Culture Fluid Research Articles

Zero incidence of culture-positive septic arthritis and low infection rate following ACLR with all-soft tissue quadriceps tendon autograft: An analysis of 1053 cases.

To evaluate the infection rate following anterior cruciate ligament reconstruction (ACLR) using all-soft tissue quadriceps tendon (ASTQT) autograft. All primary ASTQT autograft ACLRs within a single surgeon's prospectively collected database from 2011 to 2021 were retrospectively reviewed. No topical antibiotics were administered and no graft-soaking with antibiotics was performed during the study period. Patients who underwent multiligament knee reconstruction or a cartilage restoration procedure were excluded. Patients who underwent a subsequent procedure, including irrigation and debridement (I&D) of the knee joint, were included. Case-specific data, including fluid culture analysis, antibiotics (type, route of administration and duration), time to debridement and method of debridement, were collected. Descriptive statistics were utilized to analyze demographics, incidence and possible association between the need for I&D and concomitant meniscus surgery. Out of 1053 cases (mean age: 20.2 ± 6.3, 44.6% female), four patients (0.38%) (mean age: 18.5 ± 4.0, 25% female) underwent subsequent I&D (arthroscopic I&D only [n = 1], graft harvest site I&D only [n = 1], combined graft harvest site and arthroscopic I&D [n = 1] and tibia wound and arthroscopic I&D [n = 1]). There was no significant difference with regard to demographics. No joint fluid cultures returned positive; one wound culture returned positive for Methicillin-susceptible Staphylococcus aureus from their graft harvest site. The time to I&D ranged from 18 to 23 days. Concomitant meniscectomy or meniscal repair was not associated with requiring surgical I&D. All patients who underwent I&D were prescribed antibiotics for a minimum of 10 days and a maximum of 31 days (mean: 16.25 days). Three patients (75%) who underwent I&D ultimately returned to sport. One patient was lost to follow-up. ACL grafts were retained in all patients. The incidence of culture-positive septic arthritis following ASTQT autograft ACLR is 0%, while the overall need for I&D of 0.38% is low and not related to concomitant meniscal procedures or patient-specific factors. Level IV.

Case of delayed diagnosis of combined urogenita and pulmonary tuberculosis in a patient with abnormal uterine bleeding

According to the World Health Organization tuberculosis remains a global health issue for both adult and pediatric populations worldwide. Among women the peak incidence occurs during the active reproductive age, with pregnant women being 1.5–2 times more likely to be affected and experience more severe symptoms than non-pregnant women. In the Altai Region, the epidemiological situation of tuberculosis is characterized by instability, with the incidence rate among women reaching30.5 per 100 000 of the corresponding population in 2022. Delayed diagnosis and treatment can lead to serious complications, including fatal outcomes for both mother and fetus. This article describes a clinical observation of a case of urogenital and pulmonary tuberculosis diagnosed three months after premature abdominal delivery. The course of pregnancy was complicated by acute pleuritis at 13–14 weeks, however, negative results of bacteriological culture of pleural fluid led to the absence of specific tuberculosis treatment and the development of chronic subcompensated placental dysfunction. Three months after delivery, a 34-year-old patient was admitted to the gynecological department of the emergency hospital with abnormal uterine bleeding. The diagnosis was confirmed by histopathology of an endometrial sample revealing tuberculous granulomas without caseous necrosis with epithelioid giant cells of Pirogov – Langhans. Subsequently, generalized tuberculosis was diagnosed in the preterm infant. The negative impact of undiagnosed combined urogenital and pulmonary tuberculosis on the course and outcome of pregnancy is demonstrated, including the development of anemia, placental dysfunction, preterm delivery, puerperal complications, and adverse perinatal outcomes.

The occurrence of remitting seronegative symmetrical synovitis with pitting edema (RS3PE) after arthroplasty mimicking a periprosthetic joint infection: A case report and literature review.

