Recent actuality about Bacillus cereus and human milk bank: a new sensitive method for microbiological analysis of pasteurized milk.

Three cases of Bacillus cereus infection or colonization occurred in the same region in France, and milk from the milk bank was suspected as a possible common source of contamination. All Batches delivered to the three cases complied with the requirements of the bacteriological reference method recommended by good practices guidelines. Still, a retrospective analysis with a more sensitive method showed one batch to contain B. cereus, however straincomparison revealed no epidemiological link betweenisolates from patients and those from the milk. Consequently, in accordance with the precautionary principle, we developed a new sensitive method for the screening of pasteurized milk for pathogenic bacteria. From January 1 to August 31, 2017, 2526 samples of pasteurized milk were prospectively included in the study. We showed that a 20 mL sample of pasteurized milk incubated for 18 h at 37 °C under aerobic conditions was favoring the detection of B. Cereus. The nonconformity rate was 6.3% for the reference method and 12.6% for the improved method (p < 0.0001). Nonconformity was due to the presence of B. cereus in 88.5% of cases for the improved method and 53% of cases for the reference method (p < 0.0001). Thus our new method is improves the microbiological safety of the product distributed and only moderately increases the rate of bacteriological nonconformity .

Pharmacological study of cefoxitin as an alternative antibiotic therapy to carbapenems in treatment of urinary tract infections due to extended-spectrum-ß-lactamase-producing Escherichia coli.

Cefoxitin could be an alternative to carbapenems in extended-spectrum-beta-lactamase-producing Escherichia coli (ESBL-EC) infections. However, pharmacological and clinical data regarding cefoxitin are limited. Using a recent pharmacological model and the MICs of ESBL-EC collected from pyelonephritis, we determined the probabilities to reach four pharmacological targets: free cefoxitin concentrations above the MIC during 50% and 100% of the administration interval (T>MIC = 50% and T>MIC = 100%, respectively) and free cefoxitin concentrations above 4× MIC during 50% and 100% of the administration interval (T>4MIC = 50% and T>4MIC = 100%, respectively). Cefoxitin could be used to treat ESBL-EC pyelonephritis, but administration modalities should be optimized according to MICs in order to reach pharmacological targets.

Evaluation of the Andromas matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of aerobically growing Gram-positive bacilli.

Matrix-associated laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is a rapid and simple microbial identification method. Previous reports using the Biotyper system suggested that this technique requires a preliminary extraction step to identify Gram-positive rods (GPRs), a technical issue that may limit the routine use of this technique to identify pathogenic GPRs in the clinical setting. We tested the accuracy of the MALDI-TOF MS Andromas strategy to identify a set of 659 GPR isolates representing 16 bacterial genera and 72 species by the direct colony method. This bacterial collection included 40 C. diphtheriae, 13 C. pseudotuberculosis, 19 C. ulcerans, and 270 other Corynebacterium isolates, 32 L. monocytogenes and 24 other Listeria isolates, 46 Nocardia, 75 Actinomyces, 18 Actinobaculum, 11 Propionibacterium acnes, 18 Propionibacterium avidum, 30 Lactobacillus, 21 Bacillus, 2 Rhodococcus equi, 2 Erysipelothrix rhusiopathiae, and 38 other GPR isolates, all identified by reference techniques. Totals of 98.5% and 1.2% of non-Listeria GPR isolates were identified to the species or genus level, respectively. Except for L. grayi isolates that were identified to the species level, all other Listeria isolates were identified to the genus level because of highly similar spectra. These data demonstrate that rapid identification of pathogenic GPRs can be obtained without an extraction step by MALDI-TOF mass spectrometry.

One-day prevalence of asymptomatic carriage of toxigenic and non-toxigenic Clostridioides difficile in 10 French hospitals.

