Routine Blood Cultures Research Articles

Assessment of anaerobic blood cultures in pediatric oncology patients

IntroductionThe routine use of a single aerobic bottle for blood culture in pediatric patients has become commonplace, as anaerobic bacteria are not frequently involved in clinically significant infections. The aim of this study was to assess the usefulness of routinely performing anaerobic blood cultures in pediatric oncology patients. MethodsProspective study was conducted on pediatric (<18 years) patients affected with febrile syndrome after receiving chemotherapy for hematological or solid malignancies. Samples were inoculated into pediatric aerobic and standard anaerobic bottles (BacT/Alert automatic system). Strains were considered clinically significant, or deemed as contaminants, depending on isolation circumstances and clinical criteria. ResultsA total of 876 blood cultures from 228 patients were processed during the 21-month study period (January 2014 to September 2015). Baseline diagnosis included 143 solid tumors and 67/18 cases of leukemia/lymphoma. Bacterial growth was detected in 90 (10.2%) blood cultures for 95 different isolates, of which 62 (7.1%)/63 isolates were considered clinically significant. Among the latter, 38 (60.3%) microorganisms grew in both aerobic and anaerobic bottles, 18 (28.6%) only in aerobic bottles, and 7 (11.1%) only in anaerobic bottles. Gram-negative bacilli (33; 52.4%), mainly from the Enterobacteriaceae family, were the most frequently isolated microorganisms. Overall, only 3 out of 90 isolates (3.3%) were strict anaerobes (Propionibacterium acnes), and all of them were deemed contaminants. ConclusionStrict anaerobes did not cause significant infections in febrile pediatric oncology patients, and anaerobic blood culture bottles offered no additional advantages over aerobic media. Our results suggest that routine blood cultures should be solely processed in aerobic media in this group of patients.

Viral Infections in Neonates with Suspected Late-Onset Bacterial Sepsis-A Prospective Cohort Study.

Objective The aim of our study was to evaluate the occurrence of viral infections in infants with suspected late-onset bacterial sepsis in a neonatal intensive care unit. Methods In a prospective study, infants with suspected late-onset bacterial sepsis underwent viral testing alongside routine blood culture sampling. Using a multiplex reverse transcription-polymerase chain reaction enzyme-linked immunosorbent assay, nasopharyngeal aspirates were analyzed for adenovirus, respiratory syncytial virus (RSV), influenza virus A and B, H1N1 virus, parainfluenza virus 1 to 4, metapneumovirus, coronavirus, and picornavirus. Stools were examined for adenovirus, rotavirus, norovirus, and enterovirus. Results Between August 2010 and March 2014, data of 88 infants with 137 episodes of suspected late-onset bacterial sepsis were analyzed. Six infants were diagnosed with a respiratory viral infection (2 × RSV, 4 × picornavirus). Blood culture–proven bacterial sepsis was detected in 15 infants. Neither viral–bacterial coinfections nor polymerase chain reaction positive stool samples were found. Conclusion Respiratory viruses can be detected in a considerable number of neonates with suspected late-onset bacterial sepsis. In contrast, gastrointestinal viral or enterovirus infections appear uncommon in such cases.

Tumor necrosis factor-alpha and interleukin-6 in early-onset neonatal sepsis

Background Neonatal sepsis remains a major cause of mortality and morbidity in newborns. Early-onset neonatal sepsis occurs in infants under the age of 72 hours, while late-onset neonatal sepsis occurs in infants over the age of 72 hours and may be due to nosocomial infection. Diagnosing neonatal sepsis is a challenge, as its clinical symptoms are not clear. Corroborating tests include routine blood, C-reactive protein (CRP), serology, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) examinations.Objective To compare the TNF-α and IL-6 levels in patients with proven and unproven early-onset neonatal sepsis (EONS)Methods This case-control study was done in the Perinatology Unit, Abdul Moeloek Hospital, Lampung. Subjects were under the age of 72 hours with risk factors and clinical symptoms of sepsis. They underwent routine blood tests and blood cultures. Infants with positive cultures were considered to have proven sepsis (26 subjects) and infants with negative blood cultures were considered to have unproven sepsis (26 subjects). All subjects underwent serological examinations of TNF-α and IL-6.Results There were no differences in the basic characteristics of subjects between the two groups. Levels of TNF-α in the sepsis group were significantly higher than in the unproven group [(28.30 vs. 10.96 pg/mL, respectively (P=0.001)]. Furthermore, Il-6 was significantly higher in the proven sepsis group than in the unproven sepsis group [(28.3 vs. 9.69 pg/mL, respectively) (P=0.006)].Conclusion Levels of TNF-alpha and IL-6 are significantly higher in infants with proven than unproven early-onset neonatal sepsis.

