Negative Bacterial Cultures Research Articles

Primary osteosarcoma of the breast during lactation: a case report and literature review

Primary osteosarcoma of the breast (POB) is an aggressive and exceedingly rare tumor, and cases with onset during lactation are extremely rare. The exact mechanism of POB development remains unclear. They may originate from totipotent mesenchymal cells in the breast stroma or may be the result of neoplastic transformation of prior breast lesions. Here, we present the case of a 40-year-old Chinese woman who was found with a palpable tumor measuring approximately 3 cm in diameter in her right breast while breastfeeding 4 months post-partum. The lactating woman was misdiagnosed with lactational mastitis during her initial visit to a community hospital. However, due to negative bacterial cultures and ineffective anti-infective treatment, later on the patient was taken to a more advanced hospital where a tissue biopsy was taken. The superior hospital considered that it might be a malignant tumor and performed local excision of the breast mass, leading to a final pathological diagnosis of POB. This is the first reported case of primary osteosarcoma during breastfeeding. We hope that this case report will improve readers’ understanding of the diagnosis and differential diagnosis of POB, especially for patients with atypical clinical symptoms and imaging findings, which should not be taken lightly.

Challenges of Congenital HHV6 Infection Diagnosis and Treatment: Two Case Reports and Literature Review

Introduction: Congenital human herpesvirus 6 (HHV6) infection occurs in 1% of the general population and may result from the transmission of an inherited chromosomally integrated HHV6 (iciHHV6) or transplacental infection. It is mostly asymptomatic. Case reports: Case 1: a 29th-week-old female preterm newborn, admitted to the neonatal intensive care unit, became clinically unstable and irritable on the 20th day of hospitalization. Cranial ultrasound, revealed a significant posthemorrhagic tetraventricular dilation, with signs of ventriculitis. Investigations revealed HHV6 positivity on cerebrospinal fluid polymerase chain reaction multiplex panel testing and HHV6-DNA high viral loads in plasma samples. Case 2: a female late preterm newborn was admitted to the neonatal intensive care unit due to early-onset sepsis. Investigations revealed group B streptococcus positive blood cultures and cerebrospinal fluid HHV6 positivity on polymerase chain reaction multiplex panel testing, with negative bacterial culture. After 3 days of adequate antibiotic treatment, she maintained persistent moaning, which motivated a cranial ultrasound, revealing mild brain edema. Clinical improvement was observed only after beginning antiviral treatment in both newborns. Due to the persistency of high viral loads in both cases, despite antiviral treatment and clinical improvement, an iciHHV6 was suspected and posteriorly confirmed. Discussion/conclusion: Congenital iciHHV6 infection diagnosis is challenging because the presence of an iciHHV6 results in persistently high viral loads, even in the absence of active infection. Only a few diagnostic techniques can confirm active replication; unfortunately, these are not available in most countries. The decision to initiate antiviral treatment should be based on clinical judgment. Better ways for the diagnosis of active infection are needed.

Synthesis and application of WO3/PVA nano composite for antibacterial and thermal insulation

Abstract Insulation of glass material is very important for sustainable environment in this real world without compromising its primary function. The aim of this research is to provide robust solution by synthesis the Nano Tungsten trioxide particles via the chemical precipitation method. Developed WO3 NPs Characterized by using x-ray diffraction for; crystal structure, compound composition, and average crystalline size. Scanning Electron Microscopy (SEM) employed to analyze the shape and dimensions of the WO3 NPs. Explored the potential thermal insulation and antibacterial attributes by coating 1%, 3%, 5% and 7% concentration of synthesized WO3 NPs in polyvinyl alcohol onto a sodium silicate glass substrate (4 × 4 inches; 2 mm thickness) by using 50 μm doctor blade. WO3/PVA solution showed the antibacterial properties measure by agar disc diffusion method on gram positive and negative bacterial culture S. coli and E. bacterial culture and the obtained results after incubation were showing very minor zone of incubation as compare to previous studies. Thermal insulation of coated glass samples were increased with % of WO3 NPs concentration in PVA and validate by significant coefficient of determination (R2 = 0.985).

