Concomitant Blood Cultures Research Articles

The Utility of IR-Guided Biopsy in the Treatment of Pediatric Osteomyelitis

Accurate and efficient diagnosis, as well as a consistent and effective treatment of acute hematogenous osteomyelitis, are paramount to ensure successful clinical outcomes. Noninvasive measures of isolating the causative pathogen from blood cultures have low sensitivity, with published rates often <50%. The use of interventional radiology (IR)-guided percutaneous biopsy has gained traction as a nonsurgical means of obtaining tissue cultures with a reported increased sensitivity of >90%. This study aims to determine the utility of IR-guided biopsy in the management of pediatric patients with acute hematogenous pediatric osteomyelitis (OM). An IRB-approved retrospective review was completed of children younger than 18 years admitted to a single institution for treatment of magnetic resonance imaging or culture/biopsy-proven acute hematogenous OM. Patients were excluded for the diagnosis of chronic recurrent multifocal OM, incomplete documentation, treatment initiation at an outside institution, open surgical debridement, and concomitant septic arthritis. Patients who underwent IR-guided biopsy were compared with those treated empirically without biopsy. Fifty patients were included for analysis. Fifteen (30%) had IR-guided biopsies; 35 (70%) were treated empirically. The average age at diagnosis was 11.8 years old (SD: 4.9). Of the 15 patients who underwent IR-guided biopsy, a pathogen was identified in 12 cases (80%); 14 of these patients had concomitant blood cultures with only 1 (7%) positive result ( P <0.01). Of the 11 patients with positive IR-guided biopsy results in the setting of negative blood cultures, 9 (82%) had alterations in their antibiotic regimen as a result of the biopsy. The average time from blood sample collection to definitive antibiotic initiation was nearly double that of time from IR-guided biopsy collection to definitive antibiotic initiation (70.8 vs. 36h; P <0.01). IR-guided biopsy increased pathogen identification by 47% over blood cultures alone and decreased the time to definitive antibiotics. As such, IR-guided biopsy is an effective and safe diagnostic tool for pathogen identification and appropriate antibiotic selection. Orthopaedic surgeons are encouraged to incorporate IR-guided biopsy early in the treatment pathway for patients with acute OM without an indication for open surgical intervention. Level III; retrospective comparative study.

T2Bacteria and T2Resistance Assays in Critically Ill Patients with Sepsis or Septic Shock: A Descriptive Experience.

The use of rapid molecular tests may anticipate the identification of causative agents and resistance determinants in the blood of critically ill patients with sepsis. From April to December 2021, all intensive care unit patients with sepsis or septic shock who were tested with the T2Bacteria and T2Resistance assays were included in a retrospective, single center study. The primary descriptive endpoints were results of rapid molecular tests and concomitant blood cultures. Overall, 38 combinations of T2Bacteria and T2Resistance tests were performed. One or more causative agent(s) were identified by the T2Bacteria assay in 26% of episodes (10/38), whereas negative and invalid results were obtained in 66% (25/38) and 8% (3/38) of episodes, respectively. The same pathogen detected by the T2Bacteria test grew from blood cultures in 30% of cases (3/10). One or more determinant(s) of resistance were identified by the T2Resistance assay in 11% of episodes (4/38). Changes in therapy based on T2Bacteria and/or T2Resistance results occurred in 21% of episodes (8/38). In conclusion, T2Bacteria/T2Resistance results can influence early treatment decisions in critically ill patients with sepsis or septic shock in real-life practice. Large, controlled studies remain necessary to confirm a favorable impact on patients' outcomes and antimicrobial stewardship interventions.

Urinary tract infection is common in VLBW infants

Determine the significance of urinary tract infection (UTI) as a cause of late onset sepsis (LOS) in very low birth weight (VLBW) infants in the Neonatal Intensive Care Unit (NICU). Analysis of blood, cerebrospinal fluid and urine culture results in VLBW infants >72-h old, admitted to the Georgetown University Hospital NICU between 2005 and 2015. Of 527 VLBW infants, 297 (56.4%) underwent 911 evaluations for LOS; only one-third included urine cultures. UTI was diagnosed in 8.5% of VLBW infants (range 2-15.9%) and in 13.8% of infants weighing < 1000 g at birth. Gram-negative infections predominated. Concomitant blood cultures were negative in 96% of infants. UTI was more common than bloodstream infection by 2015. UTI is a significant cause of infection in VLBW infants. Urine culture should be included in all LOS evaluations in order to facilitate accurate diagnosis and appropriate antibiotic therapy.