Cutaneous manifestations of Helicobacter cinaedi: a review.

Helicobacter cinaedi is an emerging Gram-negative spiral bacillus that was first reported in 1984. It has been implicated as a cause of gastroenteritis and bacteraemia in immunocompromised individuals. Helicobacter cinaedi-associated bacteraemia is sometimes accompanied by skin lesions; however, the cutaneous manifestations of this pathogen are not widely known. To our knowledge, a comprehensive review with detailed analysis of skin lesions associated with H. cinaedi has not been conducted. This article summarizes the clinical appearance of H. cinaedi cellulitis and its management. In addition, we conducted a retrospective review of 73 patients with H. cinaedi bacteraemia at a single institution, to further clarify the characteristic cutaneous features. It was found that 30% (22/73) of the cases of H. cinaedi bacteraemia had sudden-onset erythema accompanied by high fever. The most common cutaneous symptom of H. cinaedi bacteraemia was found to be mild cellulitis, appearing as multiple painful infiltrated erythemas on the extremities. As H. cinaedi is not always detectable in routine blood culture techniques, evaluation of these characteristic cutaneous manifestations seems important in diagnosis. Helicobacter cinaedi infection should be added to the diagnostic list of unspecified fever with painful infiltrated erythemas.

Mycobacterium Avium Complex (MAC) Sepsis in an Immunocompetent Patient Isolated from Routine Blood Culture

Mycobacterium avium complex (MAC) includes Mycobacterium avium and Mycobacterium intracellulare . Disseminated MAC characteristically involves multiple nodes, spleen, liver, bone marrow, and blood, and is an opportunistic infection almost uniquely associated with patients with advanced AIDS with CD4 lymphocyte count 100,000 copies/mL. In HIV negative patients without immunosuppression, …

Judicious utilization of healthcare resources: reducing unindicated pediatric anaerobic blood cultures in a pediatric hospital.

The decline in anaerobic infections in the past 15 years has resulted in healthcare professionals questioning the need for routine anaerobic blood cultures. In this study, we extracted baseline aerobic and anaerobic blood culture rates over the past 10 years (2001-2010) from our pediatric wards. A questionnaire survey of doctors was conducted to gather their views regarding anaerobic blood cultures. Interventions such as physician education were introduced over 6 months to reduce unindicated anaerobic blood cultures. Furthermore, the rates of blood cultures were tracked over time after intervention. Before intervention, 85% of doctors surveyed routinely ordered anaerobic blood cultures, 90% were unaware of any guidelines for anaerobic blood cultures, and 100% were unaware of the costs. The combination of physician education and restrictive interventions resulted in an 80% reduction in the number of anaerobic blood cultures performed and processed, which translated into savings of USD $2,883 per week, with projected savings of USD $145,560 annually.