BACKGROUND: Asymptomatic faecal carriage of Clostridioides difficile has been widely evaluated, but its prevalence across a wide range of clinical departments and related risk factors are not well described. The objectives of the PORTADIFF study were to evaluate the prevalence and identifying risk factors leading to asymptomatic carriage of both toxigenic and non-toxigenic C. difficile. METHODS: The PORTADIFF study was a 1-day prevalence study carried out in 10 different French hospitals. Adult patients, who agreed to participate, were included in this study and provided a fresh stool sample. C. difficile strains isolated from carriage were characterized by polymerase chain reaction (PCR) detection of tcdA, tcdB, cdtA and cdtB, and PCR ribotyping. RESULTS: In total, 721 patients were included in this study. The median age was 73 years (range 18-101 years) and the male/female ratio was 1.06. C. difficile (either toxigenic or non-toxigenic strains) was isolated from 79 (11%) patients; 42 (5.8%) strains were toxigenic. The prevalence rates of asymptomatic carriage ranged from 5% on surgical wards to 19% on long-term care wards. The main risk factors associated with asymptomatic carriage were antibiotic treatment within the preceding 3 months (81.8% vs 53.7%; P<0.01), hospitalization within the preceding 2 months (55.8% vs 33%; P<0.01), cumulative duration of hospital stay before study inclusion (mean 50.1 vs 34.5 days; P<0.047), and hospitalization on a ward with high global incidence of C. difficile infection. CONCLUSION: Eleven percent of hospitalized patients were asymptomatic carriers of toxigenic or non-toxigenic C. difficile, and may constitute a potential reservoir of C. difficile strains.

Management of lactating breast abscesses by ultrasound-guided needle aspiration and continuation of breastfeeding: A pilot study.

INTRODUCTION: Needle aspiration of breast abscesses during lactation are currently recommended as an alternative to surgery only for moderate forms. In case of breast abscess, many patients stop breastfeeding on the advice of a health professional. We reviewed our experience of treatment of lactating breast abscesses by ultrasound-guided aspiration and suggest an algorithm of their management. We also analyzed the continuation of breastfeeding of these patients after advices from trained teams. MATERIEL AND METHODS: We conducted a retrospective study from April 2016 to April 2017, including 28 patients referred for a breast abscess during lactation at the Duroc Breast Imaging Center. A management by ultrasound-guided aspiration was proposed to each patient. We collected data about the breastfeeding between October 2018 and January 2019. RESULTS: A single aspiration was sufficient in 64.3% of cases. The delay between the occurrence of the abscess and the indication for drainage was significantly higher for patients who have needed finally surgical drainage (p = 0,0031). There were no difference of size of abscesses between patients receiving needle aspiration alone and those who have undergone surgery (p = 0,97). All patients who had been managed by needle aspiration continued breastfeeding after the treatment and 40% of the patients were still breastfeeding at 6 months. CONCLUSION: The management of lactating breast abscess by ultrasound-guided needle aspiration is an effective alternative to surgery. It appears to be effective regardless of the size of the abscess and is compatible with the continuation of breastfeeding. Our study has indeed shown that if they are well advised, the majority of patients continue breastfeeding so that it is essential that health professionals be better trained regarding the management of breastfeeding complications.

Epidemiology and clinical characteristics of Klebsiella spp. meningitis in France.

OBJECTIVES: To describe the epidemiology of Klebsiella spp. meningitis in France with respect to clinical and bacteriological data. METHODS: We performed a four-year multicenter, retrospective, observational study. The primary objective was to provide a clinical description of patients with Klebsiella spp. meningitis. Secondary objectives were to compare community-acquired meningitis and healthcare-associated meningitis and to analyze factors associated with mortality. RESULTS: We enrolled 131 patients with Klebsiella spp. meningitis. Eighty-two (62.6%) infections were reported following neurosurgery. Twenty-eight strains (21.4%) were resistant to third-generation cephalosporins (3GC). The median [IQR] cellularity was 980/mm3 [116-5550], the median protein level was 5.67 [1.62-9] g/L and the median CSF glucose level was 2.5 [0-3.4] mmol/L. The in-hospital mortality rate was 23.6%. Community-acquired meningitis isolates were more frequently susceptible to 3GC than isolates from healthcare-associated meningitis (89.2% versus 72%; P=0.04). Comorbidities reported for patients with community-acquired meningitis were mainly diabetes mellitus and liver cirrhosis. In multivariate analysis, focal neurological disorder at the time of diagnosis was the only factor associated with in-hospital mortality (P=0.01). CONCLUSIONS: Purulent meningitis caused by Klebsiella spp. needs to be considered in patients with community-acquired meningitis and preexisting conditions, as well as in case of meningitis following neurosurgical procedures.