Surveillance of catheter-related infections: the supplementary role of the microbiology laboratory.

BackgroundThe burden of catheter-related infections (CRIs) in developing countries is severe. In South Africa, a standardised surveillance definition does not exist and the collection of catheter days is challenging. The aim of the study was to provide baseline data on the prevalence of CRIs and to describe the epidemiology of CRI events within a tertiary academic hospital.MethodsSurveillance was laboratory-based and conducted for a six month period. A microbiologically confirmed CRBSI (MC-CRBSI) event was defined as the isolation of the same microorganism from the catheter and concomitant blood cultures (BCs), within 48 h of catheter removal, which were not related to an infection at another site.ResultsA total of 508 catheters, removed from 332 patients, were processed by the laboratory, of which only 50% (253/508 removed from 143/332 patients) of the catheters were accompanied by BCs within 48 h. Sixty-five episodes of MC-CRBSI in 57 patients were detected, involving 71 catheters and 195 microbial isolates. The institutional prevalence rate was 3.7 episodes per 1 000 admissions and 5.8 episodes per 10 000 in-patient days. Catheter day data was collected in only six wards of the hospital. The pooled laboratory incidence was 10.1 MC-CRBSI episodes per 1 000 catheter days, whereas the hospital-based central line-associated bloodstream infection (CLABSI) rate was pooled at 5.7 episodes per 1 000 catheter days. The majority of patients had an underlying gastro-intestinal condition (33%; 19/56) with a non-tunnelled, triple-lumen central venous catheter, placed in the subclavian vein (38%; 27/71). The most predominant pathogen was methicillin-resistant Staphylococcus epidermidis (28%; 55/195), followed by extensively-drug resistant Acinetobacter baumannii (18%; 35/195).ConclusionsCatheter-related infection prevention and control efforts require urgent attention, not only to keep patients safe from preventable harm, but to prevent the spread of multidrug resistant microorganisms.

Importance of blood cultures from peripheral veins in pediatric patients with cancer and a central venous line.

When an infection is suspected in a child with cancer and a central venous line (CVL), cultures are often only obtained from the CVL and not from a peripheral vein (PV). This study was undertaken to evaluate the importance of concomitant blood cultures from the CVL and a PV. Clinical data and the results of all cultures taken concomitantly from the CVL and a PV were registered prospectively in children admitted with fever from April 2008 to December 2012 at the Department of Pediatrics at Aarhus University Hospital Skejby. During the study period 654 paired cultures obtained from the CVL and from a PV within two hour of each other were included. A true bloodstream infection (BSI) was registered in 112 episodes. In 20 (17%) out of 112, true BSI growth of a microorganism was detected only in the culture from a PV including seven cases of Escherichia coli and three cases of Staphylococcus aureus. In 52 episodes the same microorganism was cultured from both the CVL and a PV. Twenty-four of these episodes were classified as catheter-related bloodstream infections (CRBSI) using differential time to positivity. In total, 64 (57%) of all true BSI were defined as CRBSI. Blood cultures should be obtained from a PV in addition to cultures from CVL at the onset of fever in pediatric patients with cancer in order to maximize the findings of true BSIs. The frequency of CRBSI may be over-estimated if blood cultures are drawn from CVL only.

Microbiologic analysis of peri-pancreatic fluid collected during EUS in patients with pancreatitis: impact on antibiotic therapy

Pancreatitis is a potentially life-threatening condition frequently accompanied by peri-pancreatic fluid collections (PPFC), such as pseudocysts or pancreatic necrosis. Aspiration of PPFCs during EUS interventions for microbiologic analysis is still rarely performed in clinical routine. To evaluate the role of routine microbiologic analysis of PPFCs and its impact on antibiotic therapy in patients with pancreatitis. Prospective, observational, multicenter study. Four treatment centers. A total of 44 consecutive patients who presented for endoscopic treatment of PPFCs were included. Concomitantly, PPFC during intervention and concomitant blood cultures were obtained. Microbiologic examination of PPFCs and blood samples. Colonization of PPFCs was found in 59% of PPFC cultures, whereas all but 2 concomitant blood cultures showed no microbial growth. Risk factors for a colonization were the presence of necrosis (P= .006), acute pancreatitis (P= .033), leukocytosis (P= .001), elevated C-reactive protein levels (P= .003), fever (P= .02), turbid material (P= .031), and longer hospital stay (P= .003). In 23 patients with fluid colonization despite empiric antibiotic therapy, the treatment had to be adjusted in 18 patients (78%) according to the observed antibiotic susceptibility profile. Contamination cannot be totally excluded. The microbiologic colonization of PPFCs in patients with pancreatitis is common. Only the direct microbiologic analysis of PPFCs, but not of blood cultures, is useful to optimize an effective antibiotic therapy in patients with pancreatitis.