English

Bacteraemia is a common cause of morbidity and mortality in children worldwide. Therefore, bacteraemia continues to be increasingly a serious health problem that needs an immediate attention and treatment. A retrospective hospital-based study was conducted on positive blood cultures collected from 804 children (aged less than 10 years) including both genders in a period between 2012 and 2013 in three different medical services center in Khartoum state, Sudan, out of 804 tested blood samples, among whom 226 isolates were recovered from blood cultures. The majority of the children with bacteraemia (77.4%) were found to be less than one year old (49.1% male and 50.9% female). The most frequent pathogen was found to be Staphylococcus aureus (33.6%), followed by Klebsiella pneumoniae. (30.5%), Pseudomonas aeruginosa (11.5%), Burkholderia cepacia (10.6%), Streptococcus spp., (7%), Escherichia coli (3.5%), Acinetobacter spp. (1.7%) and coagulase negative staphylococci (1.3%). This study shows the highest susceptibility rate of S. aureus to vancomycin (97.3%), and the lowest susceptibility rate (34.7%) was recorded for erythromycin. Staphylococcus aureus was the main etiological agent of bacteraemia in children, while the most isolates demonstrating susceptibility to vancomycin. Overall, erythromycin resistance was 65.3%. This information should be considered when empirical therapy is recommended for the treatment of children with bacteraemia. Most laboratories in Sudan use a single aerobic blood culture bottle for routine blood culture. So our recommendation is using aerobic in conjugation with anaerobic bottles in order to recover significantly more organisms. Key words: Bacteraemia, children, antimicrobials, drug resistance, Sudan.

Application value of procalcitonin for urosepsis secondary to ureteral calculus

Objective To investigate the value of procalcitonin (PCT) for urosepsis secondary to ureteral calculus. Methods Samples of 68 ureteral calculi patients who were suspected of urosepsis were obtained for PCT level, C-reactive protein (CRP) level, blood routine examination, urinary sediment, blood culture and urine culture. Sixty-eighy patients were divided into urosepsis group and non-urosepsis group based on the urosepsis diagnostic standard. The age sex, stone location, stone size, blood WBC count, CRP level, PCT level and urine WBC count were compared between the 2 groups. PCT levels before and after treatment were also compared. Results The age, stone size in urosepsis group were significantly higher than those in non-urosepsis group. The PCT levels of patients in urosepsis group and non-urosepsis group were 19.09±25.15 μg/L and 2.09±1.85 μg/L respectively before treatment, and there was a significant difference between the 2 groups (P 0.05). The CRP levels of patients in urosepsis group and non-urosepsis group were 17.41±15.24 mg/L and 15.02±4.94 mg/L respectively before treatment (P>0.05). The median urine WBC counts (per HPF) of patients in urosepsis group and non-urosepsis group were 54 and 47 respectively before treatment (P>0.05). The PCT levels of patients in urosepsis group before and after treatment were 19.09±25.15 μg/L and 1.06±0.56 μg/L, and there was a significant difference (P<0.05). Conclusion PCT has a definite value for early diagnosis of urosepsis, condition assessment and treatment guideline. Key words: Procalcitonin; Ureteral calculus; Urosepsis

Direct disk diffusion test using European Clinical Antimicrobial Susceptibility Testing breakpoints provides reliable results compared with the standard method.

Sepsis represents a life-threatening infection requiring the immediate start of antibacterial treatment to reduce morbidity. Thus, laboratories use direct antimicrobial susceptibility testing (AST) to rapidly generate preliminary results from positive blood cultures. As the direct AST has not yet been published to be evaluated with EUCAST breakpoints, the purpose of the study was to investigate the reliability of the direct agar diffusion test to correctly produce AST results from positive monobacterial blood cultures compared with the VITEK2-based definitive AST, when current EUCAST breakpoints were used. A total of 428 isolates from unselected monobacterial routine blood cultures and 110 challenge strains were included. Direct agar diffusion-based and standard VITEK2-based AST of 2803 bacterium-drug combinations yielded a total clinical category agreement of 95.47% with 1.28% very major errors and 3.42% combined major and minor errors. On the species level, very major errors were observed in the species-drug combinations Enterococcus spp.-high-level gentamicin (10.87%) and Staphylococcus spp.-rifampicin (5%), only. No very major errors occurred with Enterobacteriaceae and Pseudomonas aeruginosa. In most species-drug combinations, the direct agar diffusion test using EUCAST breakpoints precisely predicted the result of the definitive antibiotic susceptibility test and, thus, it can be used to optimize empiric antibiotic therapy until definitive results are available.

