Impact of a change in protected environment on the occurrence of severe bacterial and fungal infections in children undergoing hematopoietic stem cell transplantation.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a procedure with a high infection risk. Strict isolation of patients is the rule to prevent such condition. OBJECTIVE: We compared the occurrence of severe infections (bacteremia and invasive fungal infection, IFI) in children undergoing alloHSCT before and after the move to a new protected unit with decreases in isolation methods. METHODS: The study was conducted over a 10-year period. Unit 1 (2002-2007) consisted of laminar airflow rooms where caregivers were required to wear a sterile outfit (gown, gloves, hat, and mask). Unit 2 (2008-2012) included spacious positive air pressure rooms with HEPA filters where only a clean gown and mask were required to be worn. RESULTS: Two hundred eighty-six alloHSCTs were performed (144 in Unit 1 and 142 in Unit 2). We reported a total incidence of 4.78 infections/1000 hospital-days including 4.4 episodes of bacteremia and 0.38 episodes of IFI. There was no statistical difference in the incidence of infections: n = 4.98/1000 hospital-days in Unit 1 vs. n = 4.6/1000 in Unit 2 (P = 0.63). CONCLUSION: The lack of difference in the occurrence of severe infection supports our decision to decrease unnecessary high protection in alloHSCT units to improve children's daily life.

Specific real-time polymerase chain reaction places Kingella kingae as the most common cause of osteoarticular infections in young children.

BACKGROUND: The use of universal 16S rDNA polymerase chain reaction (PCR) has recently shown that the place of Kingella kingae in osteoarticular infections (OAI) in young children has been underestimated, but this technique is not the most sensitive or the most rapid method for molecular diagnosis. We developed a specific real-time PCR method to detect K. kingae DNA and applied it to the etiologic diagnosis of OAI. PATIENTS AND METHODS: All children admitted to a pediatric unit for OAI between January 2004 and December 2005 were enrolled in this prospective study. Culture-negative osteoarticular specimens were tested by 16S rDNA PCR and by K. kingae-specific real-time PCR when sufficient sample remained. RESULTS: By culture alone, a pathogen was identified in 45% of the 131 specimens tested (Staphylococcus aureus, n = 25; K. kingae, n = 17; others, n = 18). 16S rDNA PCR and K. kingae-specific PCR were both applied to 61 of the culture-negative samples. The combination of culture and 16S rDNA PCR identified a pathogen in 61% of cases (K. kingae DNA, n = 16; DNA of other microorganisms, n = 5). Specific real-time PCR identified a further 6 cases caused by K. kingae and confirmed all 16 universal PCR-positive cases, bringing the overall documentation rate to 66%. K. kingae was the leading cause of OAI in this pediatric series (n = 39, 45%), followed by S. aureus (n = 25, 29%) CONCLUSION: The K. kingae-specific real-time PCR places K. kingae as the leading cause of OAI in children at our hospital.

Keep an Ear Out for Francisella tularensis: Otomastoiditis Cases after Canyoneering.

We report here three unusual cases of otomastoiditis due to Francisella tularensis, complicated by cervical abscesses and persistent hearing loss, plus facial paralysis for one patient. Intriguingly, the three patients had practiced canyoneering independently in the same French river, between 2009 and 2014, several days before clinical symptoms onset. The results point out that fresh water exposure may be a potential contamination route for tularemia. Besides, due to the frequent complications and sequelae, we believe that F. tularensis should be considered as a possible etiology in case of otitis media, failure of the conventional antibiotic treatment, and suspicious exposure of the bacteria.

Contribution of a broad range polymerase chain reaction to the diagnosis of osteoarticular infections caused by Kingella kingae: description of twenty-four recent pediatric diagnoses.

BACKGROUND: Microbiologic diagnosis of septic arthritis and osteomyelitis in children is hindered by the less than optimal yield of blood and osteoarticular fluid cultures. PATIENTS AND METHODS: All patients admitted to a pediatric unit for osteoarticular infections (OAI) between January 2001 and February 2004 were enrolled in this prospective study. Osteoarticular fluid and biopsy samples that were negative by conventional culture were tested by polymerase chain reaction (PCR) with universal 16S ribosomal DNA primers. RESULTS: We enrolled 171 children. Culture was positive in 64 cases (37.4%), yielding Kingella kingae in 9 cases. The 107 culture-negative specimens were tested by 16S ribosomal DNA PCR. Fifteen samples (14%) were positive, all for Kingella DNA sequences. K. kingae was the second cause of OAI in this population (30.4%), after Staphylococcus aureus (38%). Patients with Kingella infection diagnosed by culture (9 cases) did not differ from those diagnosed by PCR (15 cases) in terms of their clinical characteristics (including prior antibiotic therapy). The characteristics of the 24 children with arthritis (n = 17) or osteomyelitis (n = 7) were similar to those reported elsewhere. Fever (>38 degrees C) and symptom onset shortly before hospitalization (median, 4.5 days) were significantly associated with arthritis. CONCLUSION: Use of molecular diagnostic methods increases the identification of K. kingae in osteoarticular infections.

Sustained ex vivo skin antiseptic activity of chlorhexidine in poly(epsilon-caprolactone) nanocapsule encapsulated form and as a digluconate.

