Antigens Tested Research Articles

Various Diagnostic Methods for <i>Helicobacter pylori</i> Infection

<i>Helicobacter pylori</i> (<i>H. pylori</i>) is a bacterium that colonizes the human stomach, leading to various gastrointestinal diseases including gastritis, peptic ulcers, and gastric cancer. There is no gold standard test that relies entirely on one method in <i>H. pylori</i> diagnosis. We must be aware of the pros and cons of various testing methods to perform an appropriate test according to the situation. Accurate diagnosis and eradication therapy are essential for disease management. Diagnostic methods include invasive techniques like tissue biopsy and rapid urease test, as well as non-invasive tests such as urea breath test, serology test, and stool antigen test. Each method has its advantages and limitations, requiring careful consideration in clinical practice. Understanding these diagnostic tools is crucial for effective <i>H. pylori</i> management and prevention of associated complications.

Comparative analysis of tuberculin and defined antigen skin tests for detection of bovine tuberculosis in buffaloes (Bubalus bubalis) in Haryana state, India

BackgroundBovine tuberculosis (bTB) is a chronic disease that results from infection with any member of the Mycobacterium tuberculosis complex. Infected animals are typically diagnosed with tuberculin-based intradermal skin tests according to World Organization of Animal Health which are presently in use. However, tuberculin is not suitable for use in BCG-vaccinated animals due to a high rate of false-positive reactions. Peptide-based defined skin test (DST) antigens have been identified using antigens (ESAT-6, CFP-10 and Rv3615c) which are absent from BCG, but their performance in buffaloes remains unknown. To assess the comparative performance of DST with the tuberculin-based single intradermal test (SIT) and the single intradermal comparative cervical test (SICCT), we screened 543 female buffaloes from 49 organized dairy farms in two districts of Haryana state in India.ResultsWe found that 37 (7%), 4 (1%) and 18 (3%) buffaloes were reactors with the SIT, SICCT and DST tests, respectively. Of the 37 SIT reactors, four were positive with SICCT and 12 were positive with the DST. The results show that none of the animals tested positive with all three tests, and 6 DST positive animals were SIT negative. Together, a total of 43 animals were reactors with SIT, DST, or both, and the two assays showed moderate agreement (Cohen’s Kappa 0.41; 95% Confidence Interval (CI): 0.23, 0.59). In contrast, only slight agreement (Cohen’s Kappa 0.18; 95% CI: 0.02, 0.34) was observed between SIT and SICCT. Using a Bayesian latent class model, we estimated test specificities of 96.5% (95% CI, 92–99%), 99.7% (95% CI: 98–100%) and 99.0% (95% CI: 97–100%) for SIT, SICCT and DST, respectively, but considerably lower sensitivities of 58% (95% CI: 35–87%), 9% (95% CI: 3–21%), and 34% (95% CI: 18–55%) albeit with broad and overlapping credible intervals.ConclusionTaken together, our investigation suggests that DST has a test specificity comparable with SICCT, and sensitivity intermediate between SIT and SICCT for the identification of buffaloes suspected of tuberculosis. Our study highlights an urgent need for future well-powered trials with detailed necropsy, with immunological and microbiological profiling of reactor and non-reactor animals to better define the underlying factors for the large observed discrepancies in assay performance, particularly between SIT and SICCT.

Comparison of Two SARS-CoV-2 Rapid Antigen Test

The Coronavirus Disease 2019 (COVID-19) pandemic continues to spread worldwide. A quick, simple, and accurate test to diagnose COVID-19 is essential for this situation. This study aims to evaluate and compare the rapid antigen examination of SARS-CoV-2 with Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) in detecting SARS-CoV-2. A retrospective study with a cross-sectional approach using medical record data from suspected, controlled, and confirmed COVID-19 patients whose samples were taken simultaneously for rapid antigen examination of SARS-CoV-2 (SD-Biosensor and Lungene) and RT-PCR at Labuang Baji Hospital, Makassar from September 2020-September 2021. Each instrument's sensitivity, specificity, negative predictive value, and positive predictive value were analyzed with the Receiver Operating Characteristics (ROC) curve method. This study obtained data from 312 rapid antigen tests for SARS-CoV-2, divided into two categories, 98 using Lungene and 214 using SD-Biosensor. Rapid antigen Lungene had a sensitivity of 71.4%, specificity of 71.4%, an accuracy of 71.4%, and a 31 reactive result in CT value. The SD-Biosensor Rapid antigen had a sensitivity of 62.6%, a specificity of 99.1%, an accuracy of 82.2%, and a 26 reactive result in CT value. In summary, the sensitivity of rapid antigen Lungene is higher than SD-Biosensor. Specificity and accuracy of rapid antigen SD-Biosensor higher than Lungene. Rapid test antigen SARS-CoV-2 has the potential to be a screening test for COVID-19 as long as the sampling time is right.

