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ABSTRACT: We evaluated, by an improved susceptibility testing method, the prevalence and significance of low-level glycopeptide resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolates, which belonged to a previously described, retrospective cohort of patients treated for orthopedic device-related infections (ODRI) at the Geneva University Hospital between 2000 and 2008. Fifty-seven individual or multiple isolates were retrieved from 41 ODRI patients for glycopeptide susceptibility and clonality studies, including 20 patients with prosthetic joint (PJ) and 21 with osteosynthesis (OS) MRSA infections. Low-level glycopeptide resistance was detected by elevated teicoplanin or/and vancomycin minimum inhibitory concentrations (MICs ≥4 mg/L), as determined by a previously validated combination of macrodilution and agar dilution assays of improved sensitivity. MRSA isolates with elevated teicoplanin MICs were detected in 20/41 (49 %) ODRI patients at the onset or during the course of glycopeptide therapy, namely, in 10 of 20 patients with PJ and 10 of 21 patients with OS infections. Only one isolate developed a concomitant increase in vancomycin MIC during therapy. 13/20 (65 %) glycopeptide-intermediate S. aureus (GISA)-infected patients, including 7/10 (70 %) with PJ and 6/10 (60 %) with OS, experienced treatment failure. In contrast, therapy failed in only 5/21 (24 %) ODRI patients with non-GISA isolates (p = 0.012), including 2/10 (20 %) with PJ and 3/11 (27 %) with OS infections. The emergence of low-level teicoplanin resistance could not be explained by teicoplanin administration, since only four patients received teicoplanin. The evaluation of low-level teicoplanin resistance may improve the detection of GISA isolates. Further studies are warranted to evaluate the impact of low-level teicoplanin resistance on the outcome of glycopeptide therapy.
European Journal of Clinical Microbiology 07/2012; · 2.86 Impact Factor
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ABSTRACT: Group B streptococcus (GBS) is a leading cause of infectious neonatal morbidity and mortality. Timely and accurate identification of colonized mothers is imperative so that antibioprophylaxis can be implemented during labour to reduce the risk of neonatal sepsis. We planned our study to analyse the diagnostic accuracy of an intrapartum PCR assay to identify GBS-colonized women and to allow the implementation of correct (i.e. at least 4 h) intrapartum antibiotic prophylaxis based on the PCR results. We included 695 women in labour who were tested for rectovaginal GBS carriage by culture and PCR. Women were also screened at 35-37 weeks of gestation. Intrapartum GBS colonization was 19.3%. Assay sensitivity was 81.0% for antenatal culture and 85.0% for intrapartum PCR; p 0.72. GBS colonization (n = 107) was known at least 4 h before delivery in 68 (64%) and 73 (68%) women based on antenatal culture and intrapartum PCR, respectively. Among 43 women delivering preterm, correct status was known at least 4 h before delivery in 10 (23%) and 32 (74%) women according to antenatal culture and intrapartum PCR, respectively. These results support the concept that GBS screening can be performed routinely during labour in a clinical setting. The intrapartum approach is at least as accurate as the antenatal screening, with the additional advantage of identifying women delivering preterm or not followed during pregnancy.
Clinical Microbiology and Infection 12/2011; 17(12):1786-91. · 4.54 Impact Factor
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The Journal of hospital infection 01/2011; 77(4):360-2. · 3.01 Impact Factor
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ABSTRACT: Strain D958, a methicillin-resistant Staphylococcus aureus strain with reduced susceptibility to vancomycin, was isolated from a 69-year-old Saudi male patient presenting with severe sepsis immediately after admission. Despite high serum levels of vancomycin, the same S. aureus strain was isolated from five blood culture sets during 1 week. Treatment failure under therapeutic levels of vancomycin prompted us to investigate the resistance profile of this strain in further detail. The MIC values for vancomycin as determined by Etest and microdilution were 3.0 and 2.0 mg/liter, respectively, and remained unchanged during the treatment course. The macro-Etest method showed a MIC of 4 mg/liter. The strain showed liquid vancomycin and lysostaphin MBCs of 2.0 and 5.0 mg/liter, respectively. The isolates were confirmed as heterogeneously vancomycin-intermediate S. aureus (hVISA) by vancomycin population analysis profile. The areas under these curves were similar for Mu3 and D958 for vancomycin and teicoplanin (ratio values were 1 and 1.1 for vancomycin and teicoplanin, respectively). Extensive genotyping and molecular characterization demonstrated that the strain harbored a staphylococcal cassette chromosome mec element (SCCmec) type III cassette and was of sequence type ST241, a single-locus variant of the successful multiresistant clone ST239. Microarray results demonstrated that D958 contained numerous resistance determinants (generally plasmid or phage encoded). These results suggest that this strain is constitutively expressing an altered susceptibility to vancomycin. Further studies are warranted to assess the clonal distribution of such strains displaying reduced susceptibility to vancomycin prior to any antimicrobial therapy.