As the elderly population grows, the number of joint arthroplasty surgeries is also increasing. Periprosthetic joint infection (PJI) is a postoperative complication that occurs in 1%-2% of the arthroplasties. Once it occurs, PJI is refractory to treatment. Similar symptoms of PJI, including joint synovitis and elevated body temperature, sometimes arise because of crystal arthritis, rheumatoid arthritis, or other inflammatory diseases. Precise diagnosis is essential for determining the optimal treatment strategy. An 81-year-old female patient with a history of bilateral knee arthroplasty presented with a high fever of 38 °C and was unable to walk due to swelling and pain in the bilateral lower extremities. Infectious conditions, such as cellulitis or PJI, were suspected. Imaging findings revealed bilateral knee joint synovitis with pitting edema around the lower extremities, and cultures of bilateral joint fluids were negative. No crystals were observed in the joint fluid. Laboratory data revealed highly elevated levels of inflammatory marker; however, antinuclear antibodies, including rheumatoid factor and cyclic citrullinated peptide, were not detected. Based on bilateral synovitis with pitting edema in the lower extremities, in addition to negative culture findings and normal antinuclear antibodies, the diagnosis of remitting seronegative symmetrical synovitis with pitting edema (RS3PE) was made. Steroid therapy was performed. The dose was gradually reduced, with the improvement of the symptoms. The inflammatory reaction promptly decreased and then normalized. With improved inflammation, the symptoms of pitting edema, pain in the bilateral lower extremities, and fluid effusion of the knee joints were reduced. She was able to walk without a cane, and her activities of daily living fully recovered. High fever and synovitis after joint arthroplasty do not necessarily indicate an infectious condition. Clinicians should be familiar with the occurrence of RS3PE, regardless of whether arthroplasty is performed.

Brain abscess caused by Mycobacterium tuberculosis in an immunocompetent patient: a case report and literature review.

Brain abscesses caused by Mycobacterium tuberculosis are rarely reported and are typically found in immunocompromised patients. The challenges in identifying the pathogen and the frequent delays in initiating appropriate therapy often result in a poor prognosis for patients. We herein report a rare case of a brain abscess caused by M. tuberculosis in a 63-year-old patient with a history of hypertension but no history of pulmonary tuberculosis. The patient was hospitalized twice because of worsening right upper limb weakness and speech difficulties. Both a pus culture and cerebrospinal fluid culture were negative. Ultimately, the diagnosis of M. tuberculosis infection was confirmed through next-generation sequencing and the tuberculosis-specific T-cell test (T-SPOT). The patient's symptoms improved following anti-tuberculosis treatment. This case highlights the importance of considering M. tuberculosis as a potential cause of brain abscesses, even in immunocompetent individuals, and underscores the need for early diagnosis for effective treatment.

Etiologies and Comorbidities of Meningitis Deaths in Children Under 5 Years in High-Mortality Settings: Insights from the CHAMPS Network in the Post-Pneumococcal Vaccine Era

BackgroundThe role of meningitis in causing deaths and in children under 5 is unclear, especially since widespread use of vaccines to prevent common causes of meningitis. Child Health and Mortality Prevention Surveillance (CHAMPS) uses post-mortem minimally invasive tissue sampling (MITS) and ante-mortem data to explore death causes. We aimed to assess meningitis’s contribution to mortality and identify causative pathogens in children under 5 within CHAMPS Network sites. MethodIn this observational study, we analyzed deaths in live-born children <5 years of age that occurred between December 16, 2016, and December 31, 2023, in CHAMPS catchments in six sub-Saharan African countries (Ethiopia, Kenya, Mali, Mozambique, Sierra Leone, South Africa) and Bangladesh. MITS was conducted within 24–72hours of death, including blood and cerebrospinal fluid (CSF) culture, multi-organism targeted nucleic acid amplification tests on blood, CSF and lung tissue, and histopathology of lung, liver and brain. Expert panels at each site reviewed data to attribute causes of death following ICD-10 standards. ResultMeningitis was in the causal pathway for 7.0% (270/3857) of deaths; in 4.8% (13/270) meningitis was considered the underlying condition. Neonates accounted for 65.9% (178/270) and infants or children 34.1% (92/270). Among neonatal meningitis deaths, 55.6% (99/178) occurred ≥72hours post-hospital admission; and common pathogens were Acinetobacter baumannii (49.5%, 49/99; mainly from South Africa) and Klebsiella pneumoniae (40.4%, 40/99). Forty-four percent (79/178) of neonatal meningitis deaths were community-associated, primarily due to K. pneumoniae (35.4%, 28/79) and Escherichia coli (13.9%, 11/79). Among infant and child meningitis deaths, 43.5% (40/92) occurred ≥72hours post-admission; and common pathogens were K. pneumoniae (42.5%,17/40) and A. baumannii (17.5%, 7/40). Among community-associated meningitis deaths in infants and children (56.5%, 52/92), Streptococcus pneumoniae (34.6%, 18/52) and K. pneumoniae (19.2%, 10/52) were common pathogens. Pathogen prevalence varied by region. ConclusionOur study highlights meningitis as a significant contributor to under-5 mortality in low-middle-income countries. The prominent role of K. pneumoniae and A. baumannii, particularly in healthcare settings and specific regions, highlights the need for better infection control, targeted interventions, and more effective treatment strategies.

