Negative Culture Results Research Articles

LBODP100 A Rare Case Of Pembrolizumab Induced Graves’ Disease

Abstract Cancer immunotherapies have recently changed the therapeutic armamentarium of anti-cancer treatments, particularly for melanoma and cancers of the kidneys, lungs, and colon. Immune checkpoint inhibitors (ICPis) act on various immune checkpoints. Of them, anti-PD-1 antibodies (such as pembrolizumab) are monoclonal antibodies that act against programmed cell death 1 protein. However, by counteracting the regulators of adaptive immunity, this class of drugs may cause immune-related adverse events that involve multiple organs and endocrine glands, such as the thyroid gland. The symptoms of thyroid dysfunction usually present during the first weeks of ICPis therapy. In the current report, we present a case of a 50-year-old male who presented to the emergency department complaining of fever, chills, nausea, and vomiting for one week. The patient had a history of colon cancer with lymph node metastasis status post tumor resection and colostomy. He began Keytruda® (pembrolizumab) treatment after tumor resection, and the presenting symptoms appeared after receiving the first immunotherapy infusion. His medical history was significant for psoriasis and rheumatoid arthritis. The patient's history was unremarkable for thyroid diseases, and he did not receive thyroid medications with no previous exposure to intravenous contrast media, over-the-counter iodine preparations, or biotin. At the emergency department, the patient had a temperature of 101.4°F, a heart rate of 110 bpm, and blood pressure of 130/70 mm Hg. On examination, tenderness was indicated upon palpating the anterior part of the neck. The patient was treated with intravenous fluids, steroids, beta-blockers, and broad-spectrum antibiotics. A workup for sepsis was requested, and it revealed negative blood culture and urine culture results. His laboratory indices demonstrated a suppressed level of TSH (0. 01 mIU/mL) and elevated Free T4 (3.16 ng/dl). Still, his TSH level reported at the Oncology clinic before Keytruda administration was (0.9 mIU/mL), and Free T4 was (1.7 ng/dl). Thyroid ultrasound revealed a heterogeneous thyroid gland consistent with thyroiditis. Antibody testing showed positive thyroid antithyroglobulin antibodies and elevated thyroid-stimulating antibodies (TSI). A radioactive iodine uptake test was ordered, revealing increased contrast uptake. These findings suggested that the cause of thyroid dysfunction was Graves’ disease. The patient was started on Methimazole 20mg per day and discharged home after scheduling an outpatient follow-up appointment with the endocrinologist. This case is one of the rare cases of thyrotoxicosis attributable to Graves’ disease related to pembrolizumab therapy. To the best of our knowledge, two studies in the literature reported three cases of ICPi-induced thyrotoxicosis with thyroid antibody positivity following anti-PD-1 antibody therapy. Presentation: No date and time listed

Colistin-Induced Neurotoxicity in a Multidrug-Resistant UTI Patient with Cervical Cancer: A Case Report

Introduction: There has been a rise in the reappearance of multidrug-resistant Gram-negative bacteria in recent years. Using polymyxins, such as colistin, as a last-line treatment for these infections has led to renewed interest in the toxic effects of this drug. Case Presentation: In this case report, we present neurological signs and symptoms developed in a patient with a history of cervical cancer four to five hours after receiving colistin for treating a urinary tract infection caused by MDR Pseudomonas aeruginosa with a colony count of > 100,000/L. These signs and symptoms included lower limb hemiparesis, facial paresthesia, decreased deep tendon reflexes, and tinnitus, which were resolved on their own 24 hours after discontinuation of the drug. Antibiotic therapy was continued with pipractate and ciprofloxacin instead. The patient got discharged in stable condition after negative urine culture results.

Comparing outcomes between culture-positive and culture-negative septic shock in a PICU: A retrospective cohort study.

