Gardnerella vaginalis ventilatory acquired pneumonia among patients with trauma.

Gardnerella vaginalis (G. vaginalis) is a bacterium rarely responsible for systemic infections and is exceptionally isolated from bronchopulmonary samples. Here, we report here two patients with trauma who were diagnosed with a G. vaginalis ventilatory acquired pneumonia (VAP) via mini bronchoalveolar lavage (mini-BAL). According to our observations, G. vaginalis was the only microorganism with a significant threshold and the identification was obtained by a reliable mean. There is no recommendation for antibiotic treatment for invasive G. vaginalis infection. We treated these infections with Cefotaxim and Metronidazole which clinically improved the infection. To determine whether the two patients were infected by the same strain, we used a random amplified polymorphic DNA (RAPD) technique. The two G. vaginalis organisms had distinct RAPD profiles, suggesting the absence of cross-transmission. These two cases of trauma and G. vaginalis VAP suggest that this infection cannot be ruled out and should alert the clinician to treat it.

Early switching from intravenous to oral antibiotic therapy in bone and joint infections associated with methicillin-susceptible Staphylococcus aureus bacteremia.

OBJECTIVES: We aimed to evaluate the clinical outcomes of patients with bone and joint infection (BJI) associated with methicillin-susceptible Staphylococcus aureus bacteremia (MSSAB) treated with early oral switch to oral antibiotics (before day 14) versus later or no switch. PATIENTS AND METHODS: We included all cases reported between January 2016 and December 2021 in the University Hospital of Reims. RESULTS: Among 79 patients with BJI associated with MSSAB, 50.6% had an early switch to oral antibiotics, with median duration of intravenous antibiotics of 9 (IQR 6-11) days. The overall cure rate was 81% with follow-up of 6 months, and was 85.7% after excluding the 9 patients whose death was not related to BJI infection. Failure to control BJI did not differ between the two groups. CONCLUSION: An early (before day 14) switch to oral antibiotics may be a safe therapeutic option in BJI associated with MSSAB.

Evolution of antibiotic treatments for healthcare-associated infections caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae in France.

BACKGROUND: Infections caused by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLE) remain a public health challenge. AIM: We traced the evolution of antibiotics prescribed for patients with ESBLE-healthcare associated infections (ESBLE-HAI) between 2012 and 2017, with a specific focus on treatments for lower urinary tract infections (LUTI). METHODS: We used the 2012 and 2017 French point prevalence survey data. Patients with ESBLE-HAI were defined as those diagnosed with at least one Enterobacteriaceae with ESBL production. Patients with LUTI caused by ESBLE (ESBLE-LUTI) were defined as those with LUTI as the reported infection site and diagnosed with ESBLE. We only analysed treatments intended for HAI. RESULTS: In 2017, more than half of treatments for ESBLE-HAIs were ß-lactams. While from 2012 to 2017 the proportion of carbapenem treatments decreased from 30% to 25%, penicillin treatments doubled. Among patients treated for ESBLE-LUTI, a larger proportion received a single antibiotic in 2017. The most frequently prescribed antibiotics for these infections were amoxicillin/clavulanic acid, nitrofurantoin and ofloxacin. More than one out of six treatments lasted for more than 7 days. Carbapenem use was halved between 2012 and 2017, and decreases were likewise observed for aminoglycosides. CONCLUSION: In accordance with French recommendations, comparison of the two most recent French point prevalence surveys showed an evolution in ESBLE-HAI treatment, especially for ESBLE-LUTI. However, treatment durations remained longer than recommended. Data from the 2022 survey should provide insights on the future evolution of prescription trends.

Surfaces and Air Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 Using High-Flow Nasal Oxygenation or Assisted Mechanical Ventilation in Intensive Care Unit Rooms of Patients With Coronavirus Disease 2019.

