Residual risk and retrospective analysis of transfusion-transmitted bacterial infection reported by the French National Hemovigilance Network from 2000 to 2008.

BACKGROUND: Regarding blood safety, transfusion-transmitted bacterial infection (TTBI) remains the most frequent infectious risk. The incidence of these episodes needs to be assessed and updated frequently to accurately manage this risk. STUDY DESIGN AND METHODS: TTBIs were reported by the French network of local correspondents in each hospital and blood center. The regional coordinator managed the investigation. A multidisciplinary expert group from the French National Agency of Medicine and Health Products Safety (ANSM) analyzed each TTBI according to a standardized scale of imputability and severity. Only cases with likely or certain imputability are reported in this study. RESULTS: In France, 18.0 × 10(6) red blood cell (RBC) products, 1.94 × 10(6) platelet concentrates (PCs), and 2.44 × 10(6) fresh-frozen plasma units were transfused throughout 2000 to 2008. The incidence of TTBI was 2.45, 24.7, and 0.39 per million blood components (BCs), PCs, and RBCs, respectively. For PCs, the incidences of severe (vital threat or death) and fatal TTBI were 13.4 and 5.14 per million, respectively. PCs were responsible for 87% of TTBIs. A total of 66.7% of the implicated bacteria were Gram positive, most of them belonging to the normal skin flora. A total of 33.3% of the other implicated bacteria were Gram negative. CONCLUSION: The French hemovigilance system provides an accurate estimate of the TTBI incidence during a period with diversion and improving skin disinfection but without bacterial detection screening. This tool would be able to evaluate further additional safety procedures like bacterial screening and pathogen reduction technology.

Value of Xpert MRSA/SA blood culture assay on the Gene Xpert® Dx System for rapid detection of Staphylococcus aureus and coagulase-negative staphylococci in patients with staphylococcal bacteremia.

The Xpert MRSA/SA BC assay was examined prospectively in patients with staphylococcal bacteremia including 6 patients with blood culture bottles inoculated with biological fluid (synovial fluid in 4 cases and peritoneal fluid in 2 cases). Among the 56 Staphylococci species isolated, 80.3% were coagulase-negative staphylococci (CoNS) and 19.7% were S. aureus. Methicillin susceptibility test results showed that 77.8% of isolates were methicillin-resistant CoNS (MRCoNS) and 22.2% of isolates were methicillin-susceptible CoNS (MSCoNS). Of 11 S. aureus isolates, 63.7% were methicillin-susceptible S. aureus (MSSA) and 36.3% were methicillin-resistant S. aureus (MRSA). Xpert MRSA/SA BC results showed that genotypic results were in concordance with phenotypic results in 94.6% of cases versus 5.4% of discordant cases. Of these 3 discordant cases, 1 S. aureus isolate had an MRSA phenotype and an SPA(+)mec(+)SCCmec(-) genotype and another S. aureus isolate was phenotypically MSSA and genotypically SPA(+)mec(+)SCCmec(-), and 1 S. epidermidis isolate was phenotypically MSCoNS and genotypically SPA(-)mec(+)SCCmec(-).

Phenotypic and biochemical comparison of the carbapenem-hydrolyzing activities of five plasmid-borne AmpC ß-lactamases.

The CMY-2, ACT-1, DHA-1, ACC-1, and FOX-1 enzymes are representative of five plasmid-mediated AmpC (pAmpC) ß-lactamase clusters. Resistance to imipenem has been reported in Enterobacteriaceae as a result of pAmpC expression combined with decreased outer membrane permeability. The aim of this study was to determine the role of different pAmpCs in carbapenem resistance and to define the structure/activity relationship supporting carbapenemase activity. The ampC genes encoding the five pAmpCs and the chromosomal AmpC of Escherichia coli EC6, which was used as a reference cephalosporinase, were cloned and introduced into wild-type E. coli TOP10 and OmpC/OmpF porin-deficient E. coli HB4 strains. The MICs of ß-lactams for the recombinant strains revealed that CMY-2, ACT-1, and DHA-1 ß-lactamases conferred a high level of resistance to ceftazidime and cefotaxime once expressed in E. coli TOP10 and reduced significantly the susceptibility to imipenem once expressed in E. coli HB4. In contrast, FOX-1 and ACC-1 enzymes did not confer resistance to imipenem. Biochemical analysis showed that CMY-2 ß-lactamase and, to a lesser extent, ACT-1 exhibited the highest catalytic efficiency toward imipenem and showed low K(m) values. A modeling study revealed that the large R2 binding site of these two enzymes may support the carbapenemase activity. Therefore, CMY-2-type, ACT-1-type, and DHA-1-type ß-lactamases may promote the emergence of carbapenem resistance in porin-deficient clinical isolates.