Routine blood cultures in the management of pyelonephritis in pregnancy for improving outcomes.

Pyelonephritis is a type of urinary tract infection (UTI) that affects the upper urinary tract and kidneys, and is one of the most common conditions for hospitalisation among pregnant women, aside from delivery. Samples of urine and blood are obtained and used for cultures as part of the diagnosis and management of the condition. Acute pyelonephritis requires hospitalisation with intravenous administration of antimicrobial agents. Several studies have questioned the necessity of obtaining blood cultures in addition to urine cultures, citing cost and questioning whether blood testing is superfluous. Pregnant women with bacteraemia require a change in the initial empirical treatment based on the blood culture. However, these cases are not common, and represent approximately 15% to 20% of cases. It is unclear whether blood cultures are essential for the effective management of the condition. To assess the effectiveness of routine blood cultures to improve health outcomes in the management of pyelonephritis in pregnant women. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register without language or date restrictions (31 December 2014). Randomised controlled trials and quasi-randomised trials comparing outcomes among pregnant women with pyelonephritis who received initial management with or without blood cultures. Cluster-randomised trials were eligible for inclusion in this review but none were identified. Clinical trials using a cross-over design were not eligible for inclusion. Two review authors independently assessed one trial report for inclusion. We identified one trial report but this was excluded. No clinical trials met the inclusion criteria for this review. There are no large-scale randomised controlled trials to assess outcomes in the management of pyelonephritis in pregnancy with or without blood cultures. Randomised controlled trials are needed to evaluate the effectiveness of managing pyelonephritis in pregnant women with or without blood cultures, and to assess any adverse outcomes as well as the cost-effectiveness of excluding blood cultures from treatment.

First Case of Tricuspid Valve Endocarditis Caused by Gemella bergeri.

Gemella bergeri is a Gram-positive cocci species arranged in pairs and composes the normal flora of oral cavity, digestive and urinary tract. Several species of Gemella are known to cause endocarditis. Here, we report the first case in Thailand of G. bergeri endocarditis whose blood culture was negative using routine methods but was positive by PCR identification of bacteria in the affected valve. A 37-year-old male presented with prolonged fever, weight loss, and dyspnea on exertion. By transthoracic echocardiography, he was suspected of having infective endocarditis of the tricuspid valve. The patient underwent tricuspid valve repair and vegetectomy. Routine hospital blood cultures were negative but G. bergeri was identified by PCR/sequencing of the heart valve tissue.

Usefulness of routine pairing of anaerobic with aerobic blood culture bottles and decision making on antimicrobial therapy

ObjectivesTo evaluate the growth concordance in paired aerobic/anaerobic sets, and the impact of the anaerobic growth on patients' antimicrobial management.MethodThis is a prospective multicenter study which was conducted in three hospitals, with total beds of 750 beds and 52 ICU beds. Prospectively, laboratory blood cultures logbooks were daily reviewed and patients from whom blood cultures were ordered were followed, their chart were reviewed. Entries on antimicrobial therapeutic changes were noted for all paired sets. Clinicians were blinded to the study, though they were informed about culture results via the usual work protocol in each hospital.ResultsCollected Blood culture sets totaled 2492; 172 single sets were excluded, and 1160 paired sets were analyzed. 1046 were concordant; 79 sets had bacterial growth and 967 sets had no bacterial growth. 114 sets were discordant; 97 in aerobic bottles, 13 in anaerobic, and 4 in both.The proportion of agreement for the concordant paired growth sets was 90.2%. The composite proportion of agreement for sets with any growth (N = 193, composite proportion of agreement = 56%, 95% C.I., 34% - 48%). Cohen kappa composite agreement, measured for the total analyzed paired-sets (N = 1160, K = .52, SE = .038. 95% C.I., .447 - .595). The odds of modifying antimicrobial regimen were for total and subgroups intent to treat odds, based on paired sets showed that one modification took place in one anaerobic growth set (N = 1160, Odds = 0.0008), the odds for all sets with any growth (N = 193, odds = .005), and based on any anaerobic sets (79 concordant, 13 anaerobic, and 4 discordant) with bacterial growth (N = 96: odds = 0.010).ConclusionThe study demonstrates that the proportion of agreement among paired sets were high, and needless to include anaerobic sets in routine blood culture collection. Also the decision-making of anti-infective treatment on patients based on anaerobic blood culture growth was not evident.