Journal of clinical microbiology 06/2010; 48(6):2199-204. · 4.16 Impact Factor
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T Ferry,
I Uçkay,
P Vaudaux, P François,
J Schrenzel,
S Harbarth,
F Laurent,
L Bernard,
F Vandenesch,
J Etienne,
P Hoffmeyer,
D Lew
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ABSTRACT: The purpose of this study was to determine the clinical and microbiological risk factors for treatment failure of methicillin-resistant Staphylococcus aureus (MRSA) orthopedic device-related infection (ODRI). A retrospective cohort study of patients with MRSA ODRI who were treated at Geneva University Hospitals between 2000 and 2008 was undertaken. Stored MRSA isolates were retrieved for genetic characterization and determination of the vancomycin minimum inhibitory concentration (MIC). Fifty-two patients were included, of whom 23 (44%) had joint arthroplasty and 29 (56%) had osteosynthesis. All 41 of the retrieved MRSA isolates were susceptible to vancomycin (MIC <or= 2 mg/L) and 35 (85%) shared genetic characteristics of the South German clone (ST228). During a median follow-up of 391 days (range, 4-2,922 days), 18 patients (35%) experienced treatment failure involving MRSA persistence or recurrence. Microbiological factors such as infection with the predominant clone and a vancomycin MIC of 2 mg/L were not associated with treatment failure. Using a Cox proportional hazards model, implant retention (hazard ratio [HR], 4.9; 95% confidence interval [CI], 1.3-18.2; P = 0.017) and single-agent antimicrobial therapy (HR, 4.4; 95% CI, 1.2-16.3; P = 0.025) were independent predictors of treatment failure after debridement. Therapy using a combination of antimicrobials should be considered for patients with MRSA ODRI, especially when implant removal is not feasible.
European Journal of Clinical Microbiology 11/2009; 29(2):171-80. · 2.86 Impact Factor
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ABSTRACT: Uncertainty persists about risk factors for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections in Europe and the long-term efficacy of decolonization strategies. To evaluate risk factors for CA-MRSA in Geneva, Switzerland, a hospital-based, retrospective case-control study of 26 patients with CA-MRSA infection and 60 control patients was performed. To evaluate the long-term effect of a systematic decolonization strategy (with and without concomitant systemic antibiotic therapy) for CA-MRSA patients, a prospective cohort study of 79 patients with Panton-Valentine leukocidin-producing CA-MRSA isolates was conducted. Nationality other than European Union or Swiss (adjusted OR 6.09; 95% CI 1.07-34.65) and absence of healthcare contact (adjusted OR 0.11, 95% CI 0.02-0.59) were independent predictors of CA-MRSA infection. Forty-five cases were followed (median, 22 months) to assess the long-term efficacy of the decolonization strategy; 39/45 (86.7%) had no clinical relapse and were MRSA-negative at their last follow-up, whereas six remained MRSA-positive. Five of these six cases belonged to a family cluster. Decolonization rates were similar between infected patients and asymptomatic carriers (92.6% vs. 77.8%, p = 0.20). This study shows a lack of readily modifiable risk factors for CA-MRSA infection in this population, and suggests the potential usefulness of conducting decolonization procedures in a setting with sporadic CA-MRSA infection. Further studies are needed to elucidate the role of migration as a factor contributing to the emergence of CA-MRSA in Europe.
Clinical Microbiology and Infection 04/2009; 15(6):552-9. · 4.54 Impact Factor
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ABSTRACT: A 46-year-old man suffering from progressive deafness since childhood received a Clarion 90 K cochlear implant with the HiRes preformed electrode in his left ear in October 2006. A persistent Staphylococcus aureus infection failed to be treated with corticoids, amoxicillin/ clavulanate, ciprofloxaxin, and rifampin. The processor was removed on July 2007.