BackgroundWe assessed the outcomes and characteristics of culture-negative septic shock (CNSS) and culture-positive septic shock (CPSS) in pediatric intensive care unit (PICU).MethodsWe performed a retrospective study on the data of children admitted to the PICU due to septic shock between January 2018 and December 2021. The primary outcome was in-hospital mortality. The secondary outcomes were the length of stay (LOS) of hospital, the need for mechanical ventilation (MV) and continue renal replacement therapy (CRRT).ResultsOverall, 238 patients were enrolled. 114 patients (47.9%) had positive cultures (60 blood samples, 41 sputum samples, 17 pus samples, and 19 others), 18 of whom were cultured positive at two sites, 1 at three sites, and 3 had two different types of bacteria at same site. The in-hospital mortality was 47.1%. There were no significant differences in the in-hospital mortality (47.6% vs. 46.5%, P = 0.866), PRISM-III score (10 vs. 12, P = 0.409), PIM-3 score (0.08 vs. 0.07, P = 0.845), pSOFA score (10 vs. 10, P = 0.677) or the need for MV (64.5% vs. 68.4%, P = 0.524) and CRRT (29.8% vs. 34.2%, P = 0.470) between the CNSS group and the CPSS group. The Procalcitonin (8.89 ng/ml vs. 28.39 ng/ml, P = 0.001) and C-reactive protein (28 mg/L vs. 58 mg/L, P = 0.001) levels were significantly lower in the CNSS group than in the CPSS group, while WBC count (9.03 × 109/L vs. 5.02 × 109/L, P = 0.002) and serum sodium (137 mmol/L vs. 132 mmol/L, P = 0.001) was significantly higher in CNSS. The LOS of hospital was significantly longer (16 days vs. 11 days, P = 0.011) in the CPSS group than in the CNSS group, while the LOS of PICU (5 days vs. 4 days, P = 0.094) stay was not significantly different.ConclusionCompared with children with CNSS, children with CPSS had higher PCT and CRP levels, but lower WBC count. Children with CPSS had longer LOS of hospital. However, positive or negative culture results were not associated with in-hospital mortality, the LOS of PICU, the need for MV or CRRT in children with septic shock.

Clinical scoring system to predict viable viral shedding in patients with COVID-19.

Background: The Centers for Disease Control and Prevention (CDC) recommends 5–10 days of isolation for patients with COVID-19, depending on symptom duration and severity. However, in clinical practice, an individualized approach is required. We thus developed a clinical scoring system to predict viable viral shedding.Methods: We prospectively enrolled adult patients with SARS-CoV-2 infection admitted to a hospital or community isolation facility between February 2020 and January 2022. Daily dense respiratory samples were obtained, and genomic RNA viral load assessment and viral culture were performed. Clinical predictors of negative viral culture results were identified using survival analysis and multivariable analysis.Results: Among 612 samples from 121 patients including 11 immunocompromised patients (5 organ transplant recipients, 5 with hematologic malignancy, and 1 receiving immunosuppressive agents) with varying severity, 154 (25%) revealed positive viral culture results. Multivariable analysis identified symptom onset day, viral copy number, disease severity, organ transplant recipient, and vaccination status as independent predictors of culture-negative rate. We developed a 4-factor predictive model based on viral copy number (-3 to 3 points), disease severity (1 point for moderate to critical disease), organ transplant recipient (2 points), and vaccination status (-2 points for fully vaccinated). Predicted culture-negative rates were calculated through the symptom onset day and the score of the day the sample was collected.Conclusions: Our clinical scoring system can provide the objective probability of a culture-negative state in a patient with COVID-19 and is potentially useful for implementing personalized de-isolation policies beyond the simple symptom-based isolation strategy.

Association of Procalcitonin with the Patient's Infection Characteristics and Prognosis after Hematopoietic Stem Cell Transplantation.

Objective To study whether procalcitonin (PCT) is an important indicator of infection with or without agranulocytosis and to reveal whether PCT can distinguish between infected sites and affect prognosis after hematopoietic stem cell transplantation (HSCT). Method In the present study, 682 patients with HSCT were enrolled, and their clinical characteristics were noted. Their blood culture and inflammatory and biochemical indicators were studied. The patients were divided into respective groups according to the degree of agranulocytosis, type of bacterial infection, infected sites, and prognosis. Results The PCT, CRP, and D-dimer levels were significantly improved in patients with positive blood culture results compared to the case for those with negative blood culture results. The PCT level was the highest in the gram-negative group. The levels of PCT and D-dimer were significantly elevated in patients with infection and agranulocytosis after HSCT compared to those in the nonagranulocytosis cohort. Interestingly, no significant difference in the PCT level was observed among any of the eight foci. Lower PCT levels were associated with higher survival in patients with infection after HSCT. Conclusion Among patients that underwent HSCT, PCT levels were significantly elevated in those with infection and agranulocytosis, with the levels being specifically high in the gram-negative group. Moreover, lower PCT levels were associated with higher survival in patients with infection after HSCT.