BACKGROUND: Understanding patterns of environmental contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for infection prevention policies. METHODS: We screened surfaces and air samples from single-bed intensive-care unit rooms of adult patients with coronavirus disease 2019 (COVID-19) for SARS-CoV-2 RNA and viable viruses. RESULTS: We evidenced viral RNA environmental contamination in 76% of 100 surfaces samples and in 30% of 40 air samples without any viable virus detection by cell culture assays. No significant differences of viral RNA levels on surfaces and in ambient air were observed between rooms of patients with assisted mechanical ventilation and those of patients with a high-flow nasal cannula system. Using an original experimental SARS-CoV-2 infection model of surfaces, we determined that infectious viruses may have been present on benches within 15 hours before the time of sampling in patient rooms. CONCLUSIONS: We observed that SARS-CoV-2 environmental contamination around patients with COVID-19 hospitalized in single-bed ICU rooms was extensive and that a high-flow nasal cannula system did not generate more viral aerosolization than a mechanical ventilation system in patients with COVID-19. Despite an absence of SARS-CoV-2 viable particles in study samples, our experimental model confirmed the need to apply strict environmental disinfection procedures and classic standard and droplet precautions in ICU wards.

Bone and joint infections caused by Clostridium perfringens: a case series.

The objective of this study was to evaluate antimicrobial therapy outcomes of bone and joint infections (BJI) caused by Clostridium perfringens. We investigated remission of symptoms and the absence of relapse or reinfection during follow-up. Among the 8 patients with C. perfringens BJI, the type of infection was early prosthesis infection (n = 2), osteosynthetic device infection (n = 4), and chronic osteomyeletis (n = 2). Clindamycin-rifampicin combination was given in 4 cases and metronidazole in 4 cases. The overall success rate was 87.5%. Among the 7 patients who completed antibiotic treatment, the success rate was 100%. The clindamycin-rifampicin combination appeared to be effective in patients with C. perfringens BJI.

Clindamycin combination treatment for the treatment of bone and joint infections caused by clindamycin-susceptible, erythromycin-resistant Staphylococcus spp.

The objective of this study was to evaluate the clinical outcomes and safety of clindamycin combination antibiotherapy for the treatment of erythromycin-resistant, lincosamide-susceptible bone and joint infections caused by Staphylococcus spp. Between January 2010 and September 2018, 46 patients with Staphylococcus spp. erythromycin-resistant, lincosamide-susceptible bone and joint infections were treated with clindamycin combination antibiotherapy for 6 to 12 weeks. The type of infection was prosthetic in 20 cases (43.5%), osteosynthetic device in 15 cases (32.6%), chronic osteomyelitis in 7 cases (15.2%), and arthritis in 4 cases (8.7%). The cure rate was 67.4% by intention to treat and 84.6% per protocol, with a median follow-up of 398 days (range 86-843). Only 2 relapses (5.1%) were observed in patients with chronic osteomyelitis; an acquired resistance to lincosamides developed in 1 case. Clindamycin combination therapy appears to be effective for the treatment of bone and joint infection caused by erythromycin-resistant, lincosamide-susceptible Staphylococcus spp.

Obesity and Preoperative Anaemia as Independent Risk Factors for Sternal Wound Infection After Coronary Artery Bypass Graft Surgery with Pedicled (Non-Skeletonized) Internal Mammary Arteries: The Role of Thoracic Wall Ischemia?

PURPOSE: Obesity remains statistically associated with coronary artery disease, for which coronary artery bypass graft surgery (CABG) remains the standard of care. However, obesity is also associated with sternal wound infection (SWI) which is a severe complication of CABG despite advances in surgery and in infection prevention and control. Strategies to reduce the incidence of SWI are still being investigated, and we therefore conducted a retrospective study to revisit factors other than obesity associated with SWI after CABG. PATIENTS AND METHODS: Data were extracted from the medical records of 182 patients who underwent elective on-pump CABG using one or both pedicled internal mammary artery grafts in Reims University Hospital between May 2015 and May 2016. All preoperative or perioperative variables with a p value<0.10 in univariate analysis were entered into a stepwise logistic regression model. RESULTS: Among the 182 patients (145 male (79.6%), median age 68.0 [45.0-87.0] years), 138 (75.8%) underwent CABG using bilateral internal mammary artery grafts. Median BMI was 27.7 [18.7-50.5] kg/m2, and there were 51 (28.0%) and 79 (43.4%) patients with obesity and overweight, respectively. Twenty-three out of the 182 patients (12.6%) developed SWI. In-hospital mortality was not statistically different between patients with and without SWI but the median length of stay was (6.0 [2.0-38.0] versus 5.0[3.0-21.0] days in the intensive care unit, p=0.03, and 26.0 [9.0-134.0] versus 9.0 [7.0-51.0] days in hospital, p<0.0001). Obesity and preoperative anaemia were independently associated with SWI, as was the number of red blood cell (RBC) units transfused (OR 14.61 [2.64-80.75], OR 4.64 [1.61-13.34] and OR 1.27 [1.02-1.58], respectively). CONCLUSION: The independent association of SWI with the number of RBC units transfused and the existence of preoperative anaemia and obesity suggests a mechanism of thoracic wall ischemia in SWI after CABG, thus leaving insufficient perfusion of the thoracic wall in patients with obesity. Medical strategies are warranted to try to prevent this costly complication.