Flexible and cost-effective genomic surveillance of P. falciparum malaria with targeted nanopore sequencing

Genomic surveillance of Plasmodium falciparum malaria can provide policy-relevant information about antimalarial drug resistance, diagnostic test failure, and the evolution of vaccine targets. Yet the large and low complexity genome of P. falciparum complicates the development of genomic methods, while resource constraints in malaria endemic regions can limit their deployment. Here, we demonstrate an approach for targeted nanopore sequencing of P. falciparum from dried blood spots (DBS) that enables cost-effective genomic surveillance of malaria in low-resource settings. We release software that facilitates flexible design of amplicon sequencing panels and use this software to design two target panels for P. falciparum. The panels generate 3–4 kbp reads for eight and sixteen targets respectively, covering key drug-resistance associated genes, diagnostic test antigens, polymorphic markers and the vaccine target csp. We validate our approach on mock and field samples, demonstrating robust sequencing coverage, accurate variant calls within coding sequences, the ability to explore P. falciparum within-sample diversity and to detect deletions underlying rapid diagnostic test failure.

Diversity and antigenic potentials of Mycoplasmopsis bovis secreted and outer membrane proteins within a core genome of strains isolated from North American bison and cattle.

Mycoplasmopsis bovis is a worldwide economically important pathogen of cattle that can cause or indirectly contribute to bovine respiratory disease. M. bovis is also a primary etiological agent of respiratory disease in bison with high mortality rates. A major challenge in the development of an efficacious M. bovis vaccine is the design of antigens that contain both MHC-1 and MHC-2 T-cell epitopes, and that account for population level diversity within the species. Publicly available genomes and sequence read archive libraries of 381M. bovis strains isolated from cattle (n=202) and bison (n=179) in North America were used to identify a core genome of 575 genes, including 38 that encode either known or predicted secreted or outer membrane proteins. The antigenic potentials of the proteins were characterized by the presence and strength of their T-cell epitopes, and their protein variant diversity at the population-level. The proteins had surprisingly low diversity and varying predictive levels of T-cell antigenicity. These results provide a reference for the selection or design of antigens for vaccine testing against strains infecting North American cattle and bison.

Efficacy of Bismuth Therapy in Eradicating Helicobacter pylori in Children-Data From the RENIHp Registry.

To evaluate the efficacy of colloidal bismuth subcitrate (CBS) therapy for the eradication of H. pylori in patients from a national pediatric registry of H. pylori infection. The Spanish Registry of Children with H. pylori Infection (RENIHp) is a national, multi-center, prospective, non-interventional registry that includes children aged 5-18 years with H. pylori infection diagnosed by endoscopy. All patients in the registry who were treated with CBS between the period 2020 and 2023 were included in this study. The primary outcome was the eradication rate, which was assessed using a 13C-urea breath test or monoclonal antigen in the stool 6-8 weeks post-treatment. The registry included 682 patients, 38 (5.6%) of whom underwent treatment with CBS. Fifty percent (19/38) of patients had previously undergone unsuccessful eradication treatment. In 78.9% (30/38) of patients, treatment was guided by an antibiotic sensitivity test. In the remaining patients, an empirical approach was employed. The CBS therapies used were as follows: quadruple therapy with proton pump inhibitors (PPIs), CBS, amoxicillin, and metronidazole (MET) [18/38 (47.3%)]; quadruple therapy with PPIs, CBS, tetracycline, and MET [13/38 (34.2%)]; and other therapies [7/38 (18.4%)]. Thirty-two patients (84.2%) treated with CBS were followed-up with eradication monitoring. The overall eradication rate in patients treated with CBS was 93.8% (30/32, [95% CI: 85.4%-100%]), whereas it was 86.7% in patients in the registry who were not on CBS treatment (430/496, [95% CI: 83.3%-89.5%], p = 0.208). In the six patients with dual resistance to clarithromycin (CLA) and MET who were treated with quadruple therapy with CBS, the eradication rate was 100% (n = 6/6, [95% CI: 61.0%-100%]). CBS therapies in our registry, although only used in selected cases and at lower than recommended levels, were very effective and showed an eradication rate of > 90%.