The characteristics of bacteremia among patients with acute febrile illness requiring hospitalization in Indonesia.

Blood culturing remains the "gold standard" for bloodstream infection (BSI) diagnosis, but the method is inaccessible to many developing countries due to high costs and insufficient resources. To better understand the utility of blood cultures among patients in Indonesia, a country where blood cultures are not routinely performed, we evaluated data from a previous cohort study that included blood cultures for all participants. An acute febrile illness study was conducted from July 2013 to June 2016 at eight major hospitals in seven provincial capitals in Indonesia. All participants presented with a fever, and two-sided aerobic blood cultures were performed within 48 hours of hospital admission. Positive cultures were further assessed for antimicrobial resistance (AMR) patterns. Specimens from participants with negative culture results were screened by advanced molecular and serological methods for evidence of causal pathogens. Blood cultures were performed for 1,459 of 1,464 participants, and the 70.6% (1,030) participants that were negative by dengue NS1 antigen test were included in further analysis. Bacteremia was observed in 8.9% (92) participants, with the most frequent pathogens being Salmonella enterica serovar Typhi (41) and Paratyphi A (10), Escherichia coli (14), and Staphylococcus aureus (10). Two S. Paratyphi A cases had evidence of AMR, and several E. coli cases were multidrug resistant (42.9%, 6/14) or monoresistant (14.3%, 2/14). Culture contamination was observed in 3.6% (37) cases. Molecular and serological assays identified etiological agents in participants having negative cultures, with 23.1% to 90% of cases being missed by blood cultures. Blood cultures are a valuable diagnostic tool for hospitalized patients presenting with fever. In Indonesia, pre-screening patients for the most common viral infections, such as dengue, influenza, and chikungunya viruses, would maximize the benefit to the patient while also conserving resources. Blood cultures should also be supplemented with advanced laboratory tests when available.

Diagnosis of pathogens causing bacterial meningitis using Nanopore sequencing in a resource-limited setting

AimThe aim of the present study is to compare the performance of 16S rRNA Nanopore sequencing and conventional culture in detecting infectious pathogens in patients with suspected meningitis in a resource-limited setting without extensive bioinformatics expertise.MethodsDNA was isolated from the cerebrospinal fluid (CSF) of 30 patients with suspected bacterial meningitis. The isolated DNA was subjected to 16S sequencing using MinION™. The data were analysed in real time via the EPI2ME cloud platform. The Nanopore sequencing was done in parallel to routine microbiological diagnostics.ResultsNanopore sequencing detected bacterial pathogens to species level in 13 of 30 (43%) samples. CSF culture showed 40% (12/30) positivity. In 21 of 30 patients (70%) with suspected bacterial meningitis, both methods yielded concordant results. About nine of 30 samples showed discordant results, of these five were false positive and four were false negative. In five of the culture negative results, nanopore sequencing was able to detect pathogen genome, due to the higher sensitivity of the molecular diagnostics. In two other samples, the CSF culture revealed Cryptococcus neoformans and Streptococcus pneumoniae, which were not detected by Nanopore sequencing. Overall, using both the cultures and 16S Nanopore sequencing, positivity rate increased from 40% (12/30) to 57% (17/30).ConclusionNext-generation sequencing could detect pathogens within six hours and could become an important tool for both pathogen screening and surveillance in low- and middle-income countries (LMICs) that do not have direct access to extensive bioinformatics expertise.

Diagnosis of paediatric TB using Xpert® MTB/RIF Ultra on fresh respiratory samples.

SUMMARYOBJECTIVE:To evaluate the diagnostic accuracy of Xpert® MTB/RIF Ultra (Ultra) on fresh respiratory samples for the diagnosis of pulmonary TB (PTB) in children.METHODS:Between July 2017 and December 2019, children with presumed TB were prospectively enrolled at clinical sites in three African countries. Children were assessed using history, physical examination and chest X-ray. Sputum or gastric aspirate samples were analysed using Ultra and culture. The diagnostic accuracy of Ultra was calculated against culture as the reference standard.RESULTS:In total, 547children were included. The median age was 4.7 years, 77 (14.1%) were HIV infected and 77 (14.1%) had bacteriologically confirmed TB. Ultra detected an additional 20 cases in the group of children with negative culture results. The sensitivity of Ultra was 66.3% (95% CI 47–82), and the specificity was 95.4% (95% CI 89–99) when assessed against culture as the reference standard.CONCLUSION:Despite the improved performance of Ultra as compared to Xpert as was previously reported, its sensitivity remains sub-optimal for the detection of TB in children. Ultra detected additional 20 cases which otherwise could not have been detected by culture alone, suggesting that the latter is an imperfect reference standard.