Evaluation of a Polymerase Chain Reaction Assay for Pathogen Detection in Septic Patients under Routine Condition: An Observational Study

BackgroundTreatment of septic shock relies on appropriate antimicrobial therapy. Current culture based methods deliver final results after days, which may delay potentially lifesaving adjustments in antimicrobial therapy. This study was undertaken to compare PCR with blood culture results under routine conditions regarding 1. impact on antimicrobial therapy, and 2. time to result, in patients with presumed sepsis.Methodology/Principal FindingsThis was an observational study in a 50 beds ICU of a university hospital. In 245 patients with suspected sepsis, 311 concomitant blood cultures and blood for multiplex PCR (VYOO®) were obtained. 45 of 311 blood cultures (14.5%) and 94 of 311 PCRs (30.1%) were positive. However, blood culture or microbiological sampling from the presumed site of infection rarely confirmed PCR results and vice versa. Median time to positivity and interquartile range were 24.2 (18.0, 27.5) hours for the PCR and 68 (52.2, 88.5) hours for BC (p<0.01). PCR median time to result was dependent on technician availability (53.5 hours on Saturdays, 7.2 hours under optimal logistic conditions). PCR results showed good correlation with procalcitonin (p<0.001). In 34% of patients with positive PCRs antimicrobial therapy was considered inadequate according to assessment of clinical arbitrators including 5 patients with vancomycin-resistant enterococci (VRE), 3 cases with multiresistant staphylococci, and 4 patients with fungi.ConclusionsThe results of this observational study support the hypothesis that PCR results are available faster, are more frequently positive, and may result in earlier adjustment of antimicrobial therapy. However, shorter time to result can only be fully exploited when the laboratory is adequately staffed for a 24 hour/7 day service, or when point of care/automated assay systems become available.

Clinical significance of Candida colonization of intravascular catheters in the absence of documented candidemia

In order to assess the significance of Candida colonization of intravascular catheters (IVC) in patients without documented candidemia, we retrospectively reviewed all Candida-positive IVC tip cultures over a 4-year period. Cases were defined as those with a culture yielding ≥15 colony-forming units of Candida spp. that either did not have blood cultures (BC) taken or had concomitant BC negative for Candida. Patients were followed up until death or 8 months after discharge. Risk factors for poor outcome following IVC removal (death, candidemia, or Candida-related complication) were analyzed. We analyzed a total of 40 patients. Overall mortality was 40.0%, with no death directly attributed to Candida infection. Twenty-two patients received antifungal therapy at the time of IVC removal. Only 1 patient developed a metastatic complication (chorioretinitis) attributable to transient candidemia (2.5% of the global cohort and 3.7% among those with concomitant BC). There were no cases of subsequent candidemia. In the multivariate analysis, the use of antifungal therapy did not show any impact on the risk of poor outcome. The risk of invasive disease in patients with isolated IVC colonization by Candida seems to be low. Nevertheless, the initiation of systemic antifungal therapy should be carefully considered in such context.

Development of bacteraemia or fungaemia after removal of colonized central venous catheters in patients with negative concomitant blood cultures