Rocky Mountain Spotted Fever Encephalitis and "Starry Sky" Pattern on MRI: A Case Report.

Rocky Mountain Spotted Fever (RMSF) is a tick-borne disease caused by Rickettsia rickettsii (R. rickettsii). RMSF presents after a tick bite with fever, rash, and headache but can also cause more serious neurological manifestations. We report a case of RMSF encephalitis presenting with altered sensorium and rapid progression to coma, fever, and petechial rash, and an magnetic resonance imaging (MRI) brain notable for a "starry sky" pattern. A 61-year-old woman presented with confusion and fever and was diagnosed with a urinary tract infection. Two days later, she became comatose. MRI brain revealed lacunar infarcts in the right centrum semiovale and splenium of the corpus callosum. Lumbar puncture was notable for neutrophilic pleocytosis and elevated protein with negative bacterial and viral cultures. Empiric meningitis therapy was initiated, and she was transferred to our institution. On transfer, she was febrile, comatose, and had a diffuse petechial rash. Repeat MRI brain demonstrated diffuse, innumerable punctate foci of diffusion restriction with susceptibility-weighted signal attenuation throughout cerebral hemispheres in a "starry sky" pattern. Skin biopsy revealed perivascular lymphocytic infiltrates. Serologic RSMF antibody titers were obtained, and doxycycline was initiated for presumed RMSF encephalitis. The family opted to pursue palliative measures, given no clinical improvement. RSMF titers and postmortem PCR from brain tissue were positive for R. rickettsii. This case report highlights the clinical presentation of RMSF encephalitis. RMSF encephalitis should be suspected in a patient presenting with encephalopathy, fever, petechial rash, and MRI brain findings of diffuse punctate foci of diffusion restriction and susceptibility-weighted signal attenuation in a "starry-sky" pattern.

Respiratory viral infections in children with cancer and febrile neutropenia and children undergoing hematopoietic stem cell transplantation.

The scope of this review is to understand the epidemiology and potential role of respiratory viral infections in children with cancer and febrile neutropenia, as well as in children, undergoing hematopoietic stem cell transplantation. Early detection of respiratory viral infections through molecular diagnostic techniques has allowed recent randomized clinical studies to advance the possibility of more rational use of antimicrobials in this susceptible population. Progress has been made in the early detection of respiratory viruses in episodes of fever and neutropenia in children with cancer. In selected patients who meet specific clinical safety criteria and have negative bacterial cultures, it has been possible to safely and effectively discontinue antimicrobials. This has been validated in recent randomized clinical studies. However, more evidence is still needed for a similar indication in children, undergoing hematopoietic stem cell transplantation with viral respiratory infection episodes. Understanding the role of respiratory viral infections in populations of immunocompromised children may contribute to a more rational use of antimicrobials and, in the near future, may help to decrease antimicrobial resistance in this susceptible population.

Perichondritis of the auricle: bacterial or fungal? (A case series)

BackgroundSuppurative perichondritis of the auricle is a common disease that can easily cause malformations if it develops into an uncontrolled infection. In nearly half of the cases, otolaryngologists cannot identify the pathogens involved.Case presentationIn the present work, we described two cases of pyogenic perichondritis, with negative on conventional culture. However, using metagenomic next-generation sequencing (mNGS), we detected fungal infections in the patients and after the patients were given anti-fungal treatment, the patients achieved a good prognosis.ConclusionsThese cases highlighted the possibility that fungi might be the involved pathogens in patients who have had multiple negative bacterial cultures, and mNGS should be applied in these cases. mNGS could be used as a supplement to traditional culture methods.

Evaluation of a multiplex-qPCR for paediatric pleural empyema-An observational study in hospitalised children.