Prevalence and characterization of enterotoxigenic Bacteroides fragilis and toxigenic Clostridium difficile in a Taipei emergency department.

Enterotoxigenic Bacteroides fragilis (ETBF) and toxin-encoding Clostridium difficile (TXCD) are associated with gastroenteritis. Routine anaerobic blood culture for recovery of these anaerobic pathogens is not used for the detection of their toxins, especially for toxin-variant TXCD. The aim of this study was to investigate the prevalence and risk factors of the genotypes of these anaerobes in patients with acute diarrheal illnesses. The data and samples of 513 patients with gastroenteritis were collected in a Taipei emergency department from March 1, 2006 to December 31, 2009. Nonenterotoxigenic B. fragilis (NTBF) and ETBF and the toxin genotypes of TXCD were detected by molecular methods. The prevalence rates of NTBF, ETBF, and TXCD infections were 33.14%, 1.56%, and 2.34%, respectively. ETBF infections often occurred in the elderly (average age=67.13 years) and during the cold, dry winters. TXCD infections were widely distributed in age and often occurred in the warm, wet springs and summers. The symptoms of ETBF-infected patients were significantly more severe than those of NTBF-infected patients. This study identified and analyzed the prevalence, risk factors, and clinical presentations of these anaerobic infections. Future epidemiologic and clinical studies are needed to understand the role of ETBF and TXCD in human gastroenteritis.

Clinical impact of reducing routine blood culture incubation time from 7 to 5 days

The aim of this study was to determine the clinical impact of reducing the blood culture incubation protocol from 7 to 5 days.A laboratory data extraction identified positive blood cultures occurring after 5 or more days of incubation at Canberra Hospital, Australia between 1 January 2001 and 31 August 2011. Isolates were identified as clinically significant using a pre-existing prospective bacteraemia database. Medical records review determined whether the positive result affected clinical management.Positive blood cultures after 5 or more days of incubation accounted for 2.65% (423/15979) of all positive blood cultures, although the majority were false positives or contaminants. Eighty-five were significant/indeterminate, representing an average of eight cases per year or 0.47% (85/15979) of all positive blood cultures sets. Forty-three were isolated for the first time, representing 1.1% of all significant/indeterminate blood culture episodes. Fungi and anaerobic bacteria compromised over 50% of isolates. In 26 cases (2.4 cases per year), the culture result led to a change in patient management.A 7 day incubation protocol is preferable due to late isolation of organisms; however, if space is required to accommodate increasing blood culture numbers, reducing to a 5 or 6 day protocol would miss only a small percentage of clinically significant isolates.

Finegoldia magna, not a well-known infectious agent of bacteriemic post-sternotomy mediastinitis

Post-sternotomy mediastinitis, a nosocomial infection mostly caused by staphylococci, can be life-threatening. A case of mediastinitis due to Finegoldia magna after a coronary artery bypass graft surgery was reviewed. Although this bacterium is difficult to be isolated from routine blood cultures, a F. magna bacteriemia associated with mediastinitis was diagnosed.