Revisited distribution of nonfermenting Gram-negative bacilli clinical isolates.

Nonfermenting Gram-negative bacilli (NF-GNB) are ubiquitous environmental opportunistic bacteria frequently misidentified by conventional phenotypic methods. The aim of this study was to determine the distribution of NF-GNB species by 16 S rRNA gene sequencing (used as reference method) and to compare performances of biochemical tests and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). From nine French hospitals, 188 NF-GNB isolates (except P. aeruginosa and A. baumannii) were prospectively collected from 187 clinical samples between December 2008 and May 2009. By using the genotypic approach, 173 (92%) and 188 (100%) isolates were identified to the species and genus level, respectively. They covered 35 species and 20 genera, with a predominance of Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Pseudomonas putida group bacteria. Of the 173 species-level identified strains, concordant identification to the species-level was obtained for 75.1%, 83% and 88.9% of isolates with API 20 NE strip, the VITEK-2 (ID-GN card) system and MALDI-TOF-MS, respectively. By excluding S. maltophilia isolates accurately identified by the three methods, genus-level identification was much higher for MALDI-TOF-MS (92.9%), compared with API 20 NE and VITEK-2 (76.2% and 80.8%, respectively). In conclusion, MALDI-TOF-MS represents a rapid, inexpensive, and accurate tool for routine identification of NF-GNB in human clinical samples.

Population pharmacokinetics of cefazolin in critically ill children infected with methicillin-sensitive Staphylococcus aureus.

OBJECTIVES: Cefazolin is one of curative treatments for infections due to methicillin-sensitive Staphylococcus aureus (MSSA). Both growth and critical illness may impact the pharmacokinetic (PK) parameters. We aimed to build a population PK model for cefazolin in critically ill children in order to optimize individual dosing regimens. METHODS: We included all children (age < 18 years, body weight (BW) > 2.5 kg) receiving cefazolin for MSSA infection. Cefazolin total plasma concentrations were quantified by high-performance liquid chromatography. A data modelling process was performed with the software MONOLIX. Monte Carlo simulations were used in order to attain the PK target of 100% fT > 4 ×MIC. RESULTS: Thirty-nine patients with a median (range) age of 7 (0.1-17) years and a BW of 21 (2.8-79) kg were included. The PK was ascribed to a one-compartment model, where typical clearance and volume of distribution estimations were 1.4 L/h and 3.3 L respectively. BW, according to the allometric rules, and estimated glomerular filtration rate (eGFR) on clearance were the two influential covariates. Continuous infusion with a dosing of 100 mg/kg/day to increase to 150 mg/kg/day for children with a BW < 10 kg or eGFR >200 mL/min/1.73m2 were the best schemes to reach the PK target of 100% fT> 4 ×MIC. CONCLUSIONS: In critically ill children infected with MSSA, continuous infusion seems to be the most appropriate scheme to reach the PK target of 100 % fT > 4 ×MIC in children with normal and augmented renal function.

Risk factors for developing ESBL E. coli: can clinicians predict infection in patients with prior colonization?