Association between duration of early empiric antibiotics and necrotizing enterocolitis and late-onset sepsis in preterm infants: a multicenter cohort study

The threshold to initiate empiric antibiotics for suspicion of early-onset sepsis (EOS) is low in preterm infants. Antibiotics’ effects on short-term outcomes have recently been debated. We aimed at exploring the extent of early empiric antibiotic exposure (EEAE) in preterm infants and the association between the duration of EEAE with necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) within different EEAE groups. EEAE practice for suspicion of EOS was evaluated in all included infants (gestational age < 30 weeks) born in 9 centers in the Netherlands and Belgium between Oct. 2014 and Jan. 2019. EEAE association with NEC and LOS development was analyzed by multivariate regression. After excluding 56 EOS cases, 1259 infants were included. A total of 1122 infants (89.1%) were exposed to empirical antibiotics for the suspicion of EOS of whom 802 (63.7%) had short (≤ 72 h) and 320 (25.4%) prolonged EEAE (> 72 h). Infants with EEAE ≤ 72 h had a lower incidence of NEC compared to both infants without EEAE (adjusted odds ratio (aOR) 0.39; 95% confidence interval (CI) [0.19–0.80]; p = 0.01) and with prolonged EEAE (> 72 h) (aOR [95%CI]: 0.58 [0.35–0.96]; p = 0.03). With every additional day of EEAE, LOS incidence decreased (aOR [95%CI]: 0.90 [0.85–0.97]; p = 0.003).Conclusion: Almost 90% of preterm infants who have negative blood culture results in the first 72 h of life are exposed to EEAE under suspicion of EOS. One-fourth has prolonged EEAE. Duration of EEAE was differently associated with NEC and LOS incidence. The effects of antibiotics, and potentially induced microbial dysbiosis related to development of NEC and LOS, should further be explored.What is Known:• Preterm infants often receive antibiotics empirically directly after birth for suspicion of early-onset sepsis.• The effects of the duration of early empirical antibiotic exposure on the risk for necrotizing enterocolitis and late-onset sepsis are debated.What is New:• Almost 90% of preterm infants with a gestational age below 30 weeks are exposed to antibiotics empirically after birth despite negative culture results. In a quarter of these culture-negative infants, empirical antibiotics are prolonged.• A short course of empirical antibiotics (≤72h) is associated with decreased odds for necrotizing enterocolitis compared to both prolonged (>72h) or no empirical antibiotics after birth. Furthermore, every additional day of empirical antibiotic exposure is associated with decreased risk for late-onset sepsis in the first month of life.

The role of metagenomic next-generation sequencing in the pathogen detection of invasive osteoarticular infection

ObjectivesThis study aimed to analyze the pathogenic bacteria spectrum in invasive and primary osteoarticular infection (IOI and POI) and compare the pathogen detection rate of metagenomic next-generation sequencing (mNGS) and microbial culture in IOI and POI. MethodsThe suspected POI and IOI cases from 2014-2021 were included. The diagnosis of POI or IOI was made by at least two orthopedic surgeons, two infectious diseases specialists, and one senior microbiologist. Demographic characteristics, microbial culture results, and so on were recorded. The pathogenic bacteria spectrum in IOI and POI were analyzed, and the ability of mNGS and microbial culture in pathogen detection in IOI and POI were compared. ResultsThere were 52 POI cases and 92 IOI cases; the common pathogen in POI and IOI were both Staphylococcus aureus. There are more cases with negative microbial culture results and multiple infections in IOI, and many cases were caused by rare and fastidious bacteria. The introduction of the mNGS could significantly increase the pathogen detection rate to 92.39% in IOI, which was 8.69% higher than that of microbial culture (P = 0.007), whereas the improvement in POI was limited to about 2%. ConclusionmNGS is an promising tool for IOI pathogen detection.

The Utility of Acid-Fast Bacillus (AFB) and Fungal Cultures in Orthopaedic Infections.

