Molecular-based diagnosis of bacteremia in the setting of fever with or without neutropenia in pediatric hematology-oncology patients.

BACKGROUND: Prompt evaluation and appropriate treatment with wide-spectrum antibiotics is considered mandatory for febrile oncology patients especially during neutropenia. Central venous catheters are widely used in pediatric oncology patients and are often the source of infections. Patients are usually admitted for follow-up and administration of antibiotics. Aims were to assess the efficacy of the polymerase chain reaction (PCR) method in identifying bacteria in blood samples as compared with standard blood cultures. METHODS: This was a prospective study, which included all patients with central venous catheters admitted to the pediatric hematology-oncology department over the 14-month period. Demographic, clinical, and laboratory variables were compared in bacteremic and nonbacteremic patients. Standard microbiological cultures were compared using the PCR technique. RESULTS: From September 2004 to November 2005, 148 blood cultures (70 patients) were evaluated. Positive blood cultures were detected on 21 (18.3%) occasions. PCR had sensitivity of 46%, specificity of 98%, positive predictive value 86%, and negative predictive value 89%. The PCR identified fastidious bacteria in 2 occasions when standard cultures were negative. CONCLUSIONS: Inspite of low sensitivity, PCR may help with early identification of bacteremia. Improving this technology is warranted.

Diagnostic accuracy of PCR alone compared to galactomannan in bronchoalveolar lavage fluid for diagnosis of invasive pulmonary aspergillosis: a systematic review.

PCR in bronchoalveolar lavage (BAL) fluid has not been accepted as a diagnostic criterion for invasive pulmonary aspergillosis (IPA). We conducted a systematic review assessing the diagnostic accuracy of PCR in BAL fluid with a direct comparison versus galactomannan (GM) in BAL fluid. We included prospective and retrospective cohort and case-control studies. Studies were included if they used the EORTC/MSG consensus definition criteria of IPA and assessed ≥80% of patients at risk for IPA. Two reviewers abstracted data independently. Risk of bias was assessed using QUADAS-2. Summary sensitivity and specificity values were estimated using a bivariate model and reported with a 95% confidence interval (CI). Nineteen studies published between 1993 and 2012 were included. The summary sensitivity and specificity values (CIs) for diagnosis of proven or probable IPA were 90.2% (77.2 to 96.1%) and 96.4% (93.3 to 98.1%), respectively. In nine cohort studies strictly adherent to the 2002 or 2008 EORTC/MSG criteria for reference standard definitions, the summary sensitivity and specificity values (CIs) were 77.2% (62 to 87.6%) and 93.5% (90.6 to 95.6%), respectively. Antifungal treatment before bronchoscopy significantly reduced sensitivity. The diagnostic performance of PCR was similar to that of GM in BAL fluid using an optical density index cutoff of 0.5. If either PCR or GM in BAL fluid defined a positive result, the pooled sensitivity was higher than that of GM alone, with similar specificity. We conclude that the diagnostic performance of PCR in BAL fluid is good and comparable to that of GM in BAL fluid. Performing both tests results in optimal sensitivity with no loss of specificity. Results are dependent on the reference standard definitions.

Incidence and risk factors for endocarditis among patients with health care-associated Staphylococcus aureus bacteraemia.

BACKGROUND: Staphylococcus aureus infective endocarditis (IE) is a characteristic community-acquired infection, however most cases are presently occurring in the health care setting. This study investigated the incidence and risk factors for S. aureus IE in patients with nosocomial and health care-associated S. aureus bacteraemia (SAB). METHODS: Consecutive patients with health care-associated and hospital-acquired SAB were prospectively recruited over a 30-month period. Patients were followed up for at least 12 weeks after the initial positive blood culture result. The primary endpoint was the diagnosis of IE. RESULTS: IE occurred in 11 of 303 patients (3.6%). Patient characteristics at diagnosis and that were associated with IE included the number of positive blood cultures obtained during hospitalization (p = 0.003), the duration of bacteraemia (p < 0.001), bacteraemia persisting for > 3 days (odds ratio (OR) 14.5, 95% confidence interval (CI) 4.0-52.8; p < 0.001), performance of echocardiography (OR 1.88, 95% CI 1.69-2.1; p = 0.001), presence of a well known predisposing risk for IE (OR 57.2, 95% CI 13.6-240.5; p < 0.001), a non-fatal McCabe score (OR 2.10, 95% CI 1.4-3.1; p = 0.02), and the duration of fever related to the infection (p = 0.026). On multivariable analysis, the presence of a predisposing risk for IE, prolonged bacteraemia, and non-fatal McCabe score remained significantly associated with IE. CONCLUSIONS: In this study the incidence of IE was lower than previously reported. Three clinical characteristics were identified as risk factors for IE among patients with SAB acquired in a health care setting.