BACKGROUND: Extended-spectrum ß-lactamase-producing Escherichia coli (ESBLEC) is an increasing cause of hospital-acquired infection. Risk factors for ESBLEC colonization and infection have been reported, but information is lacking about the risk factors for acquiring ESBLEC infection in patients with prior colonization. AIM: To identify risk factors for development of infection in patients colonized with ESBLEC. METHODS: A retrospective study was performed at Hôpital Necker-Enfants Malades, Paris from 2007 to 2010. A multi-variable model was created to compare a group of patients with nosocomial ESBLEC infection following documented ESBLEC colonization with a control group of patients colonized with ESBLEC (case-control design). FINDINGS: In total, 118 patients were included: 40 (26 adults, 14 children) with colonization and infection and 78 (51 adults, 27 children) with colonization alone. The median time from colonization to infection was 12.5 days [25-75% confidence interval (CI) 5-40]. ESBLEC infections included urinary tract infection (85%), bacteraemia (7.5%) and lower respiratory tract infection (7.5%). On multi-variate analysis, use of ß-lactam/ß-lactamase inhibitor prior to infection [odds ratio (OR) 3.2, 95% CI 1.073-9.864); P = 0.037] and urinary catheterization were reported as risk factors for ESBLEC infection in colonized patients (OR 5.2, 95% CI 1.984-13.569; P = 0.0008). CONCLUSION: Identification of these risk factors will be helpful to identify patients colonized with ESBLEC who will require antibiotics for ESBLEC in the case of nosocomial infection. Limiting the use of specific antibiotics and controlling the duration of urinary catheterization will be helpful for prevention of ESBLEC infection.

MALDI-TOF MS Andromas strategy for the routine identification of bacteria, mycobacteria, yeasts, Aspergillus spp. and positive blood cultures.

All organisms usually isolated in our laboratory are now routinely identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) using the Andromas software. The aim of this study was to describe the use of this strategy in a routine clinical microbiology laboratory. The microorganisms identified included bacteria, mycobacteria, yeasts and Aspergillus spp. isolated on solid media or extracted directly from blood cultures. MALDI-TOF MS was performed on 2665 bacteria isolated on solid media, corresponding to all bacteria isolated during this period except Escherichia coli grown on chromogenic media. All acquisitions were performed without extraction. After a single acquisition, 93.1% of bacteria grown on solid media were correctly identified. When the first acquisition was not contributory, a second acquisition was performed either the same day or the next day. After two acquisitions, the rate of bacteria identified increased to 99.2%. The failures reported on 21 strains were due to an unknown profile attributed to new species (9) or an insufficient quality of the spectrum (12). MALDI-TOF MS has been applied to 162 positive blood cultures. The identification rate was 91.4%. All mycobacteria isolated during this period (22) were correctly identified by MALDI-TOF MS without any extraction. For 96.3% and 92.2% of yeasts and Aspergillus spp., respectively, the identification was obtained with a single acquisition. After a second acquisition, the overall identification rate was 98.8% for yeasts (160/162) and 98.4% (63/64) for Aspergillus spp. In conclusion, the MALDI-TOF MS strategy used in this work allows a rapid and efficient identification of all microorganisms isolated routinely.

[Bordetella bronchiseptica-associated acute chest syndrome in a child with sickle cell disease]. / Syndrome thoracique aigu associé à une infection àBordetella bronchiseptica chez un enfant drépanocytaire.

We describe a case of acute chest syndrome associated with Bordetella bronchiseptica pneumonia in a child with sickle cell disease. B. bronchiseptica is recognized as an important pathogen of the respiratory tract for a large variety of animal species. This zoonotic agent has been frequently associated with chronic and recurrent infections. In humans, the bacterium acts as an opportunistic pathogen affecting mostly immunocompromised patients or those with preexisting respiratory diseases. This case and literature review provides an opportunity to discuss the risk factors, treatment, follow-up, and prevention of such zoonotic infections in the context of a lack of cross-protection of new pertussis vaccines.

[Epidemiology of patients harboring extended-spectrum beta-lactamase-producing enterobacteriaceae (ESBLE), on admission]. / Épidémiologie des patients porteurs d'entérobactéries sécrétrices de bêtalactamase à spectre élargi (EBLSE), à l'admission.