Phenotypic and genotypic quinolone resistance in Escherichia coli underlining GyrA83/87 mutations as a target to detect ciprofloxacin resistance.

BACKGROUND: Quinolone resistance (QR) is one component of the MDR emerging in Escherichia coli and is of particular concern given the widespread use of fluoroquinolones. OBJECTIVES: To characterize the QR phenotypes and genotypes in E. coli responsible for bloodstream infections and to propose molecular determinants that could be targeted to predict ciprofloxacin resistance. METHODS: E. coli isolates from blood cultures in three French hospitals were studied for quinolone MICs and characterization of genotypic QR determinants (QRg). RESULTS: Among 507 isolates tested for MICs, 148 (29.2%) were resistant to quinolones based on EUCAST breakpoints and 143 (28.2%) harboured at least one QRg. QRg were mainly mutations in the QRDR (138 isolates, 27.2%), with 55.8% of these isolates carrying at least three QRDR mutations. gyrA mutations predominated (92.8%) followed by parC (61.6%), parE (32.6%) and gyrB (1.4%) mutations. Only 4.7% of the isolates harboured a plasmid-mediated quinolone resistance (PMQR) gene: aac(6')-Ib-cr (60.0%) or qnr (qnrS, qnrB) (32.0%). For the first time in France, we reported the qepA4 allele of the plasmid-encoded efflux pump QepA. Only five isolates carried PMQR without a QRDR mutation. The positive predictive value (PPV) for ciprofloxacin resistance was 100% for any QRg and 99.2% for gyrA mutations specifically. CONCLUSIONS: QR observed in E. coli isolates involved in bloodstream infections is still mainly due to QRDR mutations, especially at codons GyrA83/87, which could be used as a molecular target to rapidly detect resistance.

Treatment of bone and joint infections caused by Enterobacter cloacae with a fluoroquinolone-cotrimoxazole combination.

Although the frequency of bone and joint infections caused by Enterobacter spp. is increasing, studies regarding the optimal antibiotic therapy are scarce. The objective of this retrospective study was to assess the clinical outcomes and safety of a fluoroquinolone-cotrimoxazole combination for the treatment of bone and joint infections caused by Enterobacter cloacae. Between 2010 and 2017, 30 patients with bone and joint infections caused by E. cloacae were treated with a fluoroquinolone-cotrimoxazole combination for 8-12 weeks. There were 26 cases (87%) of infection of an internal fixation device, two cases (6.6%) of pseudarthrosis with chronic osteomyelitis, and two cases (6.6%) of infection of knee and ankle prosthetic devices. The cure rate of the fluoroquinolone-cotrimoxazole combination was 80% by intention-to-treat analysis, with a mean follow-up of 29.3 ± 19.1 months. The fluoroquinolone-cotrimoxazole combination for 8-12 weeks is effective for the treatment of bone and joint infections caused by E. cloacae.

Management of septic non-union of the tibia by the induced membrane technique. What factors could improve results?

