone-based shunts further complicates management. This case emphasizes the need for considering silicone allergy in differential diagnoses, especially in pediatric patients. https://thejns.org/doi/10.3171/CASE2474.

Clinical Diagnostic Value and Accuracy of Microbiological Testing for Pulmonary Aspergillosis Infection

Objective: To analyze the clinical diagnostic value and accuracy of microbiological testing for pulmonary aspergillosis infection.Methods: Sixty patients suspected of having pulmonary aspergillosis infection from January 2023 to June 2024 were selected. All selected patients underwent sputum culture test, galactomannan test (GM test), and 1,3-β-D-glucose (BDG) test (referred to as G test). Pathological histology examination was used as the gold standard to evaluate the diagnostic value and accuracy of sputum culture test, GM test, and G test in pulmonary aspergillosis infection. Results: In this study, histopathological examination of 60 patients showed 35 positive cases and 25 negative cases of pulmonary aspergillosis infection. The sputum culture test results showed that there were 34 positive cases, 26 negative cases, 7 false positives, and 6 false negatives of pulmonary aspergillosis infection. The GM test results showed that there were 34 positive cases, 26 negative cases, 3 false positives, and 2 false negatives of pulmonary aspergillosis infection. The G test results showed that there were 34 positive cases, 26 negative cases, 8 false positives, and 7 false negatives of pulmonary aspergillosis infection. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the GM test were significantly higher than those of the sputum culture test and G test (P&lt;0.05). Conclusion: The diagnostic value of the GM test in pulmonary aspergillosis infection is higher than the sputum culture test and G test, and it can be widely used.

Identifying optimal serum 1,3-β-D-Glucan cut-off for diagnosing Pneumocystis Jirovecii Pneumonia in non-HIV patients in the intensive care unit

BackgroundSerum (1,3)-β-D-glucan (BDG) detection for diagnosis of Pneumocystis jirovecii pneumonia (PJP) in non-human immunodeficiency virus (HIV) immunocompromised patients lacks intensive care unit (ICU)-specific data. We aimed to assess its performance and determine the optimal cutoff for PJP in ICU population.MethodsThis retrospective study included critically ill non-HIV immunocompromised patients admitted to a medical ICU with suspected pneumonia, undergoing simultaneous microbiological testing for P. jirovecii on lower respiratory tract specimens and serum BDG. Confounders affecting BDG positivity were explored by multivariable logistic regression. Optimal cut-offs were derived from Youden’s index for the entire cohort and subgroups stratified by confounders. Diagnostic performance of serum BDG was estimated at different cutoffs.ResultsOf 400 patients included, 42% were diagnosed with PJP and 58.3% had positive serum BDG. Serum BDG’s area under the receiver operating characteristic curve was 0.90 (0.87–0.93). At manufacturer’s 150 pg/ml cut-off, serum BDG had high sensitivity and negative predictive value (94%), but low specificity and positive predictive value (67%). Confounders associated with a positive serum BDG in PJP diagnosis included IVIG infusion within 3 days (odds ratio [OR] 9.24; 95% confidence interval [CI] 4.09–20.88, p < 0.001), other invasive fungal infections (OR 4.46; 95% CI 2.10–9.49, p < 0.001) and gram-negative bacteremia (OR 29.02; 95% CI 9.03–93.23, p < 0.001). The application of optimal BDG cut-off values determined by Youden’s index (252 pg/ml, 390 pg/ml, and 202 pg/ml) specific for all patients and subgroups with or without confounders improved the specificity (79%, 74%, and 88%) and corresponding PPV (75%, 65%, and 85%), while maintaining reasonable sensitivity and NPV.ConclusionsTailoring serum BDG cutoff specific to PJP and incorporating consideration of confounders could enhance serum BDG’s diagnostic performance in the ICU settings.

Extracellular vesicle miRNome during subclinical mastitis in dairy cows

Bovine mastitis is one of the main inflammatory diseases that can affect the udder during lactation. Somatic cell counts and sometimes microbiological tests are routinely adopted during monitoring diagnostics in dairy herds. However, subclinical mastitis is challenging to identify, reducing the possibility of early treatments. The main aim of this study was to investigate the miRNome profile of extracellular vesicles isolated from milk as potential biomarkers of subclinical mastitis. Milk samples were collected from a total of 60 dairy cows during routine monitoring tests. Small RNA sequencing technology was applied to extracellular vesicles of milk samples collected from cows classified according to the somatic cell count to identify differences in the miRNome between mastitic and healthy cows. A total of 1997 miRNAs were differentially expressed between both groups. Among them, 68 miRNAs whose FDRs were < 0.05 were mostly downregulated, with only one upregulated miRNA (i.e., miR-361). Functional analysis revealed that miR-455-3p, miR-503-3p, miR-1301-3p and miR-361-5p are involved in the regulation of several biological processes related to mastitis, including immune system-related processes. This study suggests the involvement of extracellular vesicle-derived miRNAs in the regulation of mastitis. Moreover, these findings provide evidence that miRNAs from milk extracellular vesicles can be used to identify biomarkers of mastitis. However, further studies must be conducted to validate these miRNAs, especially for subclinical diagnosis.