Pleural empyema is a serious complication of pneumonia in children. Negative bacterial cultures commonly impede optimal antibiotic therapy. To improve bacterial identification, we developed a molecular assay and evaluated its performance compared with bacterial culture. Our multiplex-quantitative PCR to detect Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus and Haemophilus influenzae was assessed using bacterial genomic DNA and laboratory-prepared samples (n = 267). To evaluate clinical performance, we conducted the Molecular Assessment of Thoracic Empyema (MATE) observational study, enrolling children hospitalised with empyema. Pleural fluids were tested by bacterial culture and multiplex-qPCR, and performance determined using a study gold standard. We determined clinical sensitivity and time-to-organism-identification to assess the potential of the multiplex-qPCR to reduce the duration of empiric untargeted antibiotic therapy. Using spiked samples, the multiplex-qPCR demonstrated 213/215 (99.1%) sensitivity and 52/52 (100%) specificity for all organisms. During May 2019-March 2023, 100 children were enrolled in the MATE study; median age was 3.9 years (IQR 2-5.6). A bacterial pathogen was identified in 90/100 (90%) specimens by multiplex-qPCR, and 24/100 (24%) by bacterial culture (P <0.001). Multiplex-qPCR identified a bacterial cause in 68/76 (90%) culture-negative specimens. S. pneumoniae was the most common pathogen, identified in 67/100 (67%) specimens. We estimate our multiplex-qPCR would have reduced the duration of untargeted antibiotic therapy in 61% of cases by a median 20 days (IQR 17.5-23, range 1-55). Multiplex-qPCR significantly increased pathogen detection compared with culture and may allow for reducing the duration of untargeted antibiotic therapy.

Clinical relevance of positive intraoperative bacterial culture in tibial plateau leveling osteotomy in dogs: a retrospective study

BackgroundTibial plateau leveling osteotomy (TPLO) belongs to the most frequently used surgical method for the treatment of cranial cruciate ligament rupture in dogs. Surgical site infection (SSI) is one of the possible postoperative complications. The aim of this study was to evaluate the diagnostic value of intraoperative bacterial culture as a tool for the detection of intraoperative bacterial contamination progressing to infection development in canine TPLO. Electronic patient records from dogs who underwent TPLO between January 2018 to December 2020 were retrospectively reviewed. Intraoperative bacterial culture results, used antimicrobial drugs and presence of SSI were recorded.ResultsNinety-eight dogs were included in the study. SSI rate was 10.2%. All dogs who developed SSI (n = 10) had negative intraoperative bacterial cultures. None of the dogs with positive intraoperative bacterial culture (n = 6) developed SSI. The most cultured bacteria causing SSI was Staphylococcus pseudintermedius (n = 4).ConclusionsIntraoperative bacterial culture in dogs undergoing TPLO is not suitable as a predictor of surgical site infection.

The footprint of SARS-COV-2 infection in neonatal late sepsis

BackgroundPredicting and finding the viral agents responsible for neonatal late-sepsis has always been challenging.MethodIn this cross-sectional study, which has been done from September 2020 to December 2022, 145 hospitalized neonates suspected to late-onset sepsis alongside routine sepsis workup, were also evaluated for severe acute respiratory syndrome-coronavirus-2 (SARS-COV-2) infection, by nasopharyngeal real-time polymerase chain reaction (RT-PCR) or serological tests.Result145 neonates including 81 girls and 64 boys with a mean age of 12.3 ± 5.9 days and an average hospitalization stay of 23.1 ± 15.4 days were enrolled in the study. While 76.6% of them had negative bacterial culture, 63 patients (43.4%) showed evidence of SARS-COV-2 infection in RT-PCR or serology tests. None of the underlying factors including gender, age, and laboratory investigation had a significant relationship with SARS-COV-2 infection. Similarly, the outcomes of death and length of hospitalization were not different between the two groups with positive and negative SARS-COV-2 RT-PCR (P < 0.05). There was only a significant relationship between radiological changes including reticulonodular pattern, consolidation, pleural effusion, and different types of infiltrations and SARS-COV2 infection.ConclusionConsidering the widespread of coronavirus disease 2019 (COVID-19) in newborns, it seems logical to investigate the SARS-COV-2 infection in late-sepsis.