Highly selective split intein method for efficient separation and purification of recombinant therapeutic proteins from mammalian cell culture fluid

Biologics and vaccines have been successfully developed over the last few decades to treat many diseases. Each of these drugs must be highly purified for clinical use. Monoclonal antibodies (mAbs), the dominant therapeutic modality on the market, can be easily purified using the standard Protein A affinity platform. However, no generally applicable affinity platforms are available for the manufacture of other therapeutic proteins for clinical use. Thus, multicolumn chromatography processes for widely being used for product purification. These processes demand significant optimization to meet desired product quality attributes, where each step also decreases final yields. In this work, we demonstrate the novel self-removing iCapTagTM affinity tag, which provides a new platform for capturing, concentrating, and purifying recombinant proteins. Importantly, this system provides a tagless target protein, which is suitable for research and clinical use, where the only requirement for tag removal is a small change in buffer pH. No additional proteins, reagents or cofactors are required. We also present case studies demonstrating the use of iCapTagTM for highly efficient purification of untagged interferon alpha 2b, the ML39 single chain variable fragment (scFv), and the receptor binding domain (RBD) of SARS-CoV-2 spike protein. These proteins were expressed and secreted by Expi293 cells with the self-removing tag fused to their N-terminus. We were able to obtain highly pure (> 99%) tagless protein in a single purification step with high clearance of host cell DNA, tagged precursor, higher and lower molecular weight impurities. Based on these preliminary results, we propose the iCapTagTM as a universal capture platform for diverse classes of recombinant therapeutic proteins.

Clinical Features Associated With Return to Pre-endophthalmitis Visual Acuity Following Presumed Infectious Endophthalmitis.

This study aimed to investigate clinical characteristics associated with return to pre-endophthalmitis visual acuity (VA) following treatment for presumed infectious endophthalmitis. This was a retrospective study of 74 eyes with endophthalmitis and VA recorded ≤ 12 weeks before presentation and 6 months after presentation between 2009 and 2018. Thirty-six of 74 eyes (49%) returned to preendophthalmitis VA. Eyes with a positive intraocular fluid culture had 71.5% lower odds of returning to pre-endophthalmitis VA. Nine of 10 eyes (90%) treated with initial pars plana vitrectomy failed to return to pre-endophthalmitis VA. Endophthalmitis following cataract surgery was a characteristic of eyes that returned to pre-endophthalmitis VA. Symptom duration, time to presentation, and treatment with systemic corticosteroids were not significant predictors of visual recovery. Just under 50% of eyes with presumed infectious endophthalmitis returned to preendophthalmitis VA. A positive intraocular culture is associated with failure to return to pre-endophthalmitis VA. [Ophthalmic Surg Lasers Imaging Retina 2024;55:XX-XX.].

Streptococcus equi Subspecies zooepidemicus Endocarditis and Meningitis in a 62-Year-Old Horse Rider Patient: A Case Report and Literature Review

The present article presents a case report and literature review concerning the Streptococcus equi subspecies zooepidemicus (SEZ), a rare zoonotic pathogen in humans. The case involves a 62-year-old man with no prior heart disease, presenting with endocarditis, pneumonia, and meningitis following close contact with a horse. The patient underwent urgent aortic valve replacement due to severe valvular damage caused by the infection. Blood and cerebrospinal fluid cultures confirmed the presence of SEZ, and the patient was treated with a combination of antibiotics, followed by a successful step-down to oral therapy using linezolid. A review of 25 additional Streptococcus equi endocarditis cases highlights the rarity of the condition, its association with animal contact, and its tendency to cause multi-site infections, such as pneumonia and meningitis. Early diagnosis, appropriate antibiotic therapy, and, in severe cases, surgical intervention are critical for a favorable outcome. This report emphasizes the importance of recognizing zoonotic infections in at-risk populations and the potential need for public health surveillance in these scenarios.