The removed cochlear implant processor was treated with different reagents, with the aim of detecting a S. aureus and S. aureus biofilm: (1) fluorescein-coupled Fc of anti-human serum, (2) polyclonal anti-polysaccharide intercellular adhesion antibodies coupled to Alexa Fluor 568 goat anti-rabbit immunoglobulin (Ig)G, (3) crystal violet, (4) methylene blue, (5) acridine orange, (6) Gram stain, and (7) live/dead fluorescent stain.
S. aureus and the major constituent of the S. aureus biofilm, the polysaccharide intercellular adhesion, were detected on the surface of the implant. S. aureus was isolated after a simple contact between the implant and a solid growth medium. The ability of the isolated S. aureus strain to produce biofilm in vitro was confirmed.
S. aureus biofilm was documented on the implant. Initial bacterial colonization could be related to the pocket of the removable magnet. Colonies of S. aureus without biofilm were found attached to the electrode wire.
We report one case of a S. aureus biofilm infection documented on a cochlear implant, as assessed by immuno-microscopy. The biofilm was likely responsible for the persistent infection which manifested for many months after the implant surgery and could explain the unusual bacterial phenotypic resistance against administered antimicrobial agents.
Infection 04/2009; 37(5):450-4. · 2.66 Impact Factor
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ABSTRACT: This study investigates aspects of the general assumption that, in bacteria, genetic variation in functionally-constrained genomic regions accumulates at a lower rate than in regions of hypermutability such as DNA repeat loci. We compared whole genome polymorphism (using high-throughput amplified fragment length polymorphism [ht-AFLP]) as well as short sequence repeat length variation (using multi-locus variable number of tandem repeat analysis [MLVA]) for 994 Staphylococcus aureus strains isolated from both healthy carriers and invasive infections. MLVA and ht-AFLP minimum spanning trees (MSTs) were similar in their identification of totally different types of genetic variants. This suggests that, despite the enhanced inherent variability of repeats, clusters of strains remain traceable. Finally, no specific molecular marker of epidemicity or virulence was identified in this large strain collection by the MLVA approach. We demonstrate that there is a difference in the rates of cross-genome mutation versus regional repeat variability in the clonal bacterial pathogen S. aureus. Despite these dynamic differences, a conservation of type assignments as based upon these two inherently different typing techniques was observed.
European Journal of Clinical Microbiology 08/2008; 28(1):39-45. · 2.86 Impact Factor
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ABSTRACT: The prevalence of intracellular Staphylococcus aureus organisms in the nasal mucosa of patients with recurrent infectious rhinosinusitis episodes was studied.
Twenty-seven consecutive adult patients who failed medical management of chronic rhinosinusitis (CRS) of multiple origins, associated or not with nasal polyposis, were consecutively enrolled for endonasal sinus surgery (including partial middle turbinectomy, middle antrostomy, ethmoidectomy, sphenoidotomy) and followed for a 12-month post-operative period.
Seventeen of these patients showed the presence of intracellular S. aureus as detected by confocal laser scan immunofluorescence microscopy in epithelial cells of surgical intranasal biopsy specimens. Nine of the patients with and two without intracellular bacteria yielded S. aureus in endoscopically guided cultures of middle meatus secretions, despite the recent administration of prophylactic antibiotics. Eleven of the 17 patients with intracellular S. aureus relapsed for rhinosinusitis within the 12-month follow-up period. Molecular typing of sequential S. aureus isolates demonstrated the persistence of unique patient-specific S. aureus clonotypes in nine of the patients with intracellular bacteria during the 12-month follow-up.
The presence of intracellular S. aureus in epithelial cells of the nasal mucosa is a significant risk factor for recurrent episodes of rhinosinusitis due to persistent bacterial clonotypes, which appear refractory to antimicrobial and surgical therapy.
Rhinology 01/2007; 44(4):249-54. · 1.32 Impact Factor
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ABSTRACT: Diamond-like carbon (DLC) and silicon carbide (SiC) coatings are attractive because of low friction coefficient, high hardness, chemical inertness and smooth finish, which they provide to biomedical devices. Silicon wafers (Si(waf)) and silicone rubber (Si(rub)) plates were coated using plasma-enhanced chemical vapour deposition (PE-CVD) techniques. This article describes: 1- the characterization of modified surfaces using attenuated total reflection-Fourier transform infrared spectroscopy (ATR/FTIR) and contact angle measurements, 2- the results of three in-vitro haemocompatibility assays. Coated surfaces were compared to uncoated materials and various substrates such as polymethylmethacrylate (PMMA), polyethylene (LDPE), polydimethylsiloxane (PDMS) and medical steel (MS). Thrombin generation, blood platelet adhesion and complement convertase activity tests revealed the following classification, from the most to the least heamocompatible surface: Si(rub)/ DLC-Si(rub)/ DLC-Si(waf)/ LDPE/ PDMS/ SiC-Si(waf)/ Si(waf)/ PMMA/ MS. The DLC coating surfaces delayed the clotting time, tended to inhibit the platelet and complement convertase activation, whereas SiC-coated silicon wafer can be considered as thrombogenic. This study has taken into account three events of the blood activation: coagulation, platelet activation and inflammation. The response to those events is an indicator of the in vitro haemocompatibility of the different surfaces and it allows us to select biomaterials for further in vivo blood contacting investigations.
