Diagnosis of community-acquired acute respiratory illness: From conventional microbiological methods to molecular detection (multiplex).

Investigations of the etiologic agents of community-acquired acute respiratory illness may lead to better treatment decisions and patient outcomes. In a routine care setting, we assessed the diagnostic performance of a multiplex PCR assay with respect to conventional microbiological methods, in a continuous series of adult cases of community-acquired acute respiratory illness. We enrolled 279 adult patients hospitalised for community-acquired acute respiratory illness at Tours University Hospital during the winter of 2011-2012. Respiratory samples (mostly nasopharyngeal aspirates) were studied prospectively by indirect immunofluorescence assay and multiplex PCR, that enable detection of 8 viruses and 21 respiratory pathogens respectively. In total, 255 of the 279 (91.4%) samples had interpretable results by both methods. At least one respiratory pathogen was detected by multiplex PCR in 171 specimens (65%). Overall, 130 (76%) of the 171 positive samples were positive for only one respiratory pathogen, 37 (22%) samples were positive for two pathogens and four (2%) were positive for three pathogens. With indirect immunofluorescence assay, a respiratory virus was detected in 27 of the 255 (11%) specimens. Indirect immunofluorescence assay detected some of the influenza virus A (15/51, 29%) infections identified by multiplex PCR and some (7/15, 47%) human metapneumovirus and (5/12, 42%) respiratory syncytial virus infections, but it did not detect all the adenovirus infections. Thus, access to multiplex molecular assays improves the diagnostic spectrum and accuracy over conventional methods, increasing the frequency of identification of the respiratory pathogens involved in community-acquired acute respiratory illness.

Pseudomonas aeruginosa in French hospitals between 2001 and 2011: back to susceptibility.

The European Antimicrobial Resistance Surveillance Network (EARS-Net) reported an increase in the rates of resistance of Pseudomonas aeruginosa to antimicrobials between 2008 and 2011 in France. This alarming report was based on data collected during the harmonisation of breakpoints by the European Committee on Antimicrobial Susceptibility Testing (EUCAST) committee. However, these data were not supported by the findings of other national surveillance networks. In this study, we assessed the trends in P. aeruginosa antimicrobial drug resistance at six French hospitals over a longer period of time (2001-2011) and with a constant definition of resistance. After the exclusion of incomplete data and duplicates, we sorted 34,065 isolates into the antimicrobial resistance patterns defined by the European Centre for Disease Prevention and Control (ECDC). The proportion of isolates with a resistant pattern (non-susceptible to one or two antimicrobial categories), a multidrug-resistant pattern (non-susceptible to three or four antimicrobial categories) or an extensively drug-resistant pattern (non-susceptible to five or six antimicrobial categories) decreased significantly over time. Logically, the proportion of isolates with a wild-type resistance pattern has increased significantly over the same period. No significant changes in the rates of resistance to cephalosporins and penicillins were observed, whereas carbapenem resistance rates increased. By contrast, the proportion of isolates resistant to fluoroquinolones, aminoglycosides and monobactams decreased significantly over time. In conclusion, our data do not confirm the EARS-net data, suggesting instead that antimicrobial drug resistance in P. aeruginosa might not have increased in French hospitals over the last decade.

[Lyme borreliosis: census of adult patients hospitalized in Indre-et-Loire (France), from the Hospital Discharge Data (1999-2006)]. / Borréliose de Lyme: recensement des cas adultes hospitalisés en Indre-et-Loire, à partir du PMSI (1999-2006).

BACKGROUND: To describe the clinical forms and epidemiology of Lyme borreliosis, in French adult patients hospitalized in Indre-et-Loire (Centre region). METHODS: Patients were recruited from standardized discharge summaries collected in the hospital database. All adult patients, hospitalized in public hospitals of the Indre-et-Loire administrative district, over a period of 8 years (1999-2006), who satisfied the European diagnostic criteria of Lyme borreliosis, were included. RESULTS: Encoding of Lyme borreliosis had a poor positive predictive value (65%). Forty-seven adult patients presented with the 50 following clinical forms: erythema migrans (n=5), neuroborreliosis (n=32), knee single-joint arthritis (n=4), acrodermatitis chronica atrophicans (n=3), carditis (n=2), ocular borreliosis (n=2), miscellaneous (n=2). Three patients had a combination of two different clinical forms. Meningoradiculitis was the most frequent neurologic manifestation. When a cranial nerve was involved, it was constantly the facial nerve, and mainly bilaterally. Few patients in our study had erythema migrans: these patients are usually treated in a general medicine setting. Although the incidence in the Centre region was lower than in some other regions of France and Europe, the clinical spectrum of the disseminated forms was similar. CONCLUSION: This cohort illustrates the diversity of clinical manifestations of Lyme borreliosis in hospitalized patients, particularly at disseminated and late stages as well as the complexity of its diagnosis and its epidemiological surveillance.