Severe co-infection caused by difficult-to-diagnose hypermucoviscous Klebsiella pneumoniae K1-ST82 in a patient with COVID-19: a case report

BackgroundCo-infection with Klebsiella pneumoniae presents a significant concern in hospitalized patients with coronavirus disease (COVID-19), increasing the risk of severe disease progression. Hypervirulent (hv) and hypermucoviscous (hm) K. pneumoniae (Kp) has gained prominence in Asia due to its capacity to cause invasive community-acquired infections. However, recognition of hvKp/hmKp co-infections in the context of COVID-19 remains limited. We report a severe case of rapidly progressing co-infection with hmKp exhibiting “difficult-to-diagnose” phenotypes in a hospitalized patient with COVID-19.Case presentationA 61-year-old woman with COVID-19 initially exhibited mild symptoms resembling the common cold. However, her condition rapidly deteriorated over 7 days, leading to hospital admission with the development of dyspnea. The patient required supplemental oxygen, antibiotic treatment, and mechanical ventilation. Gram-negative bacteria with atypical phenotypes were isolated from alveolar lavage fluid and blood cultures. Both strains formed small, glossy, non-lactose-fermenting colonies on clinically relevant media and were susceptible to ampicillin. Conventional biochemical tests failed to identify the Enterobacteriales strains owing to the urease-negative phenotype. Consequently, the identification of K. pneumoniae was difficult until matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis was performed. A positive string test indicated mucoviscosity, but with variability in the material used for stretching colonies. Whole-genome sequencing performed on the MiSeq and GridION platforms revealed the blood-derived strain JARB-RN-0063 as belonging to serotype K1 and sequence type (ST) 82. The hvKp-associated genes rmpA and iroCD were located on a 5.0-Mb chromosome, and iucABCD-iutA was identified on a 217.9-kb IncFIB(K)/IncR-type plasmid. Therefore, JARB-RN-0063 was genetically classified as hvKp with a Kleborate virulence score of 3. The intrinsic penicillinase gene blaSHV was defective owing to an IS1F element insertion, resulting in the strain being atypically susceptible to ampicillin.ConclusionsThis is the first case of severe COVID-19-associated co-infection with a difficult-to-diagnose K. penummoniae strain. Notably, co-infection by the hmKp K1-ST82 clone exhibited atypical phenotypes, including stunted growth, non-lactose fermentation, urease-negative reaction, ampicillin susceptibility, and abnormal mucoviscosity, posing diagnostic challenges for clinical laboratories and impedes the identification of hvKp/hmKp. Delayed identification may worsen patient outcomes, highlighting the need for increased clinical awareness of such difficult-to-diagnose clones to prevent deterioration.

Improving the microbiological diagnosis of fracture-related infection and prosthetic joint infection through culturing sonication fluid in Bactec blood culture bottles.

Sonication of surgically removed implants appears to optimize the microbiological diagnosis in orthopedic implant-associated infections (OIAI). However, reports of infection with negative cultures can still reach high rates. A study evaluating the inoculation of sonication fluid into blood culture bottles (SFBCB) in patients with fracture-related infection (FRI) and prosthetic joint infection (PJI) is necessary. This study compared the accuracy SFBCB over the conventional sonication fluid cultures (CSFC) and tissue culture (TC). Consecutive patients who underwent implant removal surgeries due to any reason had their implants sonicated according to standardized method. Definitions of PJI and FRI were based upon criteria by European Bone and Joint Infection Society (EBJIS) and Metsemakers, respectively. Between three to five intraoperative tissue samples were processed. The implant`s sonication fluid was seeded onto sheep blood agar, chocolate agar, thioglycolate broth and on tryptic soy broth for CSFC, while was also inoculated into blood culture bottles and incubated in the automated system during 5 days for SFBCB. Overall, 74 patients were analyzed, of which 57 with OIAI (48 FRI and 09 PJI) and 17 aseptic failures (03 arthroplasties and 14 osteosynthesis). Interestingly, SFBCB demonstrated significantly higher sensitivity compared to CSFC (96.5% [95% CI, 88-100] vs. 78.9% [95% CI, 66-89], p = 0.004), and to TC (96.5% [95% CI, 88-100], vs. 57.9% [95% CI, 44-71], p < 0.001), whereas there were no significant differences in specificity between the three methods. In comparison to CSFC and TC, SFBCB improved sensitivity for diagnosing OIAI without compromising specificity.