Long-Term Outcomes Following Single-Stage Reamed Intramedullary Exchange Nailing in Apparently Aseptic Femoral Shaft Nonunion with Unsuspected Proof of Bacteria.

Background: The aim of this study was to evaluate detection rates and risk factors for unsuspected proof of bacteria, as well as clinical and radiologic outcomes following femoral shaft nonunion without clinical signs of infection treated by a single-stage surgical revision procedure including reamed intramedullary exchange nailing. Methods: A retrospective cohort study was performed in a European level I trauma center between January 2015 and December 2022. Fifty-eight patients were included who underwent reamed intramedullary exchange nailing as a single-step procedure for surgical revision of posttraumatic diaphyseal femoral nonunion without any indications of infection in medical history and without clinical signs of local infection. Clinical details of the patients were analyzed and functional and radiologic long-term outcomes were determined. Results: In all patients, with and without proof of bacteria osseous, healing could be observed. The physical component summary of the SF-12 demonstrated significantly better results at least one year after the final surgical revision in case of a negative bacterial culture during exchange nailing. Conclusions: Clinical long-term outcomes demonstrated a trend towards better results following femoral shaft nonunion revision if there was no evidence for the presence of low-grade infected nonunion. In this case, a single-stage surgical procedure may be recommended.

A fatal case of neonatal viral sepsis caused by human parainfluenza virus type 3

BackgroundSepsis is a systemic inflammatory response syndrome caused by severe infection in children, but cases of sepsis associated with human parainfluenza virus (HPIV) have been rarely reported in newborns.Case presentationWe report a case of HPIV-3 positive full-term newborn admitted to the Neonatal Intensive Care Unit of Beijing Children’s Hospital due to hematuria, gloomy spirit, inactivity and loss of appetite for 6 h. He had septic shock when he arrived the Accident & Emergency Department requiring immediate intubation and mechanical ventilation. Intravenous antibiotics were started. He had completely negative response to all anti-shock treatments including fluid resuscitation and vasopressor supports, and died 14 h later. Viral nucleic acid detection and metagenomic next-generation sequencing (mNGS) analyses of nasopharyngeal aspirate and blood specimens verified an HPIV-3 infection, with negative bacterial culture results. The HPIV-3 strain detected in this patient was subtyped as HPIV C3a, and two unreported amino acid mutations were found in the HN protein region.ConclusionThe patient had a severe infection associated with HPIV-3, which was the cause of sepsis and septic shock. This study showed the diagnostic value of mNGS in etiological diagnosis, especially in severe neonatal case.

Association Between Biofilm Formation by U.P.E.C. and Serum Level of Several Cytokines

One hundred and eighty-nine subjects from Baghdad enrolled in this study (110 female and 79 male) and gathered into two investigated groups; the first group consisted of 149 patients, and the second group consisted of 40 healthy individuals. Results revealed after clinical laboratory diagnosis of urine samples 12 (8.1%) gave a negative bacterial culture, 137 (91.9%) were positive culture, while all urine samples of healthy control were negative. Gram staining and microscopic examination of bacterial colonies showed that 11(8.03%) out of 137 isolates were identified as Gram-positive and 126 (91.97%) as Gram-negative. After biochemical analysis and diagnosis by the Vitik system, the data demonstrated that a single infectious agent caused all U.T.I. cases. U.P.E.C. represented the most common bacterial agent because of several virulence factors responsible for its pathogenicity. The test tube method and Congo red agar medium have been used to detect biofilm formation. Results demonstrate that 129 (94.16 %) of bacterial isolates were producers, while just 8 (5.84 %) were non-producers. The results of the microtiter plate method revealed that the isolates were categorized into four groups: Strong, moderate, weak, and harmful. 22 (63.5%) were strong biofilm producers, 28 (20.449%) were moderate producers, 14 (10.22%) were weak producers, and 8 (5.84%) were unable to form biofilm. Serum levels of IL-1β, IL-6 and IL-8 were estimated by Sandwich ELISA, which were significantly higher in patients with different types of U.T.I.s than the healthy group. This study concluded that the U.P.E.C. represented the most common prevalent agent of U.T.I.s and more efficient biofilm-producer bacteria. The test tube method is the best qualitative, quick, and easy detection method of biofilm formation, while the microtiter plate is the best quantitative and sensitive method. A positive correlation was found between biofilm formation and elevated serum levels of proinflammatory cytokines, proportionally increased with advanced and severe, especially in old persons. Keywords: UTIs; ELISA; IL-1β; IL-6; IL-8; Iraq

