Curbing methicillin-resistant Staphylococcus aureus in 38 French hospitals through a 15-year institutional control program

BACKGROUND: The Assistance Publique-Hôpitaux de Paris (AP-HP) institution administers 38 teaching hospitals (23 acute care and 15 rehabilitation and long-term care hospitals; total, 23 000 beds) scattered across Paris and surrounding suburbs in France. In the late 1980s, the proportion of methicillin resistance among clinical strains of Staphylococcus aureus (MRSA) reached approximately 40% at AP-HP.METHODS: A program aimed at curbing the MRSA burden was launched in 1993, based on passive and active surveillance, barrier precautions, training, and feedback. This program, supported by the strong commitment of the institution, was reinforced in 2001 by a campaign promoting the use of alcohol-based hand-rub solutions. An observational study on MRSA rate was prospectively carried out from 1993 onwards. RESULTS: There was a significant progressive decrease in MRSA burden (-35%) from 1993 to 2007, whether recorded as the proportion (expressed as percentage) of MRSA among S aureus strains (41.0% down to 26.6% overall; 45.3% to 24.2% in blood cultures) or incidence of MRSA cases (0.86 down to 0.56 per 1000 hospital days). The MRSA burden decreased more markedly in intensive care units (-59%) than in surgical (-44%) and medical (-32%) wards. The use of ABHR solutions (in liters per 1000 hospital days) increased steadily from 2 L to 21 L (to 26 L in acute care hospitals and to 10 L in rehabilitation and long-term care hospitals) following the campaign. CONCLUSION: A sustained reduction of MRSA burden can be obtained at the scale of a large hospital institution with high endemic MRSA rates, providing that an intensive program is maintained for a long period

Rectal Carriage of Extended-Spectrum Beta-Lactamase-Producing Gram-Negative Bacilli in Community Settings in Madagascar

BACKGROUND: Extended-spectrum ß-lactamase-producing Enterobacteria (ESBL-PE) emerged at the end of the 1980s, causing nosocomial outbreaks and/or hyperendemic situations in hospitals and long-term care facilities. In recent years, community-acquired infections due to ESBL-PE have spread worldwide, especially across developing countries including Madagascar. OBJECTIVES: This study aimed to determine the prevalence and risk factors of intestinal carriage of ESBL-PE in the community of Antananarivo. METHODS: Non-hospitalized patients were recruited in three health centers in different socio economic settings. Fresh stool collected were immediately plated on Drigalski agar containing 3 mg/liter of ceftriaxone. Gram-negative bacilli species were identified and ESBL production was tested by a double disk diffusion (cefotaxime and ceftazidime +/- clavulanate) assay. Characterization of ESBLs were perfomed by PCR and direct sequencing . Molecular epidemiology was analysed by Rep-PCR and ERIC-PCR. RESULTS: 484 patients were screened (sex ratio  = 1.03, median age 28 years). 53 ESBL-PE were isolated from 49 patients (carrier rate 10.1%). The isolates included Escherichia coli (31), Klebsiella pneumoniae (14), Enterobacter cloacae (3), Citrobacter freundii (3), Kluyvera spp. (1) and Pantoae sp.(1). In multivariate analysis, only the socioeconomic status of the head of household was independently associated with ESBL-PE carriage, poverty being the predominant risk factor. CONCLUSIONS: The prevalence of carriage of ESBL in the community of Antananarivo is one of the highest reported worldwide. This alarming spread of resistance genes should be stopped urgently by improving hygiene and streamlining the distribution and consumption of antibiotics

Assessment of Microbial Diversity in Biofilms Recovered from Endotracheal Tubes Using Culture Dependent and Independent Approaches

Ventilator-associated pneumonia (VAP) is a common nosocomial infection in mechanically ventilated patients. Biofilm formation is one of the mechanisms through which the endotracheal tube (ET) facilitates bacterial contamination of the lower airways. In the present study, we analyzed the composition of the ET biofilm flora by means of culture dependent and culture independent (16 S rRNA gene clone libraries and pyrosequencing) approaches. Overall, the microbial diversity was high and members of different phylogenetic lineages were detected (Actinobacteria, beta-Proteobacteria, Candida spp., Clostridia, epsilon-Proteobacteria, Firmicutes, Fusobacteria and gamma-Proteobacteria). Culture dependent analysis, based on the use of selective growth media and conventional microbiological tests, resulted in the identification of typical aerobic nosocomial pathogens which are known to play a role in the development of VAP, e.g. Staphylococcus aureus and Pseudomonas aeruginosa. Other opportunistic pathogens were also identified, including Staphylococcus epidermidis and Kocuria varians. In general, there was little correlation between the results obtained by sequencing 16 S rRNA gene clone libraries and by cultivation. Pyrosequencing of PCR amplified 16 S rRNA genes of four selected samples resulted in the identification of a much wider variety of bacteria. The results from the pyrosequencing analysis suggest that these four samples were dominated by members of the normal oral flora such as Prevotella spp., Peptostreptococcus spp. and lactic acid bacteria. A combination of methods is recommended to obtain a complete picture of the microbial diversity of the ET biofilm

Evaluation of βLACTA™ test, a rapid test detecting resistance to third-generation cephalosporins in clinical strains of Enterobacteriaceae.