Emphysematous pyelonephritis caused by Raoultella ornithinolytica: a case report

BackgroundEmphysematous pyelonephritis is a rare and severe urinary tract infection that is potentially life-threatening and easily progresses to septic shock. In this report, we present a unique case of emphysematous pyelonephritis caused by Raoultella ornithinolytica.Case presentationAn 86-year-old man presented with severe back pain of 3 days’ duration. He had a history of hypertension and diabetes for more than 20 years, and his infection indicators and serum creatinine were elevated. Abdominal computed tomography revealed an abnormal gas shadow around his right kidney and the anterior edge of his right psoas muscle. Consequently, he was initially diagnosed with emphysematous pyelonephritis. There was no evidence of nephrolithiasis or other anatomical or structural abnormalities that could have precipitated this focal renal infection. Both blood and drainage fluid cultures revealed R. ornithinolytica. After early anti-infection treatment, percutaneous drainage and moderate control of blood glucose, the patient gradually recovered.ConclusionsEmphysematous pyelonephritis caused by R. ornithinolytica is rare but has a high drug resistance rate potentially and may cause severe infections. Early diagnosis, prompt use of antibiotics that are sensitive to the organism, and decompression drainage could be the key to treatment.

Comparison of DNA extraction procedures for detection of Mycoplasma bovis directly from extended bovine semen straw samples using a commercial M. bovis PCR

BackgroundMycoplasma bovis is a global pathogen of cattle but was detected for the first time in New Zealand in 2017, triggering a response under their Biosecurity Act as an “unwanted organism”. Following a lengthy eradication campaign, the Ministry of Primary Industries (MPI) now requires all bovine semen destined for export to New Zealand to be screened with an M. bovis-specific real-time PCR (rtPCR) compliant with amended import health standard (IHS) test requirements aimed at preventing the accidental importation of M. bovis. The standard stipulates that semen samples cannot be centrifuged prior to DNA extraction. To comply with these strict requirements, one of the listed tests was validated together with different DNA preparation steps and compared with existing in-house procedures. DNA was extracted from semen straws using the current in-house semi-automated platform procedures for processing culture, tissue and body fluid sample submissions and was compared with the stipulated test requirements. DNA from centrifuged and unspun semen samples spiked with M. bovis was also compared.ResultsThe rtPCR had a sensitivity and specificity of 100% (95% confidence interval = 79–100% and 74–100%, respectively) when testing DNA from other Mycoplasma species or bovine semen spiked with the latter, with a high level of repeatability for within- and between- run replicates. The consistent limit of detection was 0.001 pg/µl M. bovis DNA and between 5.3 × 102 and 7.5 × 102 CFU/ml M. bovis when artificially spiked in semen. DNA extracted using the KingFisher Flex was detected with lower Cq values than the Maxwell 16, but the comparable improvements in sensitivity were mainly associated with non-centrifuged samples (p < 0.001). None of the procedures tested impeded the detection sensitivity of M. bovis in the presence of competitor organisms Acholeplasma laidlawii, Mycoplasma bovigenitalium and Ureaplasma diversum, confirming M. bovis specificity of the polC target.ConclusionsUnder the experimental conditions applied, this rtPCR test efficiently detected M. bovis in extended bovine semen straw samples from DNA extracted using both semi-automated extraction platforms, irrespective of prior centrifugation of extended semen.

High keratinase and other types of hydrolase activity of the new strain of Bacillus paralicheniformis.