Outcome of Pneumocystis jirovecii pneumonia diagnosed by polymerase chain reaction in patients without human immunodeficiency virus infection.

BACKGROUND AND OBJECTIVE: Pneumonia caused by Pneumocystis jirovecii (PCP) in patients without human immunodeficiency virus (HIV) infection is associated with high mortality. The diagnosis of PCP at our institution is based on detection of DNA using a polymerase chain reaction (PCR) assay. The aim of this study was to describe the clinical manifestations, outcomes and factors associated with mortality due to PCP, as diagnosed by PCR, in patients without HIV infection. METHODS: Over a 6-year period, all HIV-negative immunocompromised patients suspected of having an opportunistic pulmonary infection underwent diagnostic bronchoscopy. A multigene PCR assay that detects Pneumocystis jirovecii DNA was used for the diagnosis of PCP. Patients were considered to have PCP if they had underlying immunodeficiency, compatible signs and symptoms, abnormal radiological findings, and Pneumocystis jirovecii DNA was detected in a bronchoalveolar lavage fluid sample. Data was collected retrospectively. RESULTS: PCP was diagnosed in 58 patients. The underlying conditions included haematological malignancies (60.3%), solid tumours (17.2%) and immunosuppressive treatment (22.4%). The most common clinical features in patients with PCP were fever (94.6%), dyspnoea (67.2%) and cough (36.2%). The overall in-hospital mortality was 17.2% (10/58). Mortality was associated with co-infections, high lactate dehydrogenase levels, female gender, and higher pneumonia severity index and acute physiology and chronic health evaluation III scores. CONCLUSIONS: In this study, the mortality of HIV-negative patients with PCP was low compared with previous reports. We hypothesize that this finding resulted from the increased sensitivity of a PCR-based assay, as compared with traditional methods, for the diagnosis of PCP in HIV-negative patients.

[Isolated congenital asplenia--a rare cause of severe pneumococcal sepsis].

Invasive disease caused by Streptococcus pneumoniae (SPn) is common among young children. Severe sepsis can be seen among those with primary or secondary immunodeficiency states. The absence of a spleen is a well-known risk factor for severe and overwhelming pneumococcal sepsis, as well as other encapsulated bacteria (e.g. Haemophilus influenzae type b (Hib), or Neisseria meningitidis). The most common cause of asplenia is surgical removal of the spleen (after trauma or as a treatment for various hematological conditions). Dysfunction of the spleen can also be seen in sickle cell disease, with high risk of invasive bacterial diseases. Primary congenital asplenia is rare. Congenital asplenia can be a part of Ivemark syndrome which is accompanied by other malformations. Isolated congenital asplenia is exceedingly rare. These patients can present with severe sepsis, meningitis or even sudden death. Overall, 31 cases have been reported, among them 17 were familial and the rest sporadic. The genetic bases for this rare life-threatening malformation are not known. The authors describe a one year old patient, presented with severe pneumococcal sepsis and multisystem organ failure. Isolated congenital asplenia was demonstrated. The child recovered and is being treated according to the recommendations for adults with asplenia.

Early-onset group B Streptococcus sepsis in high risk neonates born after prolonged rupture of membranes.

BACKGROUND: According to the U.S. Centers for Disease Control guidelines, prolonged rupture of membranes mandates intrapartum antimicrobial prophylaxis for group B Streptococcus whenever maternal GBS status is unknown. OBJECTIVES: To evaluate the local incidence, early detection and outcome of early-onset GBS sepsis in neonates born at 35-42 weeks gestation after PROM to women with unknown GBS status who were not given intrapartum antimicrobial prophylaxis. METHODS: During a 1 year period we studied all neonates born beyond 35 weeks gestation with maternal PROM > or =18 hours, unknown maternal GBS status and without prior administration of IAP. Complete blood count, C-reactive protein, blood culture and polymerase chain reaction amplification of bacterial 16S rRNA gene were performed in blood samples collected immediately after birth. Unfavorable outcome was defined by one or more of the following: GBS bacteremia, clinical signs of sepsis, or positive PCR. RESULTS: Of the 3616 liveborns 212 (5.9%) met the inclusion criteria. Only 12 (5.7%) of these neonates presented signs suggestive of sepsis. PCR was negative in all cases. Fifty-eight neonates (27.4%) had CRP > 1.0 mg/dl and/or complete blood count abnormalities, but these were not significantly associated with unfavorable outcome. Early-onset GBS sepsis occurred in one neonate in this high risk group (1/212 = 0.47%, 95% CI 0.012-2.6). CONCLUSIONS: In this single-institution study, the incidence of early-onset GBS sepsis in neonates born after PROM of 18 hours, unknown maternal GBS status and no intrapartum antimicrobial prophylaxis was 0.47%.