Protocolo diagnóstico, tratamiento y seguimiento de la infección por Helicobacter pylori recurrente/refractaria

The diagnostic tests for H. pylori detection are classified as non-invasive (C13-urea breath test, serology, and stool antigen test) and invasive (endoscopic study). The choice of the ideal technique will depend on the need to assess the gastric mucosa. The breath test is the non-invasive technique of choice in adult patients. Treatment will not be necessary in all patients in whom H. pylori infection is detected; it will only be necessary in certain situations. Treatment regimens may vary, but quadruple therapy (3 antibiotics or 2 antibiotics plus bismuth) is currently recommended, as well as proton-pump inhibitors in long regimens of 10 or 14 days. Treatment of recurrent or refractory H. pylori infection can be a clinical challenge. It is essential to adapt the protocol to each patient's clinical situation, taking into account antibiotic resistance and other individual factors.

Experimental infection of goats with Mycobacterium microti induces subclinical pulmonary tuberculosis and mild responses to tuberculin skin tests

Mycobacterium microti is a member of the Mycobacterium tuberculosis complex that seldom causes disease in livestock and humans. This study evaluated the effects on immunodiagnosis and the pathological findings in goats after experimental exposure by different routes and doses to M. microti. In a first experiment goats were challenged orally (PO, n = 7) or intranasally (IN, n = 7) with 104 CFU. In a second experiment, the endobronchial route was assessed, with a low dose of 102 CFU (EB-LD, n = 7) and a high dose of 105 CFU (EB-HD, n = 7) as well as the subcutaneous route (SC, n = 5). Temperature, body weight, clinical signs and immunological responses were monitored. Pathological evaluation was carried out and samples were processed for mycobacterial detection. Resultsdemonstrated the induction of a subclinical pulmonary infection in all the EB-HD challenged animals. Infection was also confirmed in one animal of the SC group, but not in the EB-LD, PO or IN groups. Two animals belonging to the EB-HD and SC groups, respectively, showed positive results to the single intradermal tuberculin test, and another two animals of the EB-HD and EB-LD groups showed doubtful (inconclusive) results, indicating that M. microti can induce mild responses to tuberculin skin testing. No positive results were observed when defined antigens absent in M. microti (ESAT-6 and CPF-10) were used.Our results indicate that animals exposed to M. microti can yield positive results to the skin tests currently performed in livestock tuberculosis eradication campaigns and reinforce the need to use specific antigens in antemortem tests to avoid interference with M. bovis/M. caprae diagnosis.

Correlation of photopatch positivity with clinical profile in patients with photoallergic dermatitis

Photopatch test (PPT) is designed to diagnose Photoallergic Contact Dermatitis (PACD) using specific dose and wavelength of irradiation. This study is a retrospective analysis of patients with photosensitivity who have undergone photopatch testing. To find the Correlation of photo patch positivity with clinical profile in patients with photoallergic dermatitis. Photo patch testing helps in determining the sensitizing potentials of commonly used day to day agents containing the allergen. Thirty-seven patients who had patch tested between July 2022and June 2023 were analyzed. The patch test antigens comprising 20 common photoallergens from Indian Standard Series were photopatch tested. Of all the patients tested the overall positivity rate was (67.56%). All patients had a characteristic clinical picture of photodermatitis for an variable duration. All patients were engaged in various occupations that involved working outdoors. The exacerbating factors were summer season in 15 (40.54%) patients, insecticides spraying in three (8.1%) and exposure to plant in ten (27%). History of contact with cement was present in six (16.21%) patients. The patients who showed positivity after irradiation was 5 (13.51 %), before and after irradiation was 7 (18.91%), and exacerbated grading after irradiation was 13 (35.13%). The commom allergen showing positivity were parthenium (29.72%), potassium dichromate (13.51%), PPD (10.81%). Apart from these allergens’ fragrance mix, paraben, neomycin sensitivity was also noted in few patients. Significant number of cases belongs to photodermatitis, thereby, finding the cause and the measures to alleviate the symptoms are paramount important. For proper diagnosis, photopatch test is essential and our study emphasis the same which can aid in appropriate management. Cosmetics, sunscreens and drugs like NSAID are found to be the emerging cause for PACD and photopatch series with relevence to above allergen is the need of the hour.