European cells & materials 07/2003; 5:17-26; discussion 26-8. · 3.03 Impact Factor
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ABSTRACT: Since Staphylococcus aureus expresses multiple pathogenic factors, studying their individual roles in single-gene-knockout mutants is difficult. To circumvent this problem, S. aureus clumping factor A (clfA) and fibronectin-binding protein A (fnbA) genes were constitutively expressed in poorly pathogenic Lactococcus lactis using the recently described pOri23 vector. The recombinant organisms were tested in vitro for their adherence to immobilized fibrinogen and fibronectin and in vivo for their ability to infect rats with catheter-induced aortic vegetations. In vitro, both clfA and fnbA increased the adherence of lactococci to their specific ligands to a similar extent as the S. aureus gene donor. In vivo, the minimum inoculum size producing endocarditis in > or =80% of the rats (80% infective dose [ID80]) with the parent lactococcus was > or =10(7) CFU. In contrast, clfA-expressing and fnbA-expressing lactococci required only 10(5) CFU to infect the majority of the animals (P < 0.00005). This was comparable to the infectivities of classical endocarditis pathogens such as S. aureus and streptococci (ID80 = 10(4) to 10(5) CFU) in this model. The results confirmed the role of clfA in endovascular infection, but with a much higher degree of confidence than with single-gene-inactivated staphylococci. Moreover, they identified fnbA as a critical virulence factor of equivalent importance. This was in contrast to previous studies that produced controversial results regarding this very determinant. Taken together, the present observations suggest that if antiadhesin therapy were to be developed, at least both of the clfA and fnbA products should be blocked for the therapy to be effective.
Infection and Immunity 10/2001; 69(10):6296-302. · 4.16 Impact Factor
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Current clinical topics in infectious diseases 02/2001; 21:252-70.
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ABSTRACT: Foreign body implants are highly susceptible to microorganism infection. The infectious agents may be of low pathogenicity (such as S. epidermidis) or involve more virulent strains (such as S. aureus). The common denominator for the three main elements that play a role in the physiopathology of such infections (bacteria, neutrophils, and different biomaterials) are host proteins deposited over the surface of the devices immediately after their implantation. These proteins modulate that host cells response but can also promote Staphylococcus adhesion to the biomaterial. Neutrophils and other cells such as fibroblasts adhere to several extracellular matrix proteins such as fibronectin, fibrinogen, collagen, vitronectin, via specific cell surface receptor. The evolution of the technology and the increasing numbers of long-term artificial implants require a better understanding of fundamental mechanisms of foreign body infections to reduce their incidence and optimize their treatment.
Annals of Vascular Surgery 02/1998; 12(1):34-40. · 1.03 Impact Factor
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ABSTRACT: We present an investigation of the physico-chemical surface properties of commercially pure titanium coverslips which were submitted to various treatments designed to optimize their topography in view of application in oral implantology. The surface microroughness, chemical composition and water wettability were analyzed on titanium coverslips prepared by mechanical polishing, acid attack in HCl/H2SO4, after mechanical polishing or sandblasting, and titanium plasma-spray. The chemical composition has been measured by Auger electron spectroscopy. The treatments have no major influence on the surface chemical composition and all the samples display a composition approaching that of TiO2 with minor amounts of carbon, sulfur, silicon and calcium as impurities. The roughness has been measured by scanning force microscopy on an area of 20 microns x 20 microns on each sample. Polished titanium is smooth (peak-to-valley roughness 81 nm), whereas the acid-attacked surfaces exhibit a micro-roughness in the microns range (2100 nm for polished and acid attacked; 3600 nm for sandblasted and acid attacked) which is quite reproducible over large areas of the sample. The acid attacked samples present a subsurface layer which contains hydrogen below the native passivating oxide layer. Water wettability measurement shows that all surfaces are hydrophobic with a slightly higher contact angle for the acid attacked surfaces. The different treatments analyzed in this study essentially influence the surface roughness by preserving the chemical composition and the wettability properties of titanium native oxide surface layer.