Therapeutic efficacy of vancomycin-loaded carbon fiber-reinforced polyetheretherketone hip stem for periprosthetic joint infection: A pilot study.

A carbon fiber-reinforced polyetheretherketone (CFR/PEEK) hip stem with a special antibiotic elution mechanism is under development to treat periprosthetic joint infection (PJI). The antibiotic elution characteristics of intramedullary implants were experimentally investigated, and the efficacy of revision surgery using a therapeutic stem in treating ovine PJI was examined. To evaluate elution characteristics, the intramedullary vancomycin-loaded CFR/PEEK cylindrical implants were inserted in the distal femur of nine sheep, and the vancomycin elution rate was measured at 2, 7, and 21 days. To evaluate therapeutic efficacy, the PJI model with staphylococcus aureus was attempted to create for five sheep. Moreover, the therapeutic vancomycin-loaded CFR/PEEK stem was implanted during one-stage revision surgery. Three weeks after revision surgery, the treatment efficacy was evaluated based on bacterial cultures and wound findings. In addition, the vancomycin elution rate from the stem was measured. On average, the cylindrical implants eluted approximately 70% vancomycin in 21 days. Of the five sheep attempting to create a PJI model, three were successfully infected with S. aureus as intended for verification of treatment efficacy. In all three joints, negative bacterial cultures and no purulence were observed 3 weeks after revision surgery. The vancomycin elution rates from the stems were >70%. Efficient elution of vancomycin was confirmed by the experimental implant inserted into the bone marrow and the stem in actual PJI treatment. Using a novel therapeutic stem with an antibiotic elution mechanism in one-stage revision surgery, successful treatment was demonstrated in all S. aureus-induced PJIs.

Clinical manifestation and treatment strategy of intervertebral space infection after radiofrequency ablation of lumbar nucleus pulposus

To study the clinical manifestations and treatment of intervertebral space infection after percutaneous lumbar radiofrequency ablation of nucleus pulposus. A retrospective analysis was performed of 496 patients who underwent percutaneous lumbar disc decompression using low-temperature plasma radiofrequency ablation nucleus pulposus from June 2009 to June 2019. Six patients had lumbar infection, and the infection rate was 1.21%. All patients were male, ranging in age from 20 to 61 years old. Three patients underwent single segment radiofrequency ablation, two patients underwent dual segments ablation;and one patient underwent three segment ablation, totaling 10 intervertebral discs. One patient was complicated with type 2 diabetes before operation. The interval between infection occurrence ranged from 21 to 65 days. All 6 patients were followed up, and the duration ranged from 18 to 40 months, with an average of 24 months. Among them, 2 patients presented with symptoms of low back pain accompanied by fever, and imaging examination showed intervertebral space infection accompanied by abscess. In addition, 4 patients experienced low back pain but no fever, and MRI showed abnormal signals of the infected intervertebral endplate or vertebral body. One patient showed staphylococcus aureus in blood culture, while the remaining 5 patients showed negative bacterial culture. All the patients were treated with antibiotics after diagnosis. Four patients were treated with conservative management to control infection;1 patient was treated with debridement of posterior lumbar infection focus, and 1 patient was treated with debridement of posterior lumbar infection focus combined with interbody fusion and internal fixation. The occurrence of intervertebral space infection during lumbar radiofrequency ablation nucleoplasty should be given sufficient attention. Strict aseptic technique, avoiding repeated multi segment puncture, realizing early detection and treatment, and selecting appropriate treatment methods according to the severity of infection is the guarantee of achieving curative effect.