Evaluation of Four Adult Visceral Leishmaniasis Cases.

Leishmania infantum is the species responsible for visceral leishmaniasis [(VL), kala-azar], which is observed sporadically mainly in pediatric age groups in the Aegean, Mediterranean and Central Anatolian regions of Türkiye. The aim of this study is to evaluate the diagnosis, clinic, laboratory results and treatments of four adult patients with VL who applied to our hospital. The patients were referred to our hospital to investigate hematological malignancy. In the study, the data of four patients (three men, one woman; age range: 30-40 years) who were diagnosed with VL and treated in the infectious diseases clinic of our hospital between January 2022 and April 2022 were evaluated retrospectively. The diagnosis of VL was made according to appropriate clinical and physical examination findings, biochemical and serological tests (indirect fluorescent antibody test and rK39 rapid antigen test) and polymerase chain reaction (PCR) results, as well as the presence of amastigote forms of the parasite in bone marrow samples. Serology positivity was found in all patients, and bone marrow positivity was found in two patients. According to the results of RT-PCR in all patients, it was determined that the species causing the disease was L. infantum/L. donovani. Initially, the most common symptoms were fever, fatigue, and abdominal distension. None of the patients had an immunosuppressive condition. It was understood that all the patients lived in the rural area of Syria's Idlib province. Hepatosplenomegaly, increased erythrocyte sedimentation rate, anemia, leukopenia and thrombocytopenia were found in all patients. The patients were treated with liposomal amphotericin-B (L-AMB). One patient did not come for follow-ups, the other three patients were found to have completely recovered in their follow-up. No recurrence was observed in any of the patients. In conclusion, VL should be considered in patients who apply to health institutions with complaints of fever, hepatosplenomegaly, increased erythrocyte sedimentation rate, anemia, leukopenia and thrombocytopenia.

Assessing the Efficacy of a Modified Triple Drug Regimen Supplemented with Mastic Gum in the Eradication of Helicobacter pylori Infection

Abstract Introduction/Objective Helicobacter pylori (H. pylori) is a bacterium that infects the stomach and small intestine. It is known to be the main cause of gastritis and peptic ulcers. The infection is common worldwide, with a prevalence rate of 50% in many countries. Eradication of H. pylori infection is crucial, as failure to do so can lead to serious complications such as gastric cancer. Treatment for H. pylori infection involves a combination of antibiotics, proton pump inhibitors (PPIs), and bismuth compounds. However, due to the emergence of antibiotic resistance, there is a need for alternative treatments. Methods/Case Report This study had been a randomized controlled trial involving 180 patients with H. pylori infection. The patients had been divided into two groups: Group A received the standard triple-drug regimen (clarithromycin, amoxicillin, and omeprazole), while Group B received the triple-drug regimen along with mastic gum. The treatment duration was 14 days for both groups. Baseline demographics and clinical characteristics had been collected for all patients. The presence of H. pylori infection had been confirmed by a urea breath test and fecal antigen test. Results (if a Case Study enter NA) This study has investigated the effects of mastic gum on H. pylori infection. In a randomized controlled trial of 180 H. pylori-positive patients, mastic gum was found to be effective in eradicating the bacteria in 83 of 90 patients (92.2%) who received the supplementation Group B received the triple-drug regimen along with mastic gum, compared to only 57 of 90 patients (63.3%) in the group A (p < 0.001). Thus, a randomized controlled trial of 90 patients with H. pylori infection found that combination therapy of mastic gum and a triple-drug regimen resulted in a significantly higher eradication rate (92.2%) compared to a triple-drug regimen only (63.3%). Conclusion The current study investigated the adding mastic gum to the standard triple-drug regimen can improve the eradication rate of H. pylori infection. This could potentially offer an alternative treatment option for patients with H. pylori infection, especially those with antibiotic resistance. Applying the mastic gum has approved its effectiveness, and it could reduce the reliance on antibiotics and minimize the risk of resistance development.

Point-of-Care Testing for Hepatitis Viruses: A Growing Need.