Acremonium vertebral osteomyelitis: molecular diagnosis and response to voriconazole.

We present a case of Acremonium vertebral osteomyelitis that relapsed despite surgical debridement and prolonged treatment with liposomal amphotericin B, but which responded to voriconazole therapy. The report highlights the role of molecular diagnosis of rare fungal osteomyelitis. The patient was successfully treated with voriconazole.

Infected subgaleal hematoma in a neonate.

Subgaleal hematoma (SGH) is an infrequent finding in neonates, occurring mostly after vacuum extraction deliveries. SGH can cause anemia, hypovolemic shock, and death. To date, only one case of neonatal infected SGH has previously been reported. We describe a term neonate with severe polymicrobial infection complicating SGH, including anaerobic bacteria, and with unique imaging features.

Meningitis following spinal anesthesia: 6 cases in 5 years.

We describe 6 cases of meningitis after spinal anesthesia associated with a single anesthesiologist over the course of 5 years. The earliest case occurred in 2000, and the other 5 cases occurred over the course of 14 months in 2004-2005. The case identified in 2000 was culture-positive for Streptococcus salivarius. The other 5 cases were culture-negative for this organism but in 2 cases, the cerebrospinal fluid was found to be positive for bacterial DNA that was identified as belonging to S. salivarius by sequencing of the 16S rRNA gene. The association with a single anesthesiologist and a single hospital during a relatively short interval, however, lead us to believe that these occurrences are part of a series associated with possible violations of aseptic technique.

Contamination of peripheral hematopoeitic stem cell products with a Mycobacterium mucogenicum-related pathogen.

A gram-positive rod with a restriction pattern closely related to the published nucleotide sequence of Mycobacterium mucogenicum was isolated from 6 of 45 units of peripheral blood stem cell products. The source of the contamination was traced to ice cubes used in processing the peripheral blood stem cell products. Substituting reusable ice trays for ice from an ice machine terminated the outbreak.

Molecular identification of Exiguobacterium acetylicum as the aetiological agent of bacteraemia.

A case of catheter-related bacteraemia caused by Exiguobacterium acetylicum is reported in an elderly patient. The availability of sequence-based methods facilitated rapid identification and expanded the spectrum of diseases attributed to coryneform bacteria and specifically to the genus Exiguobacterium.

Periopathogenic bacteria in persistent periapical lesions: an in vivo prospective study.

BACKGROUND: The aim of this in vivo prospective study was to detect the presence of periopathogenic bacteria in persistent periapical lesions and to compare the reliability of two different methods: anaerobic culture and the DNA hybridization technique. METHODS: Samples were obtained from 24 patients with persistent periapical lesions referred for surgical endodontic treatment. A sterile paper point was inserted into the periapical lesion for 10 seconds. The point was stored in sterile transfer tubes and analyzed by DNA hybridization. Tissue samples were transported in transfer medium and analyzed further using anaerobic culture. RESULTS: At least one periodontal pathogenic bacterium was found in seven of 24 cases. Bacterial species present were Treponema denticola (three cases), Porphyromonas gingivalis (three cases), Tannerella forsythensis (four cases), Prevotella intermedia (one case), and Actinobacillus actinomycetemcomitans (three cases). No particular signs or symptoms were associated with the presence of these bacterial species. Anaerobic culture failed to identify any of the periopathogenic bacteria. CONCLUSIONS: Periodontal pathogenic bacterial DNA can be detected in persistent periapical lesions. Anaerobic cultures failed to detect the periodontal pathogenic bacteria in positive hybridization assays, suggesting that standard culture methods lack sensitivity or that hybridization assays are flawed with low specificity. The clinical significance of the presence of bacterial DNA in persistent periapical lesions remains to be determined.