Keratinases, a subclass of proteases, are used to degrade keratin thereby forming peptones and free amino acids. Bacillus paralicheniformis strain T7 was isolated from soil and exhibited high keratinase, protease, collagenase, amylase, xylanase, lipase, and phosphatase activities. Keratinases of the strain showed maximum activity at 70°C and pH 9.0 as well as high thermal stability. A mass-spectrometric analysis identified seven peptidases with molecular masses of 26.8-154.8 kDa in the secretory proteome. These peptidases are members of S8 and S41 serine peptidase families and of M14, M42, and M55 metallopeptidase families. Additionally, α-amylase (55.2 kDa), alkaline phosphatase (59.8 kDa), and esterase (26.8 kDa) were detected. The strong keratinolytic properties of the strain were confirmed by degradation of chicken and goose feathers, which got completely hydrolyzed within 4 days. Submerged fermentation by strain B. paralicheniformis T7 was carried out in a pilot bioreactor, where the highest keratinase production was noted after 19 h of cultivation. After the fermentation, in the culture fluid, the keratinase activity toward keratin azure was 63.6 ± 5.8 U/mL. The protease activity against azocasein was 715.7 ± 40.2 U/mL. The possibility of obtaining enzyme preparations in liquid and powder form was demonstrated, and their comparative characteristics are given. In the concentrate, the keratinase, protease, α-amylase, phosphatase, and esterase/lipase activities were 2,656.7 ± 170.4, 29,886.7 ± 642.9, 176.1 ± 16.3, 23.9 ± 1.8, and 510.9 ± 12.2 U/mL, respectively. In the lyophilizate, these activities were 57,733.3 ± 8,911.4, 567,066.7 ± 4,822.2, 2,823.0 ± 266.8, 364.2 ± 74.8, and 17,618.0 ± 610.3 U/g, respectively. In the preparation obtained by air flow drying at 55°C, these activities were 53,466.7 ± 757.2, 585,333.3 ± 4,277.1, 2,395.8 ± 893.7, 416.7 ± 52.4, and 15,328.1 ± 528.6 U/g, respectively. The results show high potential of B. paralicheniformis strain T7 as a producer of keratinases and other enzymes for applications in agricultural raw materials and technologies for processing of keratin-containing animal waste.

Features of proinflammatory activation of macrophages in patients with rheumatoid arthritis and systemic lupus erythematosus

Autoimmune rheumatic diseases (ARDs) are chronic pathological conditions that arise from an abnormal immune response and are accompanied by systemic inflammation. The most common ARDs include rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). The exact pathogenesis of ARDs remains unclear, but the complex influence of genetic, immunological and external environmental factors leads to the occurrence and further progression of ARDs. It has been shown that the cause of chronic inflammation may be proinflammatory activation of macrophages, in which an increase in the secretion of cytokines is observed. The aim of this study was to evaluate the inflammatory response of macrophages in patients with RA, SLE and SSc. Materials and methods. The study included 143 participants: 47 patients with RA, 45 patients with SLE, 34 patients with SSc, and 17 people without ARDs and other chronic diseases. Isolation of a primary culture of monocytes was carried out by centrifugation in a ficoll gradient using magnetic separation from the whole blood of study participants. Lipopolysaccharide (LPS) was added to stimulate cells along the proinflammatory pathway. Cell cultivation was carried out for 24 hours. Determination of basal and LPS-stimulated secretion of IL-8 by macrophages was carried out in the culture fluid using an enzyme-linked immunosorbent assay (ELISA). Proinflammatory activation of macrophages was calculated as the ratio of LPS-stimulated and basal IL-8 secretion. Research results. Basal secretion of IL-8 by macrophages was statistically significantly higher in the groups of patients with RA and SSc compared with the SLE and control groups. LPS-stimulated secretion of IL-8 by macrophages in the SSc group had statistically higher values compared to the RA and SLE groups. Proinflammatory activation of macrophages was reduced in the group of patients with RA compared to patients with SLE and the control group, and was also statistically significantly lower in patients with SSc compared to the control group.