Clinical utility of prior positive cultures to optimize empiric antibiotic therapy selection: A cross-sectional analysis

BackgroundDespite reduced infectious disease mortality and improved survival, infectious diseases continue to pose health threats due to their contagiousness, societal harm, and morbidity. Empiric antibiotic therapy, often prescribed without knowledge of the causative pathogen, faces challenges from rising antibiotic resistance. This study explores the potential of prior positive culture results to guide empiric antibiotic therapy. MethodsData from King Abdullah University Hospital (Jan 2014–Dec 2019) included adult patients with recurrent bacterial infections (pneumonia, sepsis, UTIs, wounds). Excluded cases included: mixed infections, transfers, <14 days or >12 months between episodes. The study compared bacterial growth and sensitivity patterns between previous and recent cultures. ResultsThe study included 970 episodes from 650 patients, mainly UTIs (60.3%) and gram-negative bacteria (77.9%). The study found that (65.1%) of culture pairs matched. Empirical therapy was accurate in (71.8%) of cases. Further, accuracy of selected empiric antibiotic therapy was significantly predicted (p ​< ​0.001) by: type of infection, type of antibiotics, and concordance with prior microbiologic data. Multivariate logistic analysis showed blood culture as less predictive of pending identity (OR: 0.234, P ​< ​0.001) compared to urine culture; and prior affirmed gram negative bacterial culture was less predictive (OR: 0.606, P ​= ​0.021) compared to gram positive bacterial culture. ConclusionThis study underscores the potential of prior positive culture results in guiding empiric antibiotic therapy, enhancing accuracy and identity agreement. Future research should explore this approach in different infection contexts and across multiple centers. Reducing the indiscriminate use of broad-spectrum antibiotics is essential to combat antibiotic resistance.

Reducing antimicrobial overuse through targeted therapy for patients with community-acquired pneumonia: a study protocol for a cluster-randomized factorial controlled trial (CARE-CAP)

BackgroundCommunity-acquired pneumonia (CAP) is a significant public health concern and a leading cause of hospitalization and inpatient antimicrobial use in the USA. However, determining the etiologic pathogen is challenging because traditional culture methods are slow and insensitive, leading to prolonged empiric therapy with extended-spectrum antibiotics (ESA) that contributes to increased hospital length of stay, and antimicrobial resistance. Two potential ways to reduce the exposure to ESA are (a) rapid diagnostic assays that can provide accurate results within hours, obviating the need for empiric therapy, and (b) de-escalation following negative bacterial cultures in clinically stable patients.MethodsWe will conduct a large pragmatic 2 × 2 factorial cluster-randomized controlled trial across 12 hospitals in the Cleveland Clinic Health System that will test these two approaches to reducing the use of ESA in adult patients (age ≥ 18 years) with CAP. We will enroll over 12,000 patients and evaluate the independent and combined effects of routine use of rapid diagnostic testing at admission and pharmacist-led de-escalation after 48 h for clinically stable patients with negative cultures vs usual care. We hypothesize that both approaches will reduce days on ESA. Our primary outcome is the duration of exposure to ESA therapy, a key driver of antimicrobial resistance. Secondary outcomes include detection of respiratory viruses, treatment with anti-viral medications, positive pneumococcal urinary antigen test, de-escalation by 72 h from admission, re-escalation to ESA after de-escalation, total duration of any antibiotic, 14-day in-hospital mortality, intensive care unit transfer after admission, healthcare-associated C. difficile infection, acute kidney injury, total inpatient cost, and hospital length-of-stay.DiscussionOur study aims to determine whether identifying an etiological agent early and pharmacist-led de-escalation (calling attention to negative cultures) can safely reduce the use of ESA in patients with CAP. If successful, our findings should lead to better antimicrobial stewardship, as well as improved patient outcomes and reduced healthcare costs. Our findings may also inform clinical guidelines on the optimal management of CAP.Trial registrationClinicalTrials.gov NCT05568654. Registered on October 4, 2022.