In this work, the sustained bactericidal activity of chlorhexidine base loaded poly(epsilon-caprolactone), PCL, nanocapsules against Staphylococcus epidermidis inoculated onto porcine ear skin was investigated. Drug loaded nanocapsules were prepared by the interfacial polymer deposition following solvent displacement method, then characterized by photon correlation spectroscopy, electrophoretic measurements, transmission and scanning electron microscopy. Antimicrobial activity of these colloidal carriers was evaluated (i) in vitro against eight strains of bacteria, and (ii) ex vivo against Staphylococcus epidermidis inoculated for 12 h onto porcine ear skin surface treated for 3 min either with 0.6% chlorhexidine base loaded or unloaded nanocapsules suspended in hydrogel, or 1% chlorhexidine digluconate aqueous solution. Chlorhexidine absorption into the stratum corneum (SC) was evaluated by the tape-stripping method. The results showed that chlorhexidine nanocapsules in aqueous suspension having a 200-300 nm size and a positive charge exhibited similar minimum inhibitory concentrations against several bacteria with chlorhexidine digluconate aqueous solution. Ex vivo, there was a significant reduction in the number of colony forming units (CFUs) from 3-min treated skin with chlorhexidine nanocapsule suspension (5 to <1 log(10)) compared to chlorhexidine digluconate solution (5 to 2.02 log(10)) after a 8-h artificial contamination. After a 12-h artificial contamination, both formulations failed to achieve a 5 log(10) reduction. Furthermore, from a 3-min treatment with an identical applied dose and a subsequent 12-h artificial contamination, a residual chlorhexidine concentration in the SC was found to be three-fold higher with chlorhexidine nanocapsule suspension than with chlorhexidine digluconate solution. Interestingly, nanocapsules were shown in porcine skin follicles. Consequently, a topical application of chlorhexidine base-loaded positively charged nanocapsules in an aqueous gel achieved a sustained release of bactericide against Staphylococcus epidermidis for at least 8 h. Enhancement of drug delivery by mediating a more direct and prolonged contact between the carrier and (i) bacteria, (ii) skin surface, and (iii) skin follicles was assumed.

Viral and bacterial pathogens identification in children hospitalised for severe pneumonia and parapneumonic empyema.

Pneumonia is caused by respiratory bacteria and/or viruses. Little is known if co-infections are an aggravating factor in hospitalised children with severe pneumonia. We studied the impact of respiratory pathogens on the severity of pneumonia. Between 2007 and 2009, 52 children hospitalised with a well-documented diagnosis of community-acquired pneumonia (CAP), with or without parapneumonic empyema (PPE), were enrolled in the study. The patients were classified into 2 groups: CAP + PPE (n = 28) and CAP (n = 24). The identification of respiratory viruses and bacteria in nasopharyngeal aspirates and pleural effusion samples were performed using conventional bacterial techniques and molecular assays. Using real-time multiplex PCR and antigen detection, Streptococcus pneumoniae was the main agent identified in 76% of the cases by molecular tests and BinaxNOW® in pleural fluid. A total of 8% of pleural fluid samples remained undiagnosed. In nasopharyngeal aspirates, rhinovirus, parainfluenza viruses, human metapneumovirus, and respiratory syncytial virus were detected in both CAP and CAP + PPE populations; however, the percentage of viral co-detection was significantly higher in nasopharyngeal aspirates from CAP + PPE patients (35%) compared with CAP patients (5%). In conclusion, viral co-detection was observed mainly in patients with more severe pneumonia. Molecular biology assays improved the pathogens detection in pneumonia and confirmed the S. pneumoniae detection by BinaxNOW® in pleural effusion samples. Interestingly, the main S. pneumoniae serotypes found in PPE are not the ones targeted by the heptavalent pneumococcal conjugate vaccine.

Kingella kingae: osteoarticular infections of the sternum in children: a report of six cases.

PURPOSE: Kingella kingae is increasingly recognized as a pathogen of osteoarticular infections (OAI) below the age of 2 years. It was reported that bones and joints which are rarely infected by other pathogens were frequently invaded by K. kingae. Based on a series of six cases, we present the typical clinical and paraclinical manifestation of K. kingae infections of the sternum and sterno-manubrial joint. METHODS: A review of the clinical, laboratory, radiological, microbiological, and molecular data of six consecutive children admitted to a paediatric unit for OAI of the sternum was done. RESULTS: Culture alone allowed for the detection of K. kingae as the responsible pathogen in three cases, molecular methods in the three other cases. Clinical and laboratory findings, as well as imaging methods, proved to be useful in the diagnostic process. CONCLUSION: Our findings suggest that infections of the lower sternum and the junction between the manubrium and the xyphoid process are typical, if not pathognomonic, for the organism. A respective diagnostic and therapeutic protocol was established.

Specific identification of Staphylococcus aureus by Staphychrom II, a rapid chromogenic staphylocoagulase test.

We compared the performance of Staphychrom II (International Microbio, Signes, France), a rapid (2-h) chromogenic staphylocoagulase test that uses human prothrombin and protease inhibitors, with those of the reference tube coagulase test (TCT) and the latex agglutination test (LAT) Slidex Staph Plus for the rapid identification of S. aureus. Prospective evaluation with 293 fresh clinical isolates yielded sensitivities, specificities, and predictive and negative predictive values of 98.1, 100, 100, and 95.1%, respectively, for the Staphychrom II test; 98.6, 98.7, 99.6, and 96.3%, respectively, for LAT; and 97.6, 98.7, 99.5, and 93.9%, respectively, for TCT. The perfect specificity of the Staphychrom II test was confirmed by testing 193 collection strains selected because of their potential testing pitfalls. The Staphychrom II test was positive for 90% of the 215 S. aureus strains tested after only 1 h of incubation. The Staphychrom II test was as sensitive as the reference TCT and was 100% specific.