Clinical Oral Implants Research 07/1997; 8(3):208-16. · 2.51 Impact Factor
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ABSTRACT: The influence of titanium surface properties on in vitro adsorption isotherms of fibronectin, promotion of Staphylococcus aureus adhesion, and binding of a monoclonal antibody to the cell-binding domain of fibronectin was examined. Treatments producing different surface roughness were applied to a single side of commercially pure titanium coverslips, which was either mechanically polished (P), or polished and then acid attacked with H2SO4/HCl (PA), or sandblasted and then acid attacked (SLA), whereas the untreated side was blocked by an albumin coating layer. Incubation of the coverslips with concentrations of soluble 3H-labelled fibronectin increasing from 1 to 16 micrograms/ml led to the saturation of all surfaces with immobilized protein from 4 to 16 micrograms/ml. Promotion of S. aureus adhesion by fibronectin adsorbed on all surfaces and binding of the monoclonal antibody to its cell-binding domain was to some extent proportional to the amount of immobilized protein but also showed some minor differences between surfaces. More important material-related differences were observed when fibronectin adsorption isotherms were expressed as a function of the effective, roughness-corrected surface area, yielding amounts of immobilized fibronectin on the rough PA and SLA titanium surfaces which were 50% lower than those adsorbed on either smooth P or polymethylmethacrylate coverslips used as controls. In conclusion, surface treatments increasing the surface roughness of titanium do not increase, but may partly decrease in vitro adsorption of fibronectin. Despite adsorbing different amounts of fibronectin, both rough and smooth titanium surfaces promote normal expression of 2 major functional domains of this protein.
Clinical Oral Implants Research 07/1997; 8(3):217-25. · 2.51 Impact Factor
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ABSTRACT: Persistent staphylococcal infections are a major medical problem, especially when they occur on implanted materials or intravascular catheters. This review describes some of the recently discovered molecular mechanisms of Staphylococcus aureus attachment to host proteins coating biomedical implants. These interactions involve specific surface proteins, called bacterial adhesins, that recognize specific domains of host proteins deposited on indwelling devices, such as fibronectin, fibrinogen, or fibrin. Elucidation of molecular mechanisms of S aureus adhesion to the different host proteins may lead to the development of specific inhibitors blocking attachment of S aureus, which may decrease the risk of bacterial colonization of indwelling devices.
Infection Control and Hospital Epidemiology 09/1996; 17(8):514-20. · 3.67 Impact Factor
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ABSTRACT: The pathogenic role of staphylococcal coagulase and clumping factor was investigated in the rat model of endocarditis. The coagulase-producing and clumping factor-producing parent strain Staphylococcus aureus Newman and a series of mutants defective in either coagulase, clumping factor, or both were tested for their ability (i) to attach in vitro to either rat fibrinogen or platelet-fibrin clots and (ii) to produce endocarditis in rats with catheter-induced aortic vegetations. In vitro, the clumping factor-defective mutants were up to 100 times less able than the wild type strain to attach to fibrinogen and also significantly less adherent than the parents to platelet-fibrin clots. Coagulase-defective mutants, in contrast, were not altered in their in vitro adherence phenotype. The rate of in vivo infection was inoculum dependent. Clumping factor-defective mutants produced ca. 50% less endocarditis than the parent organisms when injected at inoculum sizes infecting, respectively, 40 and 80% (ID40 and ID80, respectively) of rats with the wild-type strain. This was a trend at the ID40 but was statistically significant at the ID80 (P < 0.05). Coagulase-defective bacteria were not affected in their infectivity. Complementation of a clumping factor-defective mutant with a copy of the wild-type clumping factor gene restored both its in vitro adherence and its in vivo infectivity. These results show that clumping factor plays a specific role in the pathogenesis of S. aureus endocarditis. Nevertheless, the rate of endocarditis with clumping factor-defective mutants increased with larger inocula, indicating the contribution of additional pathogenic determinants in the infective process.