Use of polymyxin B with different administration methods in the critically ill patients with ventilation associated pneumonia: a single-center experience.

Background: Whether nebulized polymyxin B should be used as an adjunctive therapy or substitution strategy to intravenous polymyxin B for the treatment of ventilator-associated pneumonia (VAP) remains controversial. This study's aim is to evaluate the efficacy and safety of different administration ways of polymyxin B in the treatment of ventilator-associated pneumonia caused by extensively drug-resistant Gram-negative bacteria(XDR-GNB). Methods: This retrospective cohort study enrolled ventilator-associated pneumonia patients caused by XDR-GNB treated with polymyxin B in the intensive care unit. Patients were categorized by the administration methods as intravenous (IV) group, inhaled (IH) group, and the intravenous combined with inhaled (IV + IH) group. Microbiological outcome and clinical outcome were compared in each group. The side effects were also explored. Results: A total of 111 patients were enrolled and there was no difference in demographic and clinical characteristics among the three groups. In terms of efficacy, clinical cure or improvement was achieved in 21 patients (55.3%) in the intravenous group, 19 patients (50%) in the IH group, and 20 patients (57.1%) in IV + IH group (p = 0.815). All three groups showed high success rates in microbiological eradication, as 29 patients with negative cultures after medication in inhaled group. Among all the patients who had negative bacterial cultures after polymyxin B, the inhaled group had significantly shorter clearance time than the intravenous group (p = 0.002), but with no significant difference in 28-day mortality. Compared with intravenous group, a trend towards a lower risk of acute kidney injury was observed in inhaled group (p = 0.025). Conclusion: From the perspective of minimal systemic renal toxicity, nebulized polymyxin B as a substitution strategy to intravenous polymyxin B for the treatment of ventilator-associated pneumonia caused by XDR-GNB is feasible.

Clinical characteristics of and risk factors for poor outcomes in children with bacterial culture-negative septic arthritis of the hip

BackgroundSeptic arthritis of the hip is a serious infection in children. However, blood and joint fluid cultures are often negative, which makes the diagnosis and treatment challenging. We analyzed the clinical features of children with septic arthritis of the hip with negative bacterial cultures and identified the risk factors for poor outcomes. MethodsThe clinical data of children with septic arthritis of the hip with negative bacterial cultures who were treated at our hospital from January 2010 to December 2020 were retrospectively analyzed. The clinical characteristics and outcomes of the culture-negative cohort were compared with those of children with positive bacterial cultures treated during the same period. Culture-negative patients were divided into a group with good outcomes and a group with poor outcomes. The differences between the two groups were compared. ResultsThirty-nine children with culture-negative septic arthritis of the hip were compared with 37 children with culture-positive sepsis. Compared with the culture-positive group, the culture-negative group had a significantly younger mean age and a significantly lower mean serum C-reactive protein concentration. Logistic regression analysis of culture-negative patients with good versus poor outcomes revealed that the independent risk factors for poor outcomes were an increased serum C-reactive protein concentration and prolonged time from onset to surgery. The cut-off values for predicting a poor outcome in the culture-negative group were a time from onset to surgery of greater than 21 days and a C-reactive protein concentration of greater than 23 mg/L. ConclusionsCulture-negative septic arthritis of the hip has similar clinical features to culture-positive septic arthritis of the hip and can result in sequelae of varying severity. Therefore, active anti-infective and hip drainage therapy should be performed when children present with clinical symptoms, inflammatory marker concentrations, and imaging findings that are clinically diagnostic for septic arthritis of the hip. Level of evidenceLevel II, retrospective study.