Blood pressure cuff as a potential vector of pathogenic microorganisms: a prospective study in a teaching hospital.

OBJECTIVE: To investigate the potential role of blood pressure (BP) cuffs in the spread of bacterial infections in hospitals. DESIGN: A comprehensive, prospective study quantitatively and qualitatively evaluating the bacterial contamination on BP cuffs of 203 sphygmomanometers in use in 18 hospital units from January through March 2003. SETTING: A university hospital with surgical, medical, and pediatric units. RESULTS: A level of contamination reaching 100 or more colony-forming units per 25 cm(2) was observed on 92 (45%) of inner sides and 46 (23%) of outer sides of 203 cuffs. The highest rates of contamination occurred on the inner side of BP cuffs kept in intensive care units (ICUs) (20 [83%] of 24) or on nurses' trolleys (27 [77%] of 35). None of the 18 BP cuffs presumed to be clean (ie, those that had not been used since the last decontamination procedure) had a high level of contamination. Potentially pathogenic microorganisms were isolated from 27 (13%) of the 203 BP cuffs: 20 of these microorganisms were Staphylococcus aureus, including 9 methicillin-resistant strains. The highest rates of contamination with potentially pathogenic microorganisms were observed on cuffs used in ICUs and those kept on nurses' trolleys. For 4 patients with a personal sphygmomanometer, a genetic link was found between the strains isolated from the BP cuffs and the strains isolated from the patients. CONCLUSIONS: The results of this survey highlight the importance of recognizing BP cuffs as potential vectors of pathogenic bacteria among patients and as a source of reinfection when dedicated to a single patient, emphasizing the urgent need for validated procedures for their use and maintenance.

Outbreak in France of Neisseria meningitidis B:15:P1.12 belonging to sequence type 1403.

This report describes a meningococcal outbreak in France caused by Neisseria meningitidis B:15:P1.12 of sequence type 1403, which affected eight young patients, between November 2000 and February 2002. Epidemiological typing confirmed that a single strain was responsible. Favourable outcome, sequelae or death resulted in similar proportions as in other cases of meningococcal disease in France during the same period, but purpura was observed in all eight cases. The patients were aged between 14 and 28 years, whereas the median age of patients affected by other meningococcal strains during this period in the same area was 60.4 years.

Identification of new phages to type Staphylococcus aureus strains and comparison with a genotypic method.

The aim of this study was to optimize the epidemiological monitoring of strains of Staphylococcus aureus, a major cause of hospital-acquired infections. From September to December 1998 47 S. aureus strains isolated from swabs taken from orthopaedic and trauma patients were in studied. Thirty-five isolates were sensitive to methicillin (MSSA) and 12 were methicillin-resistant (MRSA). Ten of the 47 isolates could not be phage-typed using the international set of typing phages: five of these isolates were MSSA and five were MRSA. These MRSA isolates, which were also not typeable by the phages currently recommended for phage-typing MRSA, were lysed by locally isolated experimental phages 584 and 1814. Phage 1814 lysed the gentamicin-resistant MRSA and phage 584 acted on the gentamicin-sensitive MRSA. Both new phages were inactive against the methicillin-sensitive isolates. Cloning of certain isolates was confirmed by macrorestriction genomic profiles obtained by pulsed-field gel electrophoresis analysis (PFGE). The results showed good discriminatory ability of antibiotic-resistance pattern phenotyping and phage-typing when the phages used were adapted to epidemic-associated MRSA strains.

Urinary excretion reflects lung deposition of aminoglycoside aerosols in cystic fibrosis.

Using nebulization to deliver aminoglycosides may be of benefit in cystic fibrosis (CF) patients colonized by Pseudomonas aeruginosa. However, one problem with this route is the absence of clinical parameters allowing estimation of the mass of drug deposited in the lungs (MDL). The aim of this study was to assess whether aminoglycoside excretion in the urine reflects the MDL. Fourteen studies were performed in seven CF patients. Amikacin was mixed with albumin labelled with 99mTc and nebulized with an ultrasonic nebulizer. The MDL was determined by the mass-balance technique. Urine was collected during the 24 h following inhalation and was assayed for amikacin by fluorescence polarization immunoassay (FPIA). The mean+/-SEM MDL was 14.0+/-2.2% of the nebulizer charge. The mean+/-SEM amount of amikacin excreted in the urine was 20.9+/-4.5 mg and correlated with the MDL (r=0.93; p=0.0001). There was, however, wide intersubject variability in both deposition and excretion in the urine. Monitoring excretion of aminoglycosides in the urine allows noninvasive estimation of the mass of drug deposited in the lung in cystic fibrosis patients, which might be useful to assess the dose-response relationship in groups of patients, but intersubject variability prevents its use for individual follow-up.

Ciprofloxacin pharmacokinetics in young cystic fibrosis patients after repeated oral doses.