Viral hepatitis, caused by hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), or hepatitis E virus (HEV), is a major global public health problem. These viruses cause millions of infections each year, and chronic infections with HBV, HCV, or HDV can lead to severe liver complications; however, they are underdiagnosed. Achieving the World Health Organization's viral hepatitis elimination goals by 2030 will require access to simpler, faster, and less expensive diagnostics. The development and implementation of point-of-care (POC) testing methods that can be performed outside of a laboratory for the diagnosis of viral hepatitis infections is a promising approach to facilitate and expedite WHO's elimination targets. While a few markers of viral hepatitis are already available in POC formats, tests for additional markers or using novel technologies need to be developed and validated for clinical use. Potential methods and uses for the POC testing of antibodies, antigens, and nucleic acids that relate to the diagnosis, monitoring, or surveillance of viral hepatitis infections are discussed here. Unmet needs and areas where additional research is needed are also described.

2305. The effect of SARS-CoV-2 antibody testing on the results of admission screening

Abstract Background Detection of SARS-CoV-2 in hospitalized patients is an important measure to prevent transmission to vulnerable individuals. Admission screening using nucleic acid amplification test such as PCR testing or rapid antigen testing (RAT) is proven to be beneficial in certain situations. However, the usefulness of SARS-CoV-2 antibody testing for COVID-19 screening in real-world setting is unclear. Methods In this study, we aimed to investigate the effect of antibody testing on the results of SARS-CoV-2 screening tests. Anti-SARS-CoV-2 spike protein antibody (S-Ab) and anti-SARS-CoV-2 nucleocapsid protein antibody (N-Ab) were measured using an electrochemiluminescence immunoassay (Elecsys, Roche Diagnostics, Rotkreuz, Switzerland) in all patients who presented to the emergency department and subsequently administered to Nagasaki University Hospital. PCR testing and RAT were also performed for the detection of SARS-CoV-2. The diagnostic performance of each antibody testing to PCR and RAT was retrospectively evaluated by Fisher's exact test and odds ratio (OR). Results A total of 2,692 patients were tested for S-Ab, N-Ab, RT-PCR, and RAT from Jan 2022 to Feb 2023. Among them, S-Ab were positive ( >0.7 U/mL) for 2,195 patients (81.5%), N-Ab ( >1.0 U/mL) 307 patients (11.4%), PCR 215 patients (7.9%), RAT 174 patients (6.5%). For those with S-Ab > 10,000 U/mL (n=625), PCR positivity was 7.0% (P=0.35, OR 0.8397) and RAT 1.8% (P< 0.0001, OR 0.2093). For those with N-Ab positive (n=307), PCR positivity was 6.8% (P=0.50, OR 0.8293) and RAT 2.6% (P=0.0019, OR 0.3577). Comparing the group of both S-Ab > 10,000 U/mL and N-Ab positive (n=128) with that of both negative (n=2564), PCR positivity was 4.7% vs. 8.1% (Fig 1, P=0.1826, OR 0.5523), and RAT positivity was 1.6% vs. 6.7% (Fig 2, P=0.0024, OR 0.1752).Fig 1.Antibody testing and PCRFig 2.Antibody testing and RAT Conclusion Antibody testing of S-Ab, N-Ab, or a combination of both showed performance in reducing the probability of positive PCR or RAT tests, indicating vaccine and infection-induced protective effect. However, the need for PCR and RAT tests for virus detection was suggested. Disclosures Kosuke Kosai, M.D., Ph.D., FUJIFILM Toyama Chemical Co., Ltd.: Commissioned research|KYORIN Pharmaceutical Co.,Ltd.: Commissioned research Koichi Izumikawa, M.D., Ph.D., Asahi Kasei Pharma Corporation: Grant/Research Support|Asahi Kasei Pharma Corporation: Honoraria|Astellas Pharma Inc.: Honoraria|DAIICHI SANKYO COMPANY, LIMITED: Grant/Research Support|DAIICHI SANKYO COMPANY, LIMITED: Honoraria|KYORIN Pharmaceutical Co.,Ltd.: Honoraria|Merck & Co., Inc.: Honoraria|Pfizer Japan Inc.: Honoraria|Shionogi & Co., Ltd.: Grant/Research Support|Shionogi & Co., Ltd.: Honoraria|Sumitomo Pharma Co., Ltd.: Grant/Research Support|Sumitomo Pharma Co., Ltd.: Honoraria|TAIHO PHARMACEUTICAL CO., LTD.: Grant/Research Support Katsunori Yanagihara, MD, PhD, FUJIFILM Toyama Chemical Co., Ltd.: Commissioned research|KYORIN Pharmaceutical Co.,Ltd.: Commissioned research

Rapid Environmental Monitoring, Capture, and Destruction Activities of SARS-CoV-2 and Bacterial Pathogens During the COVID-19 Health Emergency.