IntroductionWhen diagnosing suspected orthopaedic-related infections, fungal and acid-fast bacilli (AFB) cultures are often obtained intraoperatively. These cultures are difficult and time-consuming to grow and increase healthcare costs. This study aimed to quantify the rate of positive AFB and fungal cultures in orthopaedic infections and to compare potential risk factors for a positive result. MethodsOrthopaedic surgical cases for suspected infection at one institution from March 2013 through December 2019 were included. Data were collected on patient demographics and procedure characteristics for patients with surgical AFB or fungal lab tests ordered on the day of surgery.ResultsOf the 813 patients for whom intraoperative AFB or fungal cultures were ordered, 3.8% (N=31) had a positive result. Of the 31 positive results, 30 were from fungal cultures and one was from AFB cultures. Patients with a positive versus negative culture result did not differ significantly by age, sex, American Society of Anesthesiologists (ASA) score, diabetes, obesity, or HIV/AIDS. In both unadjusted and adjusted analyses, peripheral vascular disease (PVD) was associated with higher odds of a positive fungal culture result (adjusted OR (aOR)=3.5, 95%CI=1.3-8.4). Likewise, in both unadjusted and adjusted models, a hand/foot operating region was associated with higher odds of a positive fungal culture result compared with all other regions (aOR=4.2, 95%CI=1.9-9.8).ConclusionIntraoperative fungal and AFB cultures may not need to be obtained except in orthopaedic surgical cases for hand or foot infections or in patients with PVD.

Analysis of clinical features and treatment of pyoderma gangrenosum

Objective: To explore the clinical features and treatment of pyoderma gangrenosum (PG). Methods: A retrospective observational study was conducted. From January 2012 to July 2021, 25 patients with PG who met the inclusion criteria were admitted to Beijing Fucheng Hospital, including 16 males and 9 females, with the age of onset of disease being 14 to 75 years. Among them, the classification of PG identified 17 cases of ulcerative type, 6 cases of pustular type, 1 case of proliferative type, and 1 case of bullous type. Six patients were accompanied with systemic diseases, while 19 patients were not accompanied with systemic diseases. At the same time of systemic treatment with glucocorticoids, dressing changes or surgical skin grafting was performed on the wounds. The results of laboratory and histopathological examinations, the overall curative effects and follow-up of patients, the wound healing time of patients with negative and positive microbial culture results of wound secretion specimens, and the curative effects of patients with and without systemic diseases were analyzed. Results: The results of blood routine examination of 19 patients were abnormal, and all the immunological indexes were normal in all the patients; the microbial culture results of wound secretion specimens were positive in 14 patients; and the histopathological examination results of ulcer boundary tissue in 15 patients with rapid wound progress were mainly local tissue inflammatory changes. The wounds were cured in 17 patients, mostly healed in 7 patients, and not healed in 1 patient. After one-year's follow-up, the PG in 3 patients relapsed due to self-discontinuation of medication after discharge, and the wounds were healed gradually after adjustment of medication, while the remaining patients had no relapse. The days of wound healing in 14 patients with positive microbial culture results of wound secretion specimens were 21-55 days, and the days of wound healing in 11 patients with negative microbial culture results in wound secretion specimens were 20-54 days. In the 6 patients with systemic diseases, the wounds of 3 patients were cured, and the wounds of the other 3 patients were mostly healed. In the 19 patients without systemic diseases, the wounds of 14 patients were cured, the wounds of 4 patients were mostly healed, and the wound of 1 patient was not healed. Conclusions: The laboratory examination and pathological manifestations of patients with PG lacks characteristics, and their clinical manifestations are rich and diverse, thus PG can be easily misdiagnosed. The glucocorticoids combined with immunosuppressive therapy have good effects on PG. Surgical intervention can be performed on the wounds. Specifically, excessive debridement is not recommended in the acute phase, but skin grafting can be performed in the contraction phase.