43 Etiology of community-acquired bacterial meningitis in children seen in the emergency department in Canada

Abstract Background Bacterial meningitis poses a significant threat to paediatric health, resulting in substantial morbidity and mortality in children. Though previous studies have delineated the causative agents behind community-acquired meningitis, recent vaccination initiatives may have reshaped its underlying etiology. Objectives This study aimed to identify the bacteria responsible for community-acquired bacterial meningitis in children in Canada. Design/Methods This was a retrospective cohort study including children aged 1 day-18 years with confirmed bacterial meningitis, evaluated at a tertiary-care, Canadian emergency department between July 1st 2014 and December 31st 2022. The primary outcome was the pathogen identified. Other variables of interest were mortality, complications, age, sex, and diagnostic method. Medical charts were identified via the hospital’s archives and reviewed by a single co-author. A random sample of 20 (23%) medical charts were independently reviewed by a second co-author to assess inter-rater reliability. We set a target of evaluating at least 50 cases to allow narrow confidence intervals (+/- 13%) for proportions. Results All variables showed excellent inter-rater reliability with Kappa scores and intraclass correlation coefficients higher than 0.60. All 79 eligible cases were included. The main causal agents were Group B Streptococcus (GBS) (n=20; 25%), Streptococcus pneumoniae (n=16; 20%), Neisseria meningitidis (n=16; 20%) and Haemophilus influenzae (n=9; 11%). Etiology exhibited age-dependent variations, with 85% of GBS and 100% of E. coli infections identified in children under two months, while all pneumococcal and Group A Streptococcus cases were in children older than six months. All children infected by S. pneumoniae were vaccinated against pneumococcal infection but the serotype was not covered by vaccination in 7/8 infections. All children with N. meningitidis were either too young to be vaccinated (n=10) or infected by a serotype not covered by the vaccine. Six (7%) patients died and 29 (34%) suffered complications, including hearing impairment (n=5), cerebral ischemia (n=4), seizures (n=4), and subdural abscess (n=3). Fifty-nine bacterias were identified by cerebrospinal fluid culture, 13 by PCR and 7 by both methods. Conclusion GBS is the leading etiology of paediatric community-acquired bacterial meningitis in Canada. Causal agents of bacterial meningitis vary greatly by age. Future studies should work on improving the serotype spectrum of vaccines, prophylaxis in mothers who are GBS carriers, and use of PCR as a diagnostic tool for timely clinical interventions.

Application of a metatranscriptomics technology, CSI-Dx, for the detection of pathogens associated with prosthetic joint infections

Preoperative identification of causal organism(s) is crucial for effective prosthetic joint infection treatment. Herein, we explore the clinical application of a novel metatranscriptomic (MT) workflow, CSI-Dx, to detect pathogens associated with prosthetic joint infection. MT provides insight into transcriptionally active microbes, overcoming limitations of culture-based and available molecular methods. This study included 340 human synovial fluid specimens subjected to CSI-Dx and traditional culture-based methods. Exploratory analyses were conducted to determine sensitivity and specificity of CSI-Dx for detecting clinically-relevant taxa. Our findings provide insights into the active microbial community composition of synovial fluid from arthroplasty patients and demonstrate the potential clinical utility of CSI-Dx for aiding prosthetic joint infection diagnosis. This approach offers potential for improved sensitivity and acceptable specificity compared to synovial fluid culture, enabling detection of culturable and non-culturable microorganisms. Furthermore, CSI-Dx provides valuable information on antimicrobial resistance gene expression. While further optimization is needed, integrating metatranscriptomic technologies like CSI-Dx into routine clinical practice can revolutionize prosthetic joint infection diagnosis by offering a comprehensive and active snapshot of associated pathogens.

Data-driven optimization of the in silico design of ionic liquids as interfacial cell culture fluids

ABSTRACT As an alternative to conventional plastic dishes, the interface between water-immiscible hydrophobic fluids, such as perfluorocarbons and silicones, permits cell adhesion and growth. Thus, it is expected to replace the petroleum-derived products in a sustainable society. However, most hydrophobic fluids are cytotoxic, which limits the range of mechanical and chemical cues exposed to the cells. Using a data-driven approach, this study aimed to identify non-cytotoxic ionic liquids (ILs) as fluid culture platforms to take advantage of their ‘designer’ nature for broadening the possible physicochemical ranges exposed to cells and their repeated use owing to their high heat stability before their biological applications. The new candidates within the readily synthesize ammonium-type ILs were identified through the active cycle of regression and a limited number of cytotoxicity tests. Structure – cytotoxicity analysis indicated that the presence of multiple long alkyl branches was critical for low cytotoxicity. Particularly, we successfully cultured human mesenchymal stem cells (hMSCs) at the trihexylethylammonium trifluoromethylsulfonylimide interface and repeated their use after solvent extraction and heat sterilization. This study identified non-cytotoxic ILs that fulfill plastics’ 3 R ( R educe, R ecycle, and R eplace) requirements and opens new avenues for hMSC fate manipulation through mechanotransduction.