The SARS-CoV-2 pandemic is a health emergency for occupational healthcare workers at COVID-19 hospital wards in Italy. The objective of the study was to investigate the bioreactor's effectivity in monitoring and improving air quality via detection, capture, and destruction of the SARS-CoV-2 virus and bacterial pathogens, reducing the risk of transmission among healthcare workers. Bioreactors are a demonstrated effective biomonitoring system. We implemented a methodological approach wherein they were placed at various hospitals treating COVID-19 patients in Italy. The detection of the SARS-CoV-2 virus was achieved through rapid biomonitoring testing of the solutes from the AIRcel bioreactors via SARS-CoV-2 rapid test antigen and consecutive reverse transcription-polymerase chain reaction (RT-PCR) analysis with the multiplex platform (XABT) and the real-time PCR rotor-gene. The marked presence of the SARS-CoV-2 virus was found in multiple water samples via the detection of ORF1ab + N and/or E gene involved in gene expression and cellular signaling of the SARS-CoV-2 virus. The AIRcel bioreactors were able to neutralize the virus and bacterial pathogens effectively as traces of the viruses and bacteria were no longer found in multiple solute samples after an overnight period. Transmission of COVID-19 via bioaerosols, transmitted by infected patients, remains a viable threat for health workers. AIRcel bioreactors allow for rapid biomonitoring testing for early virus detection within the environment, reducing the risk of exponential contagion exposure and maintaining good air quality without endangering health workers. This sameprotocol can also be extended to public spaces as a bio-monitoring hotspot tool for early detection.

SAT597 Pituitary Abscess Growing Serratia Marcescens With Associated Clivus Osteomyelitis

Abstract Disclosure: S. Brown: None. J. Milosavljevic: None. J. Chai: None. B.Y. Wong: None. Background: Pituitary abscesses are a rare etiology for pituitary lesions (0.2%-1.1%). Up to 60% of abscesses do not have an obvious source of infection. Pituitary abscesses can develop from the spread of local infection (usually the sphenoid sinus or cavernous sinus). Commonly isolated organisms of pituitary abscesses are gram positive cocci (Staphylococcus and Streptococcus) or gram negative bacilli (E. coli, Neisseria, and Corynebacterium). We present a case of a pituitary abscess growing Serratia marcescens with associated clivus osteomyelitis. Clinical Case: A 26-year-old woman with a history of recurrent left ear infections presented with right eye pain, sixth cranial nerve palsy and headaches. Brain MRI revealed 1.2 x 0.9 x 1.2 cm septated, cystic-appearing, rim-enhancing lesion originating from the sella, exerting mild pressure on the optic chiasm and infiltrating the right cavernous sinus. Contrast-enhanced CT scan revealed sclerotic and erosive changes concerning for clivus osteomyelitis and petrous apicitis. Hormonal evaluation demonstrated panhypopituitarism with undetectable cortisol (<1.0 µg/dL, n = 4-20 µg/dL), low ACTH (2.8 pg/mL, n = 7.2-63.3pg/mL), low-normal FT4 (0.6 ng/dL, n = 0.6-1.5ng/dL), low-normal TSH (0.32 µU/mL, n = 0.3-4.2µU/mL), undetectable estradiol (<25 pg/mL, n = 10-400pg/mL), low FSH (4.1 mIU/mL, n = <20 mIU/mL), low LH (0.5 mIU/mL, n = <10 mIU/mL), elevated prolactin (79 ng/mL, n<25ng/mL), and normal IGF-1 (192 ng/mL, n = 63-373ng/mL). Blood cultures, HIV testing, hepatitis serologies, Aspergillus galactomannan and cryptococcal antigen were negative. Replacement with hydrocortisone and levothyroxine was initiated, as well as empiric treatment with ceftriaxone, vancomycin, and metronidazole. Patient then underwent trans-sphenoidal evacuation of the sellar abscess. Specimen cultures grew Serratia marcescens. Post-operatively, she developed arginine vasopressin (AVP) deficiency and was started on desmopressin. Her symptoms and sixth nerve palsy resolved after surgery, and she was discharged with hormone replacements and a 6-week course of ceftriaxone. Conclusion: While other Enterobacteriaceae have previously been isolated from pituitary abscesses (including E. coli, Citrobacter, Salmonella, Proteus and Klebsiella), our case demonstrates, to the best of our knowledge, the first case of Serratia isolated from a pituitary abscess. Serratia is considered to be an opportunistic pathogen, although this patient had no identifiable risk factors for immunosuppression. Also, pituitary abscesses commonly spread from local infections. However, the source of infection in this case is likely the clivus osteomyelitis, which to the best of our knowledge, also has never been reported. In summary, this case differs from other reported cases due to the pituitary abscess growing Serratia with a potential source from the clivus osteomyelitis. Presentation: Saturday, June 17, 2023