Repeated sessions of PACK-CXL WA for the treatment of resistant bacterial keratitis: a retrospective study

ObjectiveThe aim of this work is to evaluate the safety and efficacy of repeated sessions of photo-activated chromophore for keratitis-cross linking (PACK-CXL) window absorption (WA) for the treatment of resistant bacterial keratitis (BK).Patients and methodsThis is a retrospective clinical cohort study. Thirty eyes with clinically suspected and lab-confirmed bacterial keratitis, resistant to appropriate antibiotic therapy- which was modified by sensitivity reports- for 2 weeks with failure of epithelialization for 4 weeks after the standard anti-microbial therapy (SAT) together with one setting of PACK-CXL WA were included. If after the first session of PACK-CXL, there is a start of improvement in the form of reduction of the size of corneal ulcer and stromal infiltrates together with the start of epithelialization on clinical examination and AS-OCT, another session of PACK-CXL WA was performed after one week, and so on, till the complete healing and resolution of bacterial keratitis and confirmation by negative bacterial culture. Identification of the micro-organisms was done by lab study before and after treatment. Corneal healing was evaluated by corneal examination and anterior segment OCT (AS-OCT).ResultsThirty eyes of 30 patients were recruited in this study. They were 16 males and 14 females, their mean age was 44.3 ± 5.38 years. The mean ulcer size was 3.96 ± 1.87 (mm3), while the mean size of stromal infiltrates was 4.52 ± 2.24 (mm3). PACK-CXL WA treatment was performed an average of 2.87 times for the 30 eyes. Complete healing and resolution (Successful treatment) was observed in 27 eyes (90%) of cases and failure of epithelialization was observed only in 3 eyes (10%). Complete corneal healing was reported in the second month postoperatively in 90% of eyes.Conclusion and recommendationPACK-CXL WA may be a promising, non-invasive treatment option for resistant bacterial keratitis. It may have a synergistic effect with standard antimicrobial treatment (SAT). Also, it can overcome the antibiotics resistance that has become rapidly spreading worldwide. Repeated sessions of PACK-CXL WA may be more effective for the treatment of resistant bacterial keratitis till complete epithelialization and resolution of BK than a single session with few complications. However, further prospective and comparative studies to support the results are needed.

RNA in situ hybridization of Escherichia coli in equine endometrial biopsies.

Endometritis is one of the major causes of infertility in mares. Escherichia coli and β-haemolytic streptococci are among the bacterial species most frequently isolated from the equine uterus. Some bacteria such as β-hemolytic streptococci, can persist in dormant forms and cause prolonged, latent or recurrent infections. Dormant bacteria may be present despite negative bacterial cultures, and they are resistant to antimicrobial treatment due to their resting metabolic state. The purpose of this study was to study formalin-fixed paraffin-embedded equine endometrial biopsies for the presence and localization of E. coli-bacteria, with a chromogenic RNAscope®-method for detection of E. coli-related 16S ribosomal RNA. Hematoxylin-eosin-stained endometrial biopsies were evaluated to determine the level of inflammation and degeneration. During estrus, samples were taken for endometrial culture and cytology with a double-guarded uterine swab. The samples included eight samples with moderate to severe endometrial inflammation detected in endometrial histopathology, and growth of E. coli in bacterial culture, six samples with moderate to severe endometrial inflammation but negative bacterial culture, and five samples with no endometrial pathology (grade I endometrial biopsy, negative endometrial culture and cytology) serving as controls. Positive and negative control probes were included in the RNA in situ hybridization, and results were confirmed with a fluorescence detection method (fluorescence in situ hybridization). Only unspecific signals of limited size and frequency of occurrence were detected in all samples, with random localization in the endometrium. No samples contained rod-shaped signals corresponding to bacterial findings. In conclusion, there was no evidence of bacterial invasion in the endometrium regardless of the inflammatory status of the biopsy or previous bacterial culture results. According to these findings on a small number of samples, invasion of E. coli is not a common finding in the lamina propria of mares, but these bacteria may also evade detection due to localized foci of infections, or supra-epithelial localization under the cover of biofilm. These bacteria and biofilm covering the epithelium may also be lost during formalin-fixation and processing.