Effects of Plant Meristem-Cell-Based Cosmetics on Menopausal Skin: Clinical Data and Mechanisms.

A randomised open clinical/laboratory study was performed to evaluate the safety and cosmetic efficacy of facial cosmetics for females during the menopausal period. The cosmetics contain active ingredients of meristem cells derived from the medicinal plants Leontopodium alpinum, Buddeleja davidii, Centella asiatica, and Echinacea angustifolia. Recently, the major bioactive molecules of these medicinal plants (leontopodic acid, verbascoside, asiaticoside, and echinacoside, respectively) have been thoroughly evaluated in vitro for molecular pathways and cellular mechanisms and their preventive/curative effects on human skin cells exposed to factors promoting premature skin ageing and cellular senescence. Nevertheless, clinical data on their safety/efficacy to ageing human skin are scarce. This clinical study enrolled 104 Caucasian females in pre-menopause, menopause, or post-menopause periods. They applied cosmetic serums daily for 1 month. Questionnaires and instrumental and biochemical methods were used to assess dermatological/ophthalmological safety and cosmetic efficacy through changes of the skin physiology markers characteristic of ageing/menopause (elasticity, barrier functions, moisture, sebum, ultrasonic properties, and collagen content and structure). Quantitative microbiological tests were carried out for skin microbiota fluctuations. Data showed that the cosmetics were safe, and they shifted the skin physiology parameters to a younger biological age, enhanced collagen synthesis, inhibited lipid peroxidation, and favoured normal microbiota.

Metagenomic next generation sequencing of plasma RNA for diagnosis of unexplained, acute febrile illness in Uganda.

Metagenomic next generation metagenomic sequencing (mNGS) has proven to be a useful tool in the diagnosis and identification of novel human pathogens and pathogens not identified on routine clinical microbiologic tests. In this study, we applied mNGS to characterize plasma RNA isolated from 42 study participants with unexplained acute febrile illness (AFI) admitted to tertiary referral hospitals in Mubende and Arua, Uganda. Study participants were selected based on clinical criteria suggestive of viral infection (i.e., thrombocytopenia, leukopenia). The study population had a median age of 28 years (IQR:24 to 38.5) and median platelet count of 114 x103 cells/mm3 (IQR:66,500 to 189,800). An average of 25 million 100 bp reads were generated per sample. We identified strong signals from diverse virus, bacteria, fungi, or parasites in 10 (23.8%) of the study participants. These included well recognized pathogens like Helicobacter pylori, human herpes virus-8, Plasmodium falciparum, Neisseria gonorrhoeae, and Rickettsia conorii. We further confirmed Rickettsia conorii infection, the cause of Mediterranean Spotted Fever (MSF), using PCR assays and Sanger sequencing. mNGS was a useful addition for detection of otherwise undetected pathogens and well-recognized non-pathogens. This is the first report to describe the molecular confirmation of a hospitalized case of MSF in sub-Saharan Africa (SSA). Further studies are needed to determine the utility of mNGS for disease surveillance in similar settings.

Atypical bacteria in pediatric sickle cell patients with acute chest syndrome

Abstract The purpose of this study was to quantify the frequency of Mycoplasma pneumoniae or Chlamydia pneumoniae in a large contemporary real-world data set. This was a retrospective database analysis utilizing data collected from the TriNetX Global Collaborative Network, which provided access to electronic medical records for patients from 78 different healthcare organizations. Data were collected using ICD-10 codes and laboratory test order codes from TriNetX. Inclusion criteria are patients less than or equal to 18 years old with SCD with an ICD-10 code for ACS or pneumonia. Patients were included in the primary outcome analysis if they had a laboratory code for a rapid diagnostic test for M. pneumoniae and/or C. pneumoniae performed by either nasal swab or respiratory culture. There were 6762 pediatric sickle cell patients with an ICD-10 code for ACS or pneumonia identified. Of these patients, only 16.3% were tested for M. pneumoniae and 17.1% were tested for C. pneumoniae. The patients who were tested for these atypical organisms were further investigated for positivity on rapid diagnostic testing, and the positivity rate in these patients was 1.1% for M. pneumoniae and less than or equal to 0.87% for C. pneumoniae. Pediatric patients with ACS who were tested for M. pnuemoniae and C. pnuemoniae had low rates of positivity for these organisms. Most of these patients did not have recorded microbiologic testing, showing evidence of a large underutilization of diagnostic tools available that could assist with de-escalation of antibiotics.