COVID-19 vaccination for children with pulmonary hypertension: efficacy, safety and reasons for opting against vaccination.

To determine the reasons why pulmonary hypertension (PH) children refused vaccination against COVID-19, evaluate the safety and efficacy of COVID-19 vaccine in PH children. This retrospective cohort study included congenital heart disease-associated pulmonary arterial hypertension (CHD-PAH) and bronchopulmonary dysplasia associated PH (BPD-PH) children who were divided into vaccinated group and non-vaccinated group. Univariate logistic regression analysis and multivariate logistic regression analysis were conducted to explore the reasons why PH children refused COVID-19 vaccine. Then, the prevalence, the number of symptoms, and the severity of COVID-19 disease were compared between the vaccinated and unvaccinated groups. We included 73 children and 61 children (83.6%) were unvaccinated. The main reasons for not being vaccinated were fear of worsening of existing diseases (31%). Age < 36 months (RR: 0.012; P < 0.001) and the presence of comorbidities (RR = 0.06; P = 0.023) were risk factors influencing willingness to vaccinate. The most common adverse events (AEs) were injection site pain (29.6%). COVID-19 vaccines are safe for PH children. The prevalence of COVID-19 disease decreased in PH children after vaccination (RR = 0.51; P = 0.009). 1 month after negative nucleic acid test or negative antigen test, PH children in the vaccinated group had fewer symptoms (P = 0.049). The vaccination rate of COVID-19 vaccine is low in CHD-PAH and BPD-PH children while COVID-19 vaccines are safe. Vaccination can reduce the prevalence of COVID-19 disease and the number of symptoms 1 month after negative nucleic acid or antigen tests.

Linear epitope mapping in the E and NS1 proteins of dengue and Zika viruses: Prospection of peptides for vaccines and diagnostics.

The arrival of the Zika virus (ZIKV) in dengue virus (DENV)-endemic areas has posed challenges for both differential diagnosis and vaccine development. Peptides have shown promise in addressing these issues. The aim of this study was to identify the linear epitope profile recognized by serum samples from dengue and Zika patients in the E and NS1 proteins of DENV and ZIKV. This cross-sectional study included individuals of all ages with laboratory-confirmed DENV and ZIKV infections, who were selected through convenience sampling. The serum samples from dengue and Zika patients detected epitopes evenly distributed across the viral proteins in a peptide microarray platform. However, several epitopes were located within "epitope hotspots", characterized by clusters of peptides recognized in more than 30% of the sub-arrays analyzed using individual or pooled serum samples. The serum samples from dengue and Zika patients showed a high level of cross-reactivity with peptides in the DENV and ZIKV proteins. Analysis using an additional peptide microarray platform, which contained peptides selected based on the results of the initial screening, revealed that two DENV and one ZIKV peptide, highly specific to their related viruses, were located within the epitope hotspots; however, they presented low detection rates (32.5, 35.0, and 28.6%, respectively). In addition, two DENV peptides detected at similarly high rates by both dengue and Zika patients were also found within the epitope hotspots. These hotspots contain several immunodominant epitopes that are recognized by a larger number of individuals when compared to 15-amino acid (aa) sequence peptides. Thus, epitope hotspots may have greater potential to serve as antigens in diagnostic tests and vaccine development than peptides composed of only 15 amino acids.