Characterization of CSP-1, a novel extended-spectrum beta-lactamase produced by a clinical isolate of Capnocytophaga sputigena.

The Capnocytophaga sputigena isolate NOR, responsible for septicemia, was resistant to amoxicillin and narrow-spectrum cephalosporins. In a cloning experiment, a new gene, bla(CSP-1), was identified; this gene encodes a novel extended-spectrum beta-lactamase (ESBL) that shares only 52% and 49% identities with the CME-1 and VEB-1 beta-lactamases, respectively. The G+C content of this gene, its genetic environment, the absence of conjugation transfer, and its detection in two reference strains suggested that it was an intrinsic resistance gene located on the chromosome.

First case of human spondylodiscitis due to Shewanella algae.

We present the first case of human spondylodiscitis due to Shewanella algae. Our patient did not have any predisposing factors. The portal of entry was probably a cutaneous lesion on the leg, exposed to seawater. Bacteria were isolated in pure culture from a needle biopsy specimen of the vertebral disk. Automated identification systems identified the organism as Shewanella putrefaciens. However, molecular biology identified it as S. algae. Treatment with ceftriaxone and amikacin, then ciprofloxacin successfully addressed the infection. We also review four published cases of human osteoarticular infections caused by Shewanella spp: two cases of arthritis and two cases of osteomyelitis. Two patients had predisposing factors, and contact with water was found in two cases. The clinical, radiological and biological characteristics of S. algae spondylodiscitis are indistinguishable from those of spondylodiscitis of other causes. A cutaneous lesion with exposure to water is a potential portal of entry. Molecular typing is necessary to obtain a precise bacteriological identification.

Assessment of Chlamydia trachomatis infection by Cobas Amplicor PCR and in-house LightCycler assays using PreservCyt and 2-SP media in voluntary legal abortions.

Chlamydial infection of the upper genital tract after abortion is well recognized, but routine screening for infection before termination is rare, and few centres are aware of the prevalence of post-abortion complications in their patient population. Knowledge of the patient population is the best guide for developing screening strategies. The aim of this study was to determine the prevalence of chlamydial infection in patients presenting for legal termination of pregnancy, and to assess the presence of Chlamydia trachomatis by PCR on specimens collected in either PreservCyt (ThinPrep) or 2-sucrose phosphate (2-SP) transport medium. Two hundred and eleven single, sexually active women, aged 15-26 years, attending the Gynaecology and Obstetric Hospital, Amiens, France, for surgical termination of pregnancy were enrolled in this study from June 2002 to June 2003. C. trachomatis detection using a Cobas Amplicor PCR test (Roche Diagnostics) targeting a 207 bp segment of the common cryptic plasmid and a quantitative LightCycler real-time PCR (LC-PCR) (Roche Diagnostics) targeting a 123 bp fragment within the highly conserved constant domain 3 of the single-chromosome-copy ompA gene were performed on endocervical swabs in 2-SP, and on specimens collected using a cytobrush and placed in PreservCyt medium. The in-house LC-PCR was used as a chromosomal diagnosis method and to determine the load of C. trachomatis. This method was able to detect the mutant Swedish variant with a deletion of 377 bp in the target area in the cryptic plasmid, which is the region targeted by the Cobas Amplicor PCR test. C. trachomatis was detected in 19/211 patients (9 %) by both PCR methods. Among the 19 infected women, C. trachomatis was detected by the Cobas Amplicor PCR in 16 specimens in PreservCyt (7.6 %) and in 12 endocervical swabs in 2-SP (5.7 %). Specimens from only nine women were PCR-positive in both PreservCyt and 2-SP media by this method. Cobas Amplicor PCR revealed that 10.9 and 2.3 % of the PreservCyt and 2-SP samples, respectively, contained inhibitors. The same 19 infected women were LC-PCR positive in both PreservCyt and 2-SP samples. No additional infected women were found by this last method; thus, it was concluded that none of the samples contained the new variant of C. trachomatis. The load in each sample varied from 10(2) to 10(7) copies ml(-1).