COVID19 INFECTION AND LIBMAN –SACKS ENDOCARDITIS IN PAST VALVE REPAIRED PATIENT

Objective: The patient was a 61-year-old woman who typically underwent mitral valve replacement and tricuspid valve repair in 2011. During these years, she underwent an annual checkup and experienced no particular problems. The potential patient contracted Covid 19 a month ago and underwent conservative treatment. The patient displayed no specific symptoms, no fever, and her Covid 19 disease was mild. In the accompanying echocardiography, we notice a lump on the atrial surface of the Tricuspid valve that we instantly suspect of local vegetation or heart mass. As a result, we admitted the patient to resume the examination. Design and method: Multi-slice (16) spiral thoracic CT scan: Sternotomy and MVR are seen. Cardiomegaly is evident. Patchy peripheral ground-glass opacities are seen bilaterally, suggesting covid-19 pneumonia; correlation with clinical and paraclinical data is recommended. Degenerative changes are perceived in the thoracic spine. There is no pleural effusion. Blood cultures and urinary trachea were requested to diagnose endocarditis, and she was also asked to have an esophageal echocardiogram. The antibiotic Meropenem 500 was started three times a day with vancomycin 1 gram twice a day for prophylaxis. After these examinations, the mass diagnosis was rejected as the image of vegetation on echocardiography did not found echogenicity similar to cardiac tissue and was denser. Consequently, we diagnosed vegetation. According to the negative culture results, and the patient had no symptoms (chills, heart pain), this patient’s diagnosis of an immunological reaction caused by Covid disease was made. Libman –sacks endocarditis is a type of sterile nonbacterial thrombotic endocarditis (NBTE) secondary to inflammation. Results: In this rare case, the vital point is that immunological reaction after covid can give rise to vegetation on the heart artificial valve and can be typically established with endocarditis. Covid can cause libman sac endocarditis, then we consider patients with heart disease maybe get limban sac or other forms of immunological reaction after covid virus. Conclusions: Concerning the explicit rejection of all the causes, the patient was diagnosed correctly with limb sac endocarditis. She underwent anticoagulant therapy and corticosteroid therapy accordingly and was recovered fully.

Comparison of Peritonitis Relapse Incidence in End-Stage Renal Disease Patients with Peritoneal Dialysis According to the Culture Results

Background: Peritoneal dialysis (PD) is one of the modalities of renal replacement therapy (RRT) in end-stage renal disease (ESRD). One of the complications that are often found in the use of PD is peritonitis. Presence of the culture from the peritoneal fluid was known to be associated with the incidence of peritonitis relapse among ESRD patients with PD. Aim: Comparing the incidence of relapse in patients with continuous ambulatory peritoneal dialysis (CAPD) with culture-negative and culture-positive in RSUD Dr. Saiful Anwar Malang. Methods: This study measured the incidence of relapse after administration of CAPD peritonitis therapy. Descriptive data are presented in percentages, and numerical data is presented in Mean ± SD. The analysis test was carried out using the Mann-Whitney with p&lt;0.05, significant. Results: According to the culture results, it was found that 25.4% (18 of 71 PD peritonitis cultures) were culture-negative in patients with CAPD peritonitis. This result is slightly higher than the ISPD recommendation, with 20% culture-negative results. There were 3 out of 53 relapses in culture-positive subjects and 1 in 18 relapses in culture-negative subjects. There was no significant difference in the two groups, with an OR of 0.721 in the culture-positive group lead the culture-positive tended to experience no relapse by 0.721 times less than the patient with culture-negative. Conclusion: In peritoneal dialysis peritonitis, there was no significant difference in the incidence of relapse in the positive and culture-negatives.

Comparison of an automated DNA extraction and 16S rDNA real time PCR/sequencing diagnostic method using optimized reagents with culture during a 15-month study using specimens from sterile body sites

Background16S rDNA-PCR for the identification of a bacterial species is an established method. However, the DNA extraction reagents as well as the PCR reagents may contain residual bacterial DNA, which consequently generates false-positive PCR results. Additionally, previously used methods are frequently time-consuming. Here, we describe the results obtained with a new technology that uses DNA-free reagents for automated DNA extraction and subsequent real time PCR using sterile clinical specimens.ResultsIn total, we compared 803 clinical specimens using real time PCR and culturing. The clinical specimens were mainly of orthopedic origin received at our diagnostic laboratory. In 595 (74.1%) samples, the results were concordant negative, and in 102 (12.7%) the results were concordant positive. A total of 170 (21.2%) clinical specimens were PCR-positive, of which 62 (36.5% from PCR positive, 7.7% in total) gave an additional benefit to the patient since only the PCR result was positive. Many of these 62 positive specimens were strongly positive based on crossingpoint values (54% < Cp 30), and these 62 positive clinical specimens were diagnosed as medically relevant as well. Thirty-eight (4.2%) clinical specimens were culture-positive (25 of them were only enrichment culture positive) but PCR-negative, mainly for S. epidermidis, S. aureus and C. acnes. The turnaround times for negative specimens were 4 hours (automated DNA extraction and real time PCR) and 1 working day for positive specimens (including Sanger sequencing). Melting-curve analysis of SYBR Green-PCR enables the differentiation of specific and unspecific PCR products. Using Ripseq, even mixed infections of 2 bacterial species could be resolved.ConclusionsFor endocarditis cases, the added benefit of PCR is obvious. The crucial innovations of the technology enable timely reporting of explicit reliable results for adequate treatment of patients. Clinical specimens with truly PCR-positive but culture-negative results represent an additional benefit for patients. Very few results at the detection limit still have to be critically examined.