OBJECTIVE: The incidence of extended-spectrum beta-lactamase-producing enterobacteria (ESBLE) has regularly increased over the last few years. However, little is known about epidemiology of ESBLE carriers in France. The objective of this study was to determine the ESBLE carriers or infected patients profile, identified within 48 hours following hospital admission. DESIGN: This retrospective study included all patients admitted in 2006 and 2007 at the Necker-Enfants-Malades (NEM) teaching hospital, carrying or infected with ESBLE isolated within 48 hours following admission. The pediatric and adult populations were compared. RESULTS: There was no significant difference between pediatric and adult populations. Escherichia coli and Klebsiella pneumoniae were the two main species isolated, accounting respectively for 59.6 and 21.1 % of the 114 isolated strains. Among the 114 analyzed files, 24 patients (21 %) were known to be EBLSE carriers, 37 (32 %) were transferred from another hospital, including 16 from another country. Concerning the 54 (47 %) other patients, five (4 %) came from a country with high prevalence, and 44 (39 %) were treated for a chronic illness. Only five patients (4 %) carrying ESBLE did not have any usual risk factor for multidrug resistance (MDR) bacterial carriage. CONCLUSIONS: In our study, 4 % of patients carrying ESBLE admitted had no usual risk factor for MDR bacteria. Targeted screening of previous carriers, patients with chronic illness, transferred patients, or patients coming from country with high prevalence, would help to limit the spread of ESBLE.

[Optimized clinical use of vancomycin, a prospective observational study in a Paris teaching hospital]. / Optimisation de la prescription de la vancomycine : étude prospective observationnelle dans un centre hospitalo-universitaire parisien.

INTRODUCTION: Vancomycin is still the cornerstone of antibiotic therapy for patients with suspected or proven invasive methicillin resistant Staphylococcus aureus infections. However, clinical and pharmacodynamic studies underline that appropriate doses depend on the infection site, the patient's weight, his renal function, and the bacterial susceptibility. OBJECTIVE AND METHOD: In this prospective study made in a Paris teaching hospital, our two goals were to describe the modalities of infusion and serum concentration obtained during therapy, in our pediatrics and adults population. RESULTS: In our hospital, vancomycin was administered every eight hours in 83 % (97/102) of the cases and the doses used were 30 mg/kg per day in 67 % of cases (68/102). Serum trough levels reached 15 mcg/ml and 20 mcg/ml in 36 % and 18 % of cases respectively. Moreover, despite adequate doses, trough levels of 15 mcg/ml were obtained in only 40 % of cases. CONCLUSION: Vancomycin infusion use could be optimized, by defining optimal serum concentrations and monitoring made by a mobile team of infectious diseases specialists.

Identification of clinical coagulase-negative staphylococci, isolated in microbiology laboratories, by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and two automated systems.

A study was performed to compare matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS), linked to a recently engineered microbial identification database, and two rapid identification (ID) automated systems, BD Phoenix (Becton Dickinson Diagnostic Systems, France) and VITEK-2 (bioMérieux, Marcy L'Etoile, France), for the ID of coagulase-negative staphylococci (CoNS). Two hundred and thirty-four clinical isolates of CoNS representing 20 species were analyzed. All CoNS isolates were characterized by sodA gene sequencing, allowing interpretation of the ID results obtained using the respective database of each apparatus. Overall correct ID results were obtained in 93.2%, 75.6% and 75.2% of the cases with the MALDI-TOF-MS, Phoenix and VITEK-2 systems, respectively. Mis-ID and absence of results occurred in 1.7% and 5.1% of the cases with MALDI-TOF-MS, in 23.1% and 1.3% with the Phoenix, and in 13.7% and 0.9% with the VITEK-2 systems, respectively. In addition, with the latter automate, 10.3% of the IDs were proposed with remote possibility. When excluding the CoNS species not included in the databases of at least one of the three systems, the final percentage of correct results, Mis-ID and absence of ID were 97.4%, 1.3% and 1.3% with MALDI-TOF-MS, 79%, 21% and 0% with the Phoenix, and 78.6%, 10.3% and 0.9% with the VITEK-2 system, respectively. The present study demonstrates the robustness and high sensitivity of our microbial identification database used with MALDI-TOF-MS technology. This approach represents a powerful tool for the fast ID of clinical CoNS isolates.