Molecular typing and characterization of extended-spectrum TEM, SHV and CTX-M beta-lactamases in clinical isolates of Enterobacter cloacae.

Sixty-one non-repetitive Enterobacter cloacae ESBL producers were collected at the Amiens University Hospital in France. Eight beta-lactam resistance phenotypes (a-h) and three aminoglycoside resistance phenotypes (i-k) were identified among these isolates, and 32 different pulsotypes were observed. Of these 61 isolates, 37 were sequenced and found to harbor beta-lactamases with a pI of 5.9 (TEM-4), 6.5 (TEM-24), 7.8 (SHV-4), 8.2 (SHV-12), 8.4 (CTX-M-1) and 8.0 (CTX-M-9). Four imipenem-resistant ESBL-producing E. cloacae isolates did not express the 38kDa OMP, indicating that this resistance is associated with porin deficiency.

Contribution of extended-spectrum AmpC (ESAC) beta-lactamases to carbapenem resistance in Escherichia coli.

ESAC beta-lactamases have increased catalytic efficiencies toward extended-spectrum cephalosporins and to a lesser extent toward imipenem as compared with the wild-type cephalosporinases. We show here that ESAC expression associated with the loss of both OmpC and OmpF porins conferred in Escherichia coli a high level of resistance to ertapenem and reduced the susceptibility to imipenem. On the contrary, ESAC expressed in the OmpC- or OmpF-deficient E. coli strains or narrow-spectrum cephalosporinase expressed in the OmpC-and OmpF-deficient strain do not confer reduced susceptibility to any of the carbapenems. The production of ESAC beta-lactamase in favorable E. coli background may represent an additional mechanism of resistance to ertapenem.

Molecular characterization of AmpC-producing Escherichia coli clinical isolates recovered in a French hospital.

OBJECTIVES: To characterize the AmpC-type beta-lactamases produced by Escherichia coli clinical isolates. METHODS: E. coli isolates recovered in a French hospital in 2006 were selected on the basis of a resistance phenotype consistent with increased AmpC production. The presence of genes coding for plasmid-mediated cephalosporinases as well as the existence of mutations in the chromosome-borne ampC genes was studied by PCR and sequencing. Genes for chromosomal cephalosporinases were cloned and the conferred resistance patterns were analysed. The isolates were submitted to phylotyping and genotyping analysis. RESULTS: Thirty-four out of 2800 E. coli isolates were selected. Sixteen isolates, which overexpressed their chromosomal wild-type cephalosporinases due to mutations into their promoter sequence, were susceptible to extended-spectrum cephalosporins (ECLs). Eighteen isolates, mostly of the commensal phylogenetic group A or B1, had reduced susceptibility to ECLs, due to the production of chromosomal extended-spectrum AmpC (ESAC) beta-lactamases, or plasmid-mediated cephalosporinases (CMY-2 and ACC-1), or to combined mechanisms of resistance. Sequence analysis showed that ESAC beta-lactamases had amino acid changes in the R2 binding site, among which was a novel structural change corresponding to the duplication of Ile-283 in the H-9 helix. All the E. coli clinical isolates were non-clonally related except for four CMY-2-producing strains. CONCLUSIONS: This work sheds new light on the spread of ESAC beta-lactamases in E. coli. It showed that this emerging mechanism of resistance could be as frequent as plasmid-mediated cephalosporinases (0.21% and 0.28% of the E. coli isolates, respectively) and that a phenotypic approach is not able to identify these mechanisms of resistance.

Nocardia nova as the causative agent in spondylodiscitis and psoas abscess.

We describe here the first case of Nocardia nova spondylodiscitis accompanied by a psoas abscess due to spreading from pulmonary nocardiosis. Nocardia was cultured from all affected sites. After 1 year of an appropriate antimicrobial therapy and a surgical drainage of the abscess that was required, the patient's clinical condition had improved.

community-acquired infection with healthcare-associated methicillin-resistant Staphylococcus aureus: the role of home nursing care.