Etiology of community-acquired bacterial meningitis in children at a tertiary-care centre in Montreal, Canada

Abstract Objectives This study aimed to identify the bacteria responsible for community-acquired bacterial meningitis in infants and children. Methods This was a retrospective cohort study including children aged 1 day to 18 years with confirmed bacterial meningitis, evaluated at a tertiary-care, Canadian emergency department between 2014 and 2022. The primary outcome was the pathogen identified. Other variables of interest were complications, age, and diagnostic method. Medical charts were reviewed by a co-investigator and 25% were assessed in duplicate. Results All 79 eligible cases were included. The main causal agents were Group B Streptococcus (GBS) (n = 20; 25%), Streptococcus pneumoniae (n = 16; 20%), Neisseria meningitidis (n = 16; 20%), and Haemophilus influenzae (n = 9; 11%). Etiology exhibited age-dependent variations, with 85% of GBS and 100% of Escherichia coli infections in children under 2 months. All pneumococcal and Group A Streptococcus cases were in children older than 6 months. All children infected by S. pneumoniae were vaccinated but the serotype was not covered by vaccination in 7/8 infections. All children with N. meningitidis were either too young to be vaccinated (n = 10) or infected by a serotype not covered by the given vaccine. Fifty-five bacteria were identified by cerebrospinal fluid culture, 17 by Polymerase Chain Reaction (PCR), and 7 by both methods. Conclusion GBS is now the leading etiology of paediatric community-acquired bacterial meningitis at our centre. The etiology of bacterial meningitis varies greatly by age. Future studies should focus on improving the serotype spectrum of vaccines, identifying strategies to lower GBS infection, and improving the use of PCR as a diagnostic tool.

Raman spectroscopy for monitoring free sulfhydryl formation during monoclonal antibody manufacturing

During production, harvested cell culture fluid (HCCF) can degrade due to reductases breaking interchain disulfide bonds, forming low molecular weight (LMW) impurities that contain free sulfhydryl and high molecular weight (HMW) impurities through disulfide shuffling. Thus, detecting and quantifying the free sulfhydryl increase in HCCF is critical. Herein, Raman spectroscopy is implemented as a process analytical technology, and multivariate data analysis is applied to characterize and quantify sulfhydryl formation in HCCF with disulfide-containing indicator molecules. Raman spectra qualitatively probe the presence or absence of disulfide bond breakage in antibodies, consistent with offline non-reduced capillary electrophoresis sodium dodecyl sulfate results. Between two antibodies studied, mAb A was identified for a higher risk of antibody reduction where sulfhydryl formation was observed within 16 h, while mAb B did not show similar concerns even after 1 week. The offline measurement of redox potential is below –100 mV in HCCF for mAb A, while the stable mAb B HCCF shows redox potentials above +20 mV. A multivariate partial least squares (PLS) model for quantification is developed using an offline free sulfhydryl assay, applying Raman spectra to predict free sulfhydryl concentration with high accuracy (R2 > 0.98) and expected mean error of 0.677 mM from the offline Ellman’s Assay. This work confirms the use of Raman PAT to monitor real-time disulfide reduction, enabling improvements to process understanding and product quality.

Efficacy of Endovascular Glue Embolization in Treating Ruptured Intracranial Mycotic Aneurysms: A Single Center Experience.

Intracranial mycotic aneurysms (IMAs), rare and often life-threatening, result from arterial wall infections typically caused by bacteria such as Staphylococcus and Streptococcus. The standard treatment for ruptured aneurysms is not well-defined and often individualized. This study investigates the efficacy of endovascular glue embolization in managing ruptured IMAs, based on our center's experience. A retrospective analysis was conducted for ruptured IMAs treated with glue embolization between January 2016 and December 2023. The procedure involved aneurysm sac and parent vessel occlusion with glue delivery. Data included patient demographics, clinical presentations, and neuroimaging. Clinical outcomes were assessed using the modified Rankin scale (mRS) at 3 months, and angiographic follow-up was conducted at 6 months. The study included 28 patients, predominantly male (64.3%), with a mean age of 48 years. Headache was the primary symptom in 92.9% of cases, and positive blood/cerebro spinal fluid cultures were found in 82.14% of cases. All aneurysms were located in the distal circulation, primarily in the anterior circulation system. Glue embolization was successfully performed in all cases, achieving complete aneurysm sac and parent vessel obliteration. Follow-up at 3 months indicated mRS scores of 0 or 1 in 96.5% of cases. Six-month angiographic follow-up showed no aneurysm regrowth or new formations. Endovascular glue embolization demonstrated high efficacy and safety in treating ruptured IMAs, with a 100% obliteration rate and favorable clinical outcomes in this single-center experience. Despite limitations such as its retrospective design and small sample size, the study supports glue embolization as a viable, less invasive alternative to traditional surgery. Further comparative studies are needed to confirm these findings and refine treatment approaches.