Since decades, third-generation cephalosporins (3GC) are major drugs to treat infections due to Enterobacteriaceae; growing resistance to these antibiotics makes important to rapidly detect such resistance. βLACTA™ test is a chromogenic test developed for detecting within 15 minutes 3GC-resistant isolates from cultures on solid media. A multi-center prospective study conducted in 5 French and Belgian hospitals evaluated the performances of this test on clinical isolates. Based on antibiotic susceptibility testing, strains resistant or intermediate to cefotaxime or ceftazidime were classified as 3GC-resistant and molecular characterization of this resistance was performed. The rate of 3GC-resistance was globally 13.9% (332/2387), 9.4% in Escherichia coli (132/1403), 25.6% in Klebsiella pneumoniae (84/328), 30.3% in species naturally producing inducible AmpC beta-lactamases (109/360), and 5.6% in Klebsiella oxytoca and Citrobacter koseri (7/124). The overall sensitivity and specificity of βLACTA™ test were 87.7% and 99.6% respectively, were 96 and 100% for E. coli and K. pneumoniae and were 67.4% and 99.6% for species naturally producing inducible AmpC beta-lactamase. False negative results were mainly related to 3GC-resistant strains producing AmpC beta-lactamase. Interestingly, the test was positive for all 3GC-resistant extended-spectrum beta-lactamase producing isolates (n=241). Positive predictive value was 97% and would remain ≥ 96% for prevalence of 3GC-resistance ranging between 10 and 30%. Negative predictive value was 99% for E. coli and K. pneumoniae and 89% for the species producing inducible AmpC beta-lactamase.In conclusion βLACTA™ test was found to be easy to use and efficient to predict resistance to third-generation cephalosporins, particularly in extended-spectrum beta-lactamase producing strains

Partition locus-based classification of selected plasmids in Klebsiella pneumoniae, Escherichia coli and Salmonella enterica spp.: An additional tool

International audienceThe dissemination of antimicrobial resistance genes in Enterobacteriaceae has been largely attributed to plasmids, circular DNA molecules capable of autonomous replication. Whereas high-copy-number plasmids primarily rely on passive diffusion for plasmid maintenance, low-copy-number plasmids utilize so-called partition (par) systems. Plasmid partition relies on three structures, i.e. a centromere like DNA site, a centromere-binding protein and an ATPase or a GTPase motor protein for plasmid positioning. Identification and classification of plasmids is essential for tracing plasmids conferring drug resistance. PCR-based replicon typing is currently the standard method for plasmid identification but there are new classification schemes, especially the relaxase gene typing (PRaseT). Here we developed a multiplex PCR set targeting par loci found on the plasmids most frequently encountered in Enterobacteriaceae. This method, called “plasmid partition gene typing” (PAR-T), was validated with 136 transconjugants or transformants harboring various replicon types. The method was tested with 30 multidrug-resistant clinical isolates including Escherichia coli, Klebsiella pneumoniae and Salmonella enterica subsp. enterica carrying 1-4 replicons; all replicons were tested in parallel with PRaseT for comparison. Six multiplex PCRs and one simplex PCR including 18 pairs of primers recognized plasmids of groups IncA/C, FIA, FIB, FIC, FIIk, FII, HI1, HI2, I1, L/M, N, X. Our set of multiplex PCRs showed high specificity for the classification of resistance plasmids except for IncX replicons

Genetic Context of Plasmid-Carried blaCMY-2-Like Genes in Enterobacteriaceae▿ †

Analysis of 15 European clinical Enterobacteriaceae isolates showed that differences in the genetic context of blaCMY-2-like genes reflected the replicon type, usually IncA/C or IncI1. These blaCMY-2 loci may originate from the same ISEcp1-mediated mobilization from the Citrobacter freundii chromosome as structures described in earlier studies

Molecular epidemiology of ESBL-producing E. coli and K. pneumoniae: establishing virulence clusters