OBJECTIVE: To better understand the role of indirect transmission in community-acquired infection with methicillin-resistant Staphylococcus aureus (MRSA). DESIGN: Prospective case-control study. SETTING: A French teaching hospital. PATIENTS: A total of 198 case patients and 198 control patients with MRSA or methicillin-susceptible S. aureus infection diagnosed between April 2002 and July 2003. RESULTS: Multivariate analysis showed a highly significant independent link between MRSA infection at admission and prior receipt of home nursing care (odds ratio [OR], 3.7; P<.001). Other independent risk factors were prior hospitalization (OR, 3.8; P<.001), transfer from another institution (OR, 2.3; P=.008), and age older than 65 years (OR, 1.6; P=.04). Prior home nursing care showed a frequency dose-response relationship. Eleven MRSA-infected patients had had home nursing procedures but no hospital stay in the previous 3 years. These patients' MRSA strains were related to the prevalent MRSA clone currently spreading in French hospitals. CONCLUSION: Home nursing care appears to be an independent risk factor for MRSA acquisition in the community. The reservoir probably consists of MRSA carriers discharged from the hospital. Community nurses seem to be a potential vector.

Lymph node biopsy specimens and diagnosis of cat-scratch disease.

We report microbiologic analysis of 786 lymph node biopsy specimens from patients with suspected cat-scratch disease (CSD). The specimens were examined by standard, cell culture, and molecular methods. Infectious agents were found in samples from 391 (49.7%) of 786 patients. The most commonly identified infectious agent was Bartonella henselae (245 patients, 31.2%), the agent of CSD. Mycobacteriosis was diagnosed in 54 patients (6.9%) by culture and retrospectively confirmed by using a specific real-time PCR assay. Neoplasm was diagnosed in 181 specimens suitable for histologic analysis (26.0%) from 47 patients. Moreover, 13 patients with confirmed Bartonella infections had concurrent mycobacteriosis (10 cases) or neoplasm (3 cases). A diagnosis of CSD does not eliminate a diagnosis of mycobacteriosis or neoplasm. Histologic analysis of lymph node biopsy specimens should be routinely performed because some patients might have a concurrent malignant disease or mycobacteriosis.

Molecular characterisation and mechanisms of resistance of multidrug-resistant human Salmonella enterica serovar Typhimurium isolated in Amiens (France).

Antimicrobial resistance patterns of Salmonella enterica serovar Typhimurium isolates obtained during the study period were examined. The molecular epidemiology and the mechanisms of resistance to ampicillin, chloramphenicol and tetracycline were investigated. Resistance to ampicillin increased from 59% between 1996 and 1999 to 62.5% in 2000 and to 66.6% in 2001. Of 51 S. Typhimurium isolates studied, 100% were resistant to ampicillin (minimum inhibitory concentration (MIC)>256 mg/L) and sulphonamide (MIC range, 128 to >256 mg/L). Ninety-eight percent of isolates were resistant to streptomycin (MIC range, 48-256 mg/L), 92.2% to tetracycline (MIC range, 32 to >256 mg/L), 88.2% to chloramphenicol (MIC>256 mg/L), 21.5% to sulphamethoxazole/trimethoprim (MIC>32 mg/L), 5.8% to amoxicillin/clavulanic acid (MIC, 32 mg/L) and 1.9% to cefalothin (MIC, 64mg/L). Six resistance phenotypes were found (a-f), with phenotypes a (47%) and b (27.5%) being predominant. Twenty-five (49%) of 51 isolates produced a single beta-lactamase, among which 48% produced PSE-1, 44% produced TEM-1 and 8% produced OXA-1. Among 26 of the 51 isolates, 10 produced PSE-1+OXA-1, 7 produced TEM-1+PSE-1+OXA-1, 6 produced TEM-1+PSE-1, and 3 produced TEM-1+OXA-1. Forty-eight (94.1%) of the 51 isolates had the plasmid-mediated resistance gene flo(ST) to chloramphenicol and tetracycline. Combining enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) and pulsed-field gel electrophoresis (PFGE), 16 distinct patterns were identified, among which patterns IA (35.3%) and IF (27.4%) were considered as epidemic patterns. The dendrogram obtained from S. Typhimurium pulsotypes allowed five clones (S1-S5) to be identified, with two prevalent clones comprising 47.8% (S2) and 27.3% (S4) of the isolates.

Combined detection of Chlamydia trachomatis-specific antibodies against the 10 and 60-kDa heat shock proteins as a diagnostic tool for tubal factor infertility: Results from a case-control study in Cameroon.