Until recently, only compassionate use of ciprofloxacin in children with cystic fibrosis was possible despite limited pharmacokinetic data. We studied five subjects with cystic fibrosis and exacerbation of pulmonary infection. A 15 mg/kg b.i.d. regimen of oral ciprofloxacin was administered. On the 15th day, eight blood samples were collected and plasma concentrations were measured by HPLC. The actual dose administered ranged from 10 to 14 mg/kg b.i.d., due to the fixed-dosage formulation. Corresponding AUC0-12 ranged from 8.2 to 11.9 mg.h/L. Plasma concentrations were maintained above individual MICs for a median time of 12.7 h over 24 h. The median area under the inhibitory curve was 52.8, which is about half the proposed target value for ciprofloxacin in pulmonary infections with Gram-negative bacteria such as Pseudomonas aeruginosa. A higher dose, administered from a specific formulation to ensure precise dosing, must be given in order to obtain adequate concentrations in cystic fibrosis children.

Changes in microbial ecology and use of cloxacillin.

There is generally a positive correlation between antibiotic consumption and incidence of resistance to antibiotics used either for prophylaxis or therapy in human infections. This was not the case for two surgical wards in our hospital. A 15-year study showed that the incidence of methicillin-resistant Staphylococcus aureus (MRSA) was unrelated to cloxacillin consumption, and in fact fell after introduction into the two wards of an antibiotic policy based on cloxacillin. The two wards, a 90-bed orthopaedic unit and a 60-bed trauma unit, had an incidence of MRSA that has remained below the hospital average (23% in 1989, 32% in 1992). Before introduction of the policy the incidence of MRSA in 1977-1979 in the orthopaedic ward was 31%, and in the trauma ward 33%. In 1989 an investigation revealed no MRSA carriers in staff of either ward. In contrast, seven MRSA carriers were found among staff and patients of three other surgical units selected, because the percentage of MRSA isolated was above the average in our hospital. However, a different type of patient is found in these units, the treatment techniques differ and broader-spectrum antibiotics are used. In addition to the usual precautions regarding nursing care and isolation techniques, the best means of reducing MRSA epidemics is to reduce the reservoir of carriers. The fall in the MRSA infection rate in orthopaedic and traumatology wards can be explained by antibiotic policy but also by other infection control measures.

Epidemiology of Staphylococcus aureus in patients with cystic fibrosis.

Seven hundred and thirty-four isolates of Staphylococcus aureus, recovered from the sputum of 238 cystic fibrosis patients in six French hospitals, were characterized by esterase electrophoretic typing, capsular polysaccharide serotyping and phage typing and tested against 14 antibiotics for sensitivity. Thirty-four esterase electrophoretic types were found with a genotypic diversity coefficient of 0.91. Five hundred and forty-eight (78.7%) isolates produced capsular polysaccharide and 350 (50.3%) were type 8. Four hundred and sixty isolates (66.6%) were phage typable and 202 (28.2%) were lysed by group III bacteriophages. No esterase electrophoretic type, capsular type or phage type was specific to cystic fibrosis. Isolates belonged to a wide range of types, similar to strains acquired outside hospitals. Eighty-five patients had three or more consecutive isolates over at least 6 months. The ability of S. aureus to persist for long periods of time has been demonstrated in 73% of them. Methicillin-resistance was encountered among 73 strains (9.8%) which were also multiresistant. Two hundred and eighty-nine (39.9%) strains were sensitive to all antibiotics tested except to penicillin. Pristinamycin and co-trimoxazole were the most effective antibiotics. These results could contribute to the elaboration of a rational approach to the prophylaxis and therapy of respiratory staphylococcal infections in cystic fibrosis patients.

[Antibiotic therapy of pneumopathies in intensive care and protected distal bronchial samples]. / Antibiothérapie des pneumopathies en réanimation et prélèvement bronchique distal protégé (PBDP).

Bacteriology was performed on 57 specimens collected by the Wimberley protected catheter bronchoscopy technique (PCB) from 42 ventilated patients with severe head trauma hospitalized in the neurosurgical intensive care unit to determine the etiology of their pneumopathy. All patients had a nasotracheal tube upon arrival at the intensive care unit. For each sample, smears were examined and cultures under aerobic and anaerobic conditions as well as with CO2 were performed. In 34 (59%) of the 57 cases, examination of smears allowed rapid diagnosis and appropriate chemotherapy. In 47 (82%) cases, culture was positive, with a single pathogen being recovered in half of cases. The most prevalent organisms among the 75 species isolated were S. aureus (38%), P. aeruginosa (15%), Klebsiella (12%), Haemophilus (8%), and Pneumococcus (9%). Consistency with positive cultures of blood or pleural effusion samples was recorded in 92% of cases. Narrow spectrum antibiotic therapy can be chosen according to the results of PCB bacteriology and rapid automated antibiotic sensitivity testing obtained within 24 hours. PCB is therefore recommended in pulmonary infections in intensive care units.