Utility of routine surveillance blood cultures in asymptomatic allogeneic hematopoietic stem cell transplant recipients with indwelling central venous catheters at a comprehensive cancer center

Many transplant centers obtain surveillance blood cultures (SBCs) from asymptomatic allogeneic hematopoietic stem cell transplant (allo-HCT) recipients with central venous catheters for early detection of potential blood stream infections. The aim of this study was to determine the utility of this practice. We conducted a retrospective study of all patients who underwent allo-HCT to determine the frequency, clinical significance, and costs associated with SBCs. From 776 patients, 6,801 SBCs were obtained (median, 9 per patient). Most (96.89%) were negative. Of the 211 positive SBCs, 171 (81%) had minimal clinical significance. The remaining 40 positive cultures (19%) were considered potentially significant. The frequency of potentially significant SBCs was 5.1% for the entire cohort and 0.59% of all SBCs drawn. All potentially significant cultures and some that were deemed to have minimal significance led to medical intervention, some of which were probably unnecessary. No adverse outcomes occurred in patients with positive SBCs for the first 30 days following the positive result, regardless of the pathogen isolated or the quantitative colony count. The frequency of clinically significant positive SBCs in asymptomatic adult allo-HCT recipients is very low. Routine use of this practice leads to some unnecessary medical interventions and added costs.

Blood Culture Use in the Emergency Department in Patients Hospitalized for Community-Acquired Pneumonia

To the Editor: Routine blood cultures for all patients hospitalized with community-acquired pneumonia have limited utility, and false-positive results lead to inappropriate antimicrobial use and longer hospital stays.1 As a result, performance measures and practice guidelines that promoted obtaining blood cultures in all such patients were modified in 2005–2007 to recommend routine collection in only the sickest patients.1, 2 Using a national sample of emergency department (ED) visits, we examined patterns of obtaining cultures in adults hospitalized with community-acquired pneumonia.

Clinical Usefulness of Routine Use of Anaerobic Blood Culture Bottle

Background: Blood culture for diagnosis of bacter- emia and fungemia comprises aerobic and anaerobic cultures. The clinical utility of routine anaerobic blood culture has been questioned for a long time and was evaluated in this study. Methods: A total of 9,028 positive blood cultures were collected...

Comparing Resistant Microorganisms Isolated from Patients and Environment in an Intensive Care Unit

Background: Recently, the probable involvement of surfaces from the hospital environment as a disseminating source of resistant bacteria has been highlighted. The aim of the study was to compare resistant microorganisms isolated from inanimate surfaces, equipments and patient blood culture samples in an Intensive Care Unit from Belo Horizonte, Brazil. Methods: A cross-sectional study was performed from July to October 2009. Data sources were microbiologic samples from environment and patient blood culture. Duplicate samples were obtained by swabs from up to seven different touch sites around two different patients in four different days. Jointly with the environmental samples, bacterial isolates from an adult ICU patients’ routine blood cultures were obtained from hospital laboratory. The samples were identified, tested for sensitivity and compared by rep-PCR test to verify similarity. Results: Difference among the averages of Colony Forming Units was found within the environment samples (p < 0.004). In the environment were identified antibiotic resistant microorganisms such as Vancomycin resistant Enterococcus faecalis, imipenem and ciprofloxacin Pseudomonas aeruginosa and multidrug-resistant Acinetobacter baumannii. Similarities (60% -80%) were established among environmental and blood culture samples. Conclusion: The environmental sampling showed different averages of contamination of the surfaces and equipment. The similarity among the bacterial isolates of patients’ blood cultures and environmental samples reinforces the hypothesis of the horizontal transference of pathogens.

Rapid detection of Enterococcus spp. direct from blood culture bottles using Enterococcus QuickFISH Method: a multicenter investigation

The performance of a diagnostic method for detection and identification of Enterococcus spp. directly from positive blood culture was evaluated in a clinical study. The method, Enterococcus QuickFISH BC, is a second-generation peptide nucleic acid (PNA) fluorescence in situ hybridization (FISH) test, which uses a simplified, faster assay procedure. The test uses fluorescently labeled PNA probes targeting 16S rRNA to differentiate Enterococcus faecalis from other Enterococcus spp. by the color of the cellular fluorescence. Three hundred fifty-six routine blood culture samples were tested; only 2 discordant results were recorded. The sensitivities for detection of Enterococcus faecalis and non-faecalis Enterococcus were 100% (106/106) and 97.0% (65/67), respectively, and the combined specificity of the assay was 100%. The combined positive and negative predictive values of the assay were 100% (171/171) and 98.9% (185/187), respectively.