Deep learning approach for detection of Dengue fever from the microscopic images of blood smear

Dengue virus (DENV), known to cause dengue fever is a global public health concern. A safe and effective anti-viral drug or vaccine that can protect humans from dengue fever currently does not exist. Today, severe dengue has become a leading cause of serious illness in most Asian and Latin American countries. This digital pathology-related research focuses on the automatic detection of dengue by utilizing digital microscopic peripheral blood smears (PBS). This paper explored pre-trained convolution neural network (CNN) architectures for automatic dengue fever detection. Transfer learning (TL) was performed on two widely used pre-trained CNNs - SqueezeNet and GoogleNet, and employed to differentiate the dengue-infected and normal blood smears. The last few layers were replaced and retrained to customize the architectures for this task. Leishman’s stained dengue-infected and normal control 100x magnified PBS images were included in the study. The best performance was rendered by GoogleNet (Learn Rate, 0.0001; Batch Size, 8) with an Accuracy 91.30%, Sensitivity 84.62%, Specificity 100%, Precision 100%, and F1 score 91.67%. Promising results show that this approach can be an essential adjunct to other clinical methods, namely CBC test & NS1 antigen capture, and can significantly support dengue diagnosis in low-resource setups.

PGT-HLA programmes for the cure of a sick sibling: clinical strategies for this challenging search

The ultimate goal of a preimplantation genetic testing and human leukocyte antigen (PGT-HLA) matching programme is the birth of a healthy, HLA-compatible child for the treatment or cure of a sick sibling. Several authors have published successful cases of the births of children HLA-matched to siblings affected by different conditions and diseases. However, there are many reports of failed attempts. Couples seeking an HLA-matched sibling for their affected child look for positive outcomes in the shortest possible time. Nevertheless, there is no published consensus or guidelines with recommendations for these cases. Here, the authors aimed to analyse different approaches for these programmes, highlighting the most promising strategies for the families and fertility units. Furthermore, the authors mention a successful case of a PGT-HLA matching programme after a previous failed attempt following the strategies proposed. Which is the most cost-effective and time-efficient approach in a PGT-HLA matching programme?

CD4+TGFβ+ cells infiltrated the bursa of Fabricius following IBDV infection, and correlated with a delayed viral clearance, but did not correlate with disease severity, or immunosuppression.

Infectious Bursal Disease Virus (IBDV) causes immunosuppression in chickens. While B-cell destruction is the main cause of humoral immunosuppression, bursal T cells from IBDV-infected birds have been reported to inhibit the mitogenic response of splenocytes, indicating that some T cell subsets in the infected bursa have immunomodulatory activities. CD4+CD25+TGFβ+ cells have been recently described in chickens that have immunoregulatory properties and play a role in the pathogenesis of Marek's Disease Virus. To evaluate if CD4+CD25+TGFβ+ cells infiltrated the bursa of Fabricius (BF) following IBDV infection, and influenced the outcome of infection, birds were inoculated at either 2 days or 2 weeks of age with vaccine strain (228E), classic field strain (F52/70), or PBS (mock), and bursal cell populations were quantified by flow cytometry. Both 228E and F52/70 led to atrophy of the BF, a significant reduction of Bu1+-B cells, and a significant increase in CD4+ and CD8α+ T cells in the BF, but only F52/70 caused suppression of immune responses to a test antigen in younger birds, and clinical signs in older birds. Virus was cleared from the BF more rapidly in younger birds than older birds. An infiltration of CD4+CD25+T cells into the BF, and elevated expression of bursal TGFβ-1+ mRNA was observed at all time points following infection, irrespective of the strain or age of the birds, but CD4+TGFβ+cells and CD4+CD25+TGFβ+ cells only appeared in the BF at 28 dpi in younger birds. In older birds, CD4+TGFβ+ cells and CD4+CD25+TGFβ+ cells were present at earlier time points, from 7dpi following 228E infection, and from 14 and 28 dpi following F52/70 infection, respectively. Our data suggest that an earlier infiltration of CD4+TGFβ+ cells into the BF correlated with a delayed clearance of virus. However, the influx of CD4+TGFβ+ cells and CD4+CD25+TGFβ+ into the BF did not correlate with increased pathogenicity, or immunosuppression.