A Genome-Wide Association Study for Tolerance to Paratuberculosis Identifies Candidate Genes Involved in DNA Packaging, DNA Damage Repair, Innate Immunity, and Pathogen Persistence

Although the genetic susceptibility to diseases has been extensively studied, the genetic loci and the primary molecular and cellular mechanisms that control disease tolerance are still largely unknown. Bovine paratuberculosis (PTB) is an enteritis caused by Mycobacterium avium subsp. paratuberculosis (MAP). PTB affects cattle worldwide and represents a major issue on animal health. In this study, the associations between host genetic and PTB tolerance were investigated using the genotypes from 277 Spanish Holstein cows with two distinct phenotypes: cases) infected animals with positive PCR and bacteriological culture results but without lesions in gut tissues (N= 24), and controls) animals with negative PCR and culture results but with PTB-associated lesions (N= 253). DNA from peripheral blood of the study population was genotyped with the Bovine EuroG MD Bead Chip, and the corresponding genotypes were imputed to whole-genome sequencing (WGS) data. A genome-wide association study was performed using the WGS data and the defined phenotypes in a case-control approach. A total of 142 single nucleotide polymorphisms (SNPs) were associated (false discovery rate ≤ 0.05, P values between 1.5 × 10-7 and 5.7 × 10-7) with tolerance (heritability= 0.55). The 40 SNPs with P-values < 5 × 10-7 defined 9 QTLs and 98 candidate genes located on BTA4, BTA9, BTA16, BTA25, and BTA26. Some of the QTLs identified in this study overlap with QTLs previously associated with PTB, bovine tuberculosis, mastitis, somatic cell score, bovine diarrhea virus persistent infection, tick resistance, and length of productive life. Two candidate genes with important roles in DNA damage response (ERCC4 and RMI2) were identified on BTA25. Functional analysis using the 98 candidate genes revealed a significant enrichment of the DNA packaging process (TNP2/PRMI1/PRM2/PRM3). In addition, the TNF-signaling (bta04668; TRAF5/CREB5/CASP7/CHUK) and the toxoplasmosis (bta05145; TGFβ2/CHUK/CIITA/SOCS1) pathways were significantly enriched. Interestingly, the nuclear Factor NF-κβ Inhibitor Kinase Alpha (CHUK), a key molecule in the regulation of the NF-κB pathway, was enriched in both pathways. Taken together, our results define a distinct immunogenetic profile in the PTB-tolerant animals designed to control bacterial growth, modulate inflammation, limit tissue damage and increase repair, thus reducing the severity of the disease.

Community-Acquired Pneumonia

Community-acquired pneumonia is an important cause of morbidity and mortality. It can be caused by bacteria, viruses, or fungi and can be prevented through vaccination with pneumococcal, influenza, and COVID-19 vaccines. Diagnosis requires suggestive history and physical findings in conjunction with radiographic evidence of infiltrates. Laboratory testing can help guide therapy. Important issues in treatment include choosing the proper venue, timely initiation of the appropriate antibiotic or antiviral, appropriate respiratory support, deescalation after negative culture results, switching to oral therapy, and short treatment duration.

Pleural Peels Tissue Culture plus Pleural Fluid Culture Help to Improve Culture Rate for Empyema.