Infection and Immunity 01/1996; 63(12):4738-43. · 4.16 Impact Factor
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ABSTRACT: We used an ex vivo canine arteriovenous shunt model, previously developed to study plasma protein adsorption and thrombogenesis on polymeric biomaterials, to define the role of host proteins in promoting adhesion of Staphylococcus aureus. Either polyethylene or polyvinyl chloride tubings were exposed to canine blood for 5, 15, or 60 min at a flow rate of 300 ml/min and then were flushed in phosphate-buffered saline (PBS), cut into 1.5-cm segments, and stored at -70 degrees C. After thawing, each segment was preincubated in 0.5% albumin in PBS to prevent nonspecific staphylococcal attachment to surfaces that were not exposed to blood. Each segment was then incubated with 4 x 10(6) CFU of [3H]thymidine-labelled S. aureus per ml for 60 min at 37 degrees C in an in vitro adhesion assay. Two site-specific mutants of S. aureus were tested: one specifically defective in adhesion to surface-bound fibronectin (FnAd-def) and the other defective in adhesion to fibrinogen (FgAD-def) [corrected]. Compared with their respective parental strains, the FgAd-def, but not the FnAd-def, mutant of S. aureus showed a strong (> 80%) decrease in attachment to ex vivo tubings. The adhesion of each strain of S. aureus onto polyethylene was consistently more than twofold higher than the adhesion onto polyvinyl chloride segments exposed to flowing blood for 5 or 15 min, but adhesion became similar to that on polyvinyl chloride after 60 min of exposure. In conclusion, the specific adhesion-defective mutants of S. aureus suggested that fibrinogen was the most active adhesion-promoting protein in a short-term blood-material interaction. The experimental approach described in this study should prove useful for screening materials thought to be resistant to protein-mediated staphylococcal adhesion and colonization.
Infection and Immunity 03/1995; 63(2):585-90. · 4.16 Impact Factor
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ABSTRACT: Biomer is a poly(ether-urethane-urea) block copolymer widely used as biomedical devices. Extraction process of this polymer has purified its surface of low molecular weight polyurethane chains and Santowhite Powder additive. ESCA and ATR/FTIR have suggested a homogenization of the polymer by enrichment of the first layers with poly(aminomethacrylate) additive after extraction. Therefore, the surface of the extracted Biomer exhibits a different wettability and biological response. The treatment causes a significant decrease in fibronectin adsorption and induces a reduction in Staphylococcus aureus adhesion.
Journal of Biomaterials Science Polymer Edition 02/1995; 7(1):49-60. · 1.69 Impact Factor
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ABSTRACT: Objective: Group B Streptococcus (GBS) and Escherichiacoli(E. coli) are the leading causes of early-onset neonatal disease (EOD). Intrapartum antibiotic prophylaxis of GBS-colonized women decreases vertical transmission and EOD due to GBS. Nevertheless, no intervention has been developed to reduce the risk of EOD related to E. coli. Timely and accurate identification of colonized mothers is necessary to implement preventive strategies against neonatal sepsis. To screen for colonization during labor, we developed a real-time PCR assay for the simultaneous detection of GBS and neonatal invasive strains of E. coli. Study Design: Specific DNA targets for GBS are publicly available. For neonatal invasive E. coli, we analyzed candidate DNA targets by DNA hybridization on microarrays of invasive strains isolated from neonatal E. coli sepsis or meningitis (K1 and not K1 ‘invasive’ serotypes). Specificity of DNA probes was tested against a panel of bacteria and by simulating clinical conditions (spiking vaginal samples from pregnant women). Then, the characteristics of the selected probes were evaluated in a pilot study including 200 women in labor. Results: Prevalence of rectovaginal GBS and of vaginal and cervical E. coliserotype K1 colonization were 16.0, 3.5 and 3.5% by culture and 27, 10 and 8.5% by PCR, respectively. The prevalence of other invasive E. coli in the vagina and in the cervix, detected by PCR, was around 10%. Compared to the culture, considered as the gold standard, the sensitivities of the PCRs for the GBS and E. coli K1 were 97 and 71%, respectively. Specificities were 86 and 92%, respectively. Specificity is difficult to interpret, as a false-positive PCR result may in fact be a false-negative result of the culture. The turnaround time needed for PCR analysis was 2.5 h, compared to a minimum of 48 h for the culture. Conclusion: Our rapid PCR is reliable in detecting GBS in women in labor. Optimization of the PCR for invasive E. coli is needed before its implementation in clinical practice. More efforts to fight against main causes of neonatal sepsis need to be undertaken to prevent this terrible medical complication.
Gynecologic and Obstetric Investigation 08/1970; 70(4):250-255. · 1.28 Impact Factor