Evidence of periopathogenic microorganisms in placentas of women with preeclampsia.

BACKGROUND: Periodontal disease is a chronic inflammatory infectious disease that may act as a focus of infection. Preeclampsia is a pregnancy-specific hypertensive disorder that often leads to maternal morbidity and mortality. Acute atherosis, the placental lesion of preeclampsia, shares many histopathological features with atherosclerosis. Recently, chronic infection was linked to the initiation of atherosclerosis. Oral pathogens have been detected in atherosclerotic plaques, where they may play a role in the development and progression of atherosclerosis. The purpose of the present study was to explore the possibility that periopathogenic bacteria may translocate into the placental tissues of women with preeclampsia. METHODS: Samples were taken from 16 placentas obtained from cesarean sections of women with preeclampsia and from 14 age-matched healthy pregnant women. Polymerase chain reaction was used to detect Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum ssp., Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Treponema denticola. RESULTS: Eight of the 16 (50%) placenta specimens were positive for one or more periopathogenic bacteria in the preeclampsia group, compared to only two of the 14 samples (14.3%) from controls. Bacterial counts were statistically significantly higher in the preeclampsia group for all of the periopathogenic bacteria examined (P

Aspergillus vertebral osteomyelitis in chronic leukocyte leukemia patient diagnosed by a novel panfungal polymerase chain reaction method.

BACKGROUND CONTEXT: Vertebral osteomyelitis and disciitis caused by Aspergillus spp is a rare event. Early diagnosis and early antifungal therapy are critical in improving the prognosis for these patients. The diagnosis of invasive fungal infections is, in many cases, not straightforward and requires invasive procedures so that histological examination and culture can be performed. Furthermore, current traditional microbiological tests (ie, cultures and stains) lack the sensitivity for diagnosis of invasive aspergillosis. PURPOSE: To present a case of vertebral osteomyelitis caused by Aspergillus spp diagnosed using a novel polymerase chain reaction (PCR) assay. STUDY DESIGN: Case report. METHODS: Aspergillus DNA was detected in DNA extracted from the necrotic bone tissue by using a "panfungal" PCR novel method. RESULTS: Treatment with voriconazole was started based on the diagnosis. CONCLUSION: Using this novel technique enabled us to diagnose accurately an unusual bone pathogen that requires a unique treatment.

Prolonged fever and splinter hemorrhages in an immunocompetent traveler with disseminated histoplasmosis.

We present a case of progressive disseminated histoplasmosis in an immunocompetent traveler. Histoplasmosis was acquired in South America; its manifestations included prolonged fever, splinter hemorrhages, erythema multiforme, arthritis, and mediastinal lymphadenopathy. To the best of our knowledge no splinter hemorrhages had previously been reported in a patient with histoplasmosis.

Eradication of carbapenem-resistant Enterobacteriaceae gastrointestinal colonization with nonabsorbable oral antibiotic treatment: A prospective controlled trial.

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) are emerging. In attempt to eradicate CRE colonization, we conducted a semirandomized, prospective, controlled trial using oral nonabsorbable antibiotics. METHODS: Consecutive hospitalized CRE carriers were studied. Patients whose rectal isolates were gentamicin sensitive but colistin resistant were treated with gentamicin. Patients whose isolates were colistin sensitive but gentamicin resistant were treated with colistin. Patients whose isolates were sensitive to both drugs were randomized to 3 groups of oral antibiotic treatment: gentamicin, colistin, or both. Patients whose isolates were resistant to both drugs, and those who did not consent, were followed for spontaneous eradication. RESULTS: One hundred fifty-two patients were included; 102 were followed for spontaneous eradication for a median duration of 140 days (controls), and 50 received 1 of the 3 drug regimens: gentamicin, 26; colistin, 16; both drugs, 8, followed for a median duration of 33 days. Eradication rates in the 3 treatment groups were 42%, 50%, and 37.5%, respectively, each significantly higher than the 7% spontaneous eradication rate in the control group (P < .001, P < .001, and P = .004, respectively) with no difference between the regimens. No significant adverse effects were observed. CONCLUSION: Oral antibiotic treatment with nonabsorbable drugs to which CRE is susceptible appears to be an effective and safe for eradication of CRE colonization and, thereby, may reduce patient-to-patient transmission and incidence of clinical infection with this difficult-to-treat organism.