Background: Empyema is known as a serious infection, and outcomes of empyema cases remain poor. Pleural fluid culture and blood culture have been reported to give unsatisfactory results. We introduce a novel pleural peels tissue culture during surgery and aim to improve the culture results of empyema. Methods: This was a retrospective study and was obtained from our institute. Patients with stage II or III empyema undergoing video-assisted thoracic surgery decortication from January 2019 to June 2021 were included in the study. Results: There were 239 patients that received a pleural peels tissue culture, a pleural fluid culture, and a blood culture concurrently during the perioperative period. Of these, 153 patients had at least one positive culture and 86 patients showed triple negative culture results. The positive culture rates were 46.9% for pleural peels tissue cultures, 46.0% for pleural fluid cultures, and 10% for blood cultures. The combination of pleural peels tissue culture and pleural fluid culture increased the positive rate to 62.7%. Streptococcus species and Staphylococcus species were the most common pathogens. Conclusion: The combination of pleural peels tissue culture and pleural fluid culture is an effective method to improve the positive culture rate in empyema.

Evaluation of Procalcitonin Diagnostic Accuracy with Comparison to Blood Culture

Background: Procalcitonin has been used globally as indicator marker of sepsis to define bacteremia or blood stream infection for early patient management or antibiotic therapy. Blood culture refers to a microbiological culture of a peripheral blood sample. The blood cultures help to determine the presence of systemic infections, such as septicaemia. If the culture is positive, the causative micro-organism can usually be identified, and antibiotic sensitivity testing performed. On the other hand, the sensitivity of procalcitonin in comparison to its specificity to certain bacterial infections is still in question. Methodology: In this study, we selected 309 patients without restriction of age gender with pre-diagnosed sepsis or septic shock syndrome. Blood culture samples were collected in bactAlert media plus culture bottles and were incubated in BactAlert 3D semi-automated blood culture system; blood sample was collected for serum procalcitonin on immunoassay principle. Results: Out of 309, a total 87 blood cultures were positive and PCT was positive in 134 whereas 179 were PCT negative. In positive PCT, 63 were having bacterial growth in their blood culture while 71 were with negative blood culture. Although in total, 179 PCT were negative, only 16 were having bacterial growth in blood culture samples whereas all others revealed no growth that showed maximum number of positive blood cultures were having PCT positive but not all PCT positive demonstrated bacterial growth in blood culture suggesting that the bacteremia or sepsis can only be suspected with positive PCT. In addition, blood culture positive or negative results cannot be predicted by PCT value to make diagnostic confirmation of sepsis. Keywords: Procalcitonin (PCT), Blood culture, Sepsis, 95%CI; confidence interval, IQR; Interquartile range

Use of antibiotic-cement coated locking plates in the setting of periprosthetic infection and infected nonunion

IntroductionIn the setting of periprosthetic total hip and knee arthroplasty (THA/TKA) infection, plating of the femur may be necessary for fracture fixation, prophylactic fixation of the femur, poor bone quality, or infected femoral shaft nonunion. The purpose of this study was to investigate infection control rates and fracture healing in patients receiving antibiotic cement coated plates in the setting of infected nonunion and periprosthetic infections. MethodsWe retrospectively reviewed a series of ten patients who had an antibiotic coated plate placed in the setting of periprosthetic infection or infected nonunion with a minimum follow-up of six months. 80 g of Simplex bone cement (Stryker, Mahwah, NJ) were mixed with 4 g of powdered vancomycin and 4.8 g of powdered tobramycin and applied to a dynamic compression plate with locking screw guides in every hole. The antibiotic loaded cement was allowed to harden before implantation. Outcome measures were designed to assess for fracture healing defined as three out of four cortices united on radiographs along with bearing full weight without pain and evidence of infection control defined as normalized erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in the absence of antibiotic treatment with no clinical signs of infection. ResultsTen patients were treated with an antibiotic cement coated plate in the settings of infectious nonunion and periprosthetic infection and followed for an average of three years (mean 21.4 months, seven months to 61 months). Eight patients (80%) went on to successful control of infection after initial procedure. Two patients developed chronic drainage and had a second antibiotic spacer with antibiotic cement coated plate placed before the infection was controlled. All patients obtained successful control of infection at latest follow-up showing no clinical signs of infection, normalized laboratory markers, and negative culture results. There were no reported mechanical failures of the implant, fractures of the femur, or soft tissue complications. ConclusionAn antibiotic cement coated plating technique is a viable option for periprosthetic THA and TKA infections requiring plating of the femur or in patients with an infected nonunion.