There are limited data on the clinical significance of -positive central venous catheter (CVC) tip cultures associated with concomitant negative blood cultures performed at the time of CVC removal. A retrospective cohort study of all patients who yielded isolated -positive CVC tip cultures was conducted in a tertiary-care hospital with 2200 beds during a 10-year period. All patients with isolated -positive CVC tip cultures were observed for the development of subsequent bacteraemia or fungaemia between 2 and 28 days after CVC removal. An isolated -positive CVC tip culture was defined as a case in which (i) a CVC tip culture yielded ≥15 colonies using a semiquantitative culture method and (ii) at least two sets of blood samples revealed no organism at, or close to, the time of CVC removal (48 h before to 48 h after CVC removal). During the study period, 312 patients with isolated -positive CVC cultures were enrolled. Eight (2.6%; 95% CI 1.2–5.1) of the 312 patients yielding isolated bacterial or fungal CVC tip cultures developed subsequent bloodstream infection (BSI) caused by the same species as that isolated from the tip culture (Staphylococcus aureus, 1: Enterococcus spp.; 2: Pseudomonas aeruginosa; and 3: Candida spp.). Among 125 patients from whose CVC tips the above four organisms were grown, seven (12.3%) of 57 patients who did not receive appropriate antibiotic therapy within 48 h after CVC removal subsequently developed BSI, but only one (1.5%) of 68 patients who did receive appropriate therapy developed BSI (OR 0.11, p 0.02).

Infectious Granulomatous Dermatitis Associated With Rothia mucilaginosa Bacteremia: A Case Report

Infections with rare pathogens are being recognized with increasing frequency in severely immunocompromised patients. As a result of these patients' underlying compromised defenses and susceptibility to atypical organisms, tissue biopsies from patients within this population may demonstrate nonclassical histopathological findings. Here, we describe an unusual granulomatous reaction to gram-positive cocci in the skin of a 52-year-old man undergoing salvage chemotherapy for acute myeloid leukemia. The patient presented with a papular eruption on the arms, trunk, and face and fever; concomitant blood cultures were positive for Rothia mucilaginosa and Streptococcus salivarius. Histologic evaluation revealed a granulomatous dermatitis associated with numerous small, round, predominantly intracellular bacteria. Classically, cutaneous infiltrates associated with coccoid bacterial infections are suppurative and not granulomatous. The intracellular organisms stained positive for Gram, periodic acid-Schiff, and Grocott methenamine silver stains, suggestive of R. mucilaginosa. Rothia mucilaginosa, a component of the oral flora, was first reported as a human pathogen in 1978. Although the majority of cases in the literature have described R. mucilaginosa bacteremia, other reported manifestations include meningitis, endocarditis, pneumonia, osteomyelitis, and peritonitis. To our knowledge, however, only 1 prior report has described a cutaneous manifestation of R. mucilaginosa septicemia, which occurred in a patient with neutropenia. This is the second reported case of an infectious granulomatous dermatitis associated with R. mucilaginosa bacteremia and raises awareness of this unusual histopathological presentation in the setting of a bacterial infection affecting the skin.

The Efficacy of Palliative and Definitive Percutaneous Versus Surgical Drainage of Pancreatic Abscesses and Pseudocysts

We compared the efficacy of percutaneous to surgical drainage in a prospective study in 85 patients with pancreatic abscesses and pseudocysts. Percutaneous drainage of pancreatic abscesses in 18 patients cured three and palliated 12 who were eventually cured by elective surgical ablation; three patients died. This compares well to our 15 surgical patients, of whom four were cured by surgery alone and six were palliated. All were subsequently cured by additional computerized tomography-guided or ultrasound-guided percutaneous drainage and medical management or surgery. Five of the 15 died. Percutaneous drainage cured 11 of 14 infected pseudocysts and palliated two, which were subsequently cured by surgery; one was palliated but the patient was lost to follow-up. Surgical drainage cured six of 12 infected pseudocysts and palliated the other six, of which four were cured by further surgery and the other two were cured by secondary percutaneous drainage. Nine of 12 noninfected pseudocysts were cured by percutaneous aspiration, and two were palliated and later cured. In one patient, disease progressed, and he was ultimately lost to follow-up. Thirteen of 14 noninfected pseudocysts were cured by surgical drainage. The other patient died of pulmonary embolus. In patients treated by percutaneous techniques, there were four major complications. Our study established distinct advantages of percutaneous drainage under computerized tomographic and ultrasonic guidance: (1) the procedures can be carried out under ultrasonic guidance in an intensive care unit on critically ill patients, (2) the technique proved highly effective for initial palliation, with defervescence and stabilization occurring in most critically ill patients within 48 hours, (3) findings from fine needle aspiration provided valuable information as to microorganisms and antibiotic sensitivities and differed in 29 of 85 patients from those of concomitant blood cultures, and (4) definitive eradication of the process (surgical ablation of residual necrotic material) can be elected after the patient's clinical condition stabilizes.