A case-control study was conducted to determine the diagnostic value of Chlamydia trachomatis-associated anti-Chsp10 and/or anti-Chsp60 antibodies in the detection of secondary infertility. There were significant associations between C. trachomatis infection and infertility (p<0.01), and between C. trachomatis-specific anti-Chsp10 or anti-Chsp60 antibodies and secondary infertility (p<0.001). A significant correlation was found between anti-Chsp10 and anti-Chsp60 titers (p<0.01). The detection of either C. trachomatis-associated anti-Chsp10 or anti-Chsp60 antibodies cumulatively allowed specific diagnosis of secondary infertility (57.4% sensitivity, 75.5% specificity).

Assessment of Chlamydia trachomatis infection in asymptomatic male partners of infertile couples.

Three specimens from 111 asymptomatic male partners of infertile couples attending the Department of Urology in Amiens, France, were examined by the PCR COBAS AMPLICOR test (Roche Molecular Diagnostics) for the presence of Chlamydia trachomatis. The specimens analysed were: first void urine (FVU), urine obtained after prostatic massage (UPM) and semen specimens. Serum from each patient was also obtained and analysed for the presence of IgG and IgA chlamydial antibodies by in-house microimmunofluorescence (MIF) and pELISA. C. trachomatis was detected by PCR in 5.4% of FVU samples, 2.7% of semen specimens and in 0.9% of UPM samples. Two treatments for processing the samples (storage at -70 degrees C and heating to 95 degrees C) were routinely used before initial testing to reduce the effects of inhibitors of PCR. Despite these precautions, the PCR method revealed the presence of inhibitors in 7.3% of semen specimens and 3.6% of FVU samples. C. trachomatis was detected by PCR COBAS AMPLICOR in seven of 111 patients (6.3%) and by serology in five of 111 patients (4.5%). The detection of C. trachomatis in FVU, UPM and semen specimens can serve as a marker for the presence of this organism in the genital tract, and can be used as a reliable way of detecting asymptomatic carriers of infection.

Prevalence of Chlamydia pneumoniae infection in squamous cell carcinoma of the head and neck.

On the basis of epidemiological data, an association between Chlamydia pneumoniae (Cp) infection and head and neck cancer might be suggested. The aim of the present study was to detect Cp-DNA within tumour tissue specimens by a two-step polymerase chain reaction. Investigation was planned on the Fleming's procedure for early termination when initial results were extreme. So, after ten consecutive patients, only one tumour contained Cp-DNA. Hence the prevalence could be regarded as inferior to 60% (2a=b=0.08), the threshold under which a direct role of Cp in head and neck cancer development does not seem to be likely.

Effectiveness of gentamicin-impregnated cement in the prevention of deep wound infection after primary total knee arthroplasty.

Effectiveness of gentamicin-impregnated cement in preventing deep wound infection after total knee arthroplasty (TKA) was estimated using data from prospective surveillance. In multivariate analysis, the protective effect of gentamicin-impregnated cement on the development of infection was close to the limit of significance. Gentamicin-impregnated cement may prevent TKA infections.

Molecular epidemiology of ampicillin-resistant clinical isolates of Salmonella enterica serovar Typhimurium.

Thirty-nine multiresistant Salmonella enterica serovar Typhimurium (S. Typhimurium) isolates were obtained from 33 children and 6 adults hospitalized from 1996 to 1999 in the University Hospital of Amiens (France). S. Typhimurium was cultured from stools (n=36), blood samples (n=2) and peritoneal fluid (n=1). These isolates were characterized by biotyping, antibiotic susceptibility test, RAPD-PCR, and PFGE typing. Emergence of pentaresistant S. Typhimurium isolates (phenotype ACSSuTe) was observed, and five of them were resistant to nalidixic acid and of intermediate susceptibility to pefloxacin. Genotypic analysis of both RAPD and PFGE results showed that there were 7 different patterns. Thirty-three isolates gave an identical pattern (AI) and were considered as epidemic isolates; the six remaining patterns (each containing one isolate) corresponded to sporadic cases. Antibiotic susceptibility patterns, RAPD and PFGE patterns subdivided the 39 isolates into 9 clonally related groups. One of them (pattern AI and R-pattern a) was implicated in 74% of the cases.