Laure Surgers,1,2 Peter Boersma,3 Pierre-Marie Girard,1,4 Audrey Homor,5 Delphine Geneste,2 Guillaume Arlet,2,5 Dominique Decré,2,5 Anders Boyd4 1Infectious Diseases Department, Saint-Antoine Hospital, APHP, Paris, France; 2Sorbonne University, INSERM, U1135, Centre d’Immunologie et des Maladies Infectieuses, CIMI Team 13, Paris, France; 3Department of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA; 4INSERM, Sorbonne Université, Institut Pierre Louis d’Épidémiologie et de Santé Publique, Paris, France; 5Bacteriology Department, Saint-Antoine Hospital, APHP, Paris, France Objective: To genetically characterize clusters of virulence factors (VFs) among extended spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae and assess whether these clusters are associated with genetic determinants or clinical outcomes. Methods: One hundred forty-eight E. coli and 82 K. pneumoniae clinical isolates were obtained from 213 patients in Paris, France. Isolates underwent ESBL characterization, MultiLocus Sequence Typing (MLST) typing and phylogenetic group identification. Detection of ten E. coli and seven K. pneumoniae VF-encoding genes were assessed, from which a k-medians partition algorithm with Jaccard similarity measure was used to construct clusters. Results: CTX-M was the predominant ESBL and susceptibility to trimethoprim–sulfamethoxazole (32%), ciprofloxacin (22%) and aminoglycosides (32%) was low. In E. coli, there were five identified clusters, with significantly different distributions of ESBL-sequence type (P<0.001), ST131 (P<0.001) and phylogenetic group (P=0.001) between clusters. “Siderophore exclusive”, “siderophore exclusive with iroN ” and “adhesin sfa/papGIII-rich” clusters had higher 12-month mortality rates compared to others (49% vs 22%, respectively, P=0.02). In K. pneumoniae, three different clusters, with significantly different distributions of aminoglycoside-sensitivity (P<0.004), MLST-type (P<0.001) and relaxase plasmids (P=0.001) were described. Conclusion: Distinct clusters of E. coli and K. pneumoniae VFs are observed within ESBL-producing isolates and are strongly associated with several genetic determinants. Their association with overall morbidity and mortality requires further evidence. Keywords: ESBL, virulence, mortality, E. coli, K. pneumonia

Klebsiella pneumoniae necrotizing fasciitis of the leg in an elderly French woman

Marguerite Monié,1 Laurence Drieux,2–4 Bernadette Nzili,1 Michèle Dicko,5 Catherine Goursot,1 Sandrine Greffard,6 Dominique Decré,3,4,7 Anthony Mézière1 1Assistance Publique-Hôpitaux de Paris (AP-HP), GHU Pitié Salpêtrière-Charles Foix, site Charles Foix, Service de Soins de Suite et Réadaptation orthogériatrique et polyvalent, Fondation d’Heur et Chemin Delatour, Ivry s/Seine, 2Assistance Publique-Hôpitaux de Paris, Hôpital Charles-Foix, Bactériologie-Hygiène, Paris, 3Sorbonne Universités, UPMC Univ Paris 06, CR7, Centre d’Immunologie et des Maladies Infectieuses, CIMI, team E13 (Bacteriology), Paris, 4INSERM, U1135, Centre d’Immunologie et des Maladies Infectieuses, CIMI, team E13 (Bacteriology), Paris, 5AP-HP, GHU Henri Mondor, Département de Médecine Interne et Gériatrie, Créteil, 6AP-HP, GHU Pitié Salpêtrière-Charles Foix, site Pitié Salpêtrière, Service de Médecine Gériatrique, Paris, 7AP-HP, Hôpital Saint-Antoine, Bactériologie-Hygiène, Paris, France Abstract: Klebsiella pneumoniae necrotizing fasciitis is a rare infection in regions outside of Asia. Here, we present a case of necrotizing fasciitis of the leg caused by K. pneumoniae in a 92-year-old French woman hospitalized in a geriatric rehabilitation unit. The patient initially presented with dermohypodermitis of the leg that developed from a dirty wound following a fall. A few hours later, this painful injury extended to the entire lower limb, with purplish discoloration of the skin, bullae, and necrosis. Septic shock rapidly appeared and the patient died 9 hours after the onset of symptoms. The patient was Caucasian, with no history of travel to Asia or any underlying disease. Computed tomography revealed no infectious metastatic loci. Blood cultures showed growth of capsular serotype K2 K. pneumoniae strains with virulence factors RmpA, yersiniabactin and aerobactin. This rare and fatal case of necrotizing fasciitis caused by a virulent strain of K. pneumoniae occurred in a hospitalized elderly woman without risk factors. Clinicians and geriatricians in particular should be aware of this important albeit unusual differential diagnosis. Keywords: necrotizing fasciitis, Klebsiella pneumoniae, elderl