INTRODUCTION: Management of septic non-union of the tibia requires debridement and excision of all infected bone and soft tissues. Various surgical techniques have been described to fill the bone defect. The "Induced Membrane" technique, described by A. C. Masquelet in 1986, is a two-step procedure using a PMMA cement spacer around which an induced membrane develops, to be used in the second step as a bone graft holder for the bone graft. The purpose of this study was to assess our clinical and radiological results with this technique in a series managed in our department. MATERIAL AND METHOD: Nineteen traumatic septic non-unions of the tibia were included in a retrospective single-center study between November 2007 and November 2014. All patients were followed up clinically and radiologically to assess bone union time. Multivariate analysis was used to identify factors influencing union. RESULTS: The series comprised 4 women and 14 men (19 legs); mean age was 53.9 years. Vascularized flap transfer was required in 26% of cases before the first stage of treatment. All patients underwent a two-step procedure, with a mean interval of 7.9 weeks. Mean bone defect after the first step was 52.4mm. The bone graft was harvested from the iliac crest in the majority of cases (18/19). The bone was stabilized with an external fixator, locking plate or plaster cast after the second step. Mean follow-up was 34 months. Bony union rate was 89% (17/19), at a mean 16 months after step 2. Eleven patients underwent one or more (mean 2.1) complementary procedures. Severity of index fracture skin opening was significantly correlated with union time (Gustilo III vs. Gustilo I or II, p=0.028). A trend was found for negative impact of smoking on union (p=0.06). Bone defect size did not correlate with union rate or time. DISCUSSION: The union rate was acceptable, at 89%, but with longer union time than reported in the literature. Many factors could explain this: lack of rigid fixation after step 2 (in case of plaster cast or external fixator), or failure to cease smoking. The results showed that the induced membrane technique is effective in treating tibial septic non-union, but could be improved by stable fixation after the second step and by cessation of smoking. LEVEL OF EVIDENCE: IV, Retrospective study.

Spread of Klebsiella pneumoniae ST395 non-susceptible to carbapenems and resistant to fluoroquinolones in North-Eastern France.

OBJECTIVES: Fluoroquinolones (FQs) are a potential treatment for infections caused by extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae that are susceptible to these agents. METHODS: Owing to increasing non-susceptibility to carbapenems among Enterobacteriaceae, in this study FQ resistance mechanisms were characterised in 36 ertapenem-non-susceptible Klebsiella pneumoniae isolated from North-Eastern France in 2012. The population structure was described by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). RESULTS: Among the 36 isolates, 13 (36%) carried a carbapenemase encoding-gene. Decreased expression of the OmpK35-encoding gene might be considered a major resistance determinant that could explain the non-susceptibility to carbapenems. The carbapenemase-producing isolates carried the well-known IncL pOXA-48a plasmid. All 36 K. pneumoniae isolates also harboured a FQ resistance determinant. The aac(6')-Ib-cr gene was the major plasmid-mediated quinolone resistance (PMQR) determinant found in K. pneumoniae (89%; 32/36). MLST identified five sequence types (STs), with the most common being ST395 (69%; 25/36), followed by ST147 (17%; 6/36). ST395 strains showed ertapenem minimum inhibitory concentrations (MICs) ranging from 0.75-32µg/mL. Klebsiella pneumoniae ST395 isolates did not show enhanced biofilm formation or environmental survival but showed higher chlorhexidine MICs compared with ST147 isolates. CONCLUSIONS: These findings showed that (i) K. pneumoniae ST395 carrying pOXA-48a has spread in North-Eastern France, (ii) aac(6')-Ib-cr is predominant in carbapenem-non-susceptible K. pneumoniae, (iii) K. pneumoniae ST395 is resistant to chlorhexidine and (iv) FQs as an alternative to ß-lactams to treat ertapenem-non-susceptible K. pneumoniae are compromised.

Factors associated with carriage of carbapenem-non-susceptible Enterobacteriaceaein North-Eastern France and outcomes of infected patients.

Background: Carbapenems are frequently used as a last resort to treat infections caused by multidrug-resistant Gram-negative organisms, thus carbapenem-non-susceptible Enterobacteriaceae (CNSE) is an emerging health threat. Objectives: To assess risk factors and outcomes of CNSE carriage. Patients and methods: We conducted a matched case-control study in six hospitals in North-Eastern France. The controls were patients harbouring carbapenem-susceptible Enterobacteriaceae. Fifty-five cases and 110 controls were included. Results: Most of the CNSE isolates were Enterobacter cloacae and Klebsiella pneumoniae . Carbapenemase production was observed in 40% of isolates and they produced OXA-48 only. CNSE carriage was significantly associated with recent antibiotic use ( P = 0.014), particularly carbapenems ( P = 0.03) and fluoroquinolones ( P = 0.016). A multivariate analysis using conditional logistic regression showed that the presence of concomitant infection(s) (OR: 9.83; 95% CI 3.04-21.39, P = 0.0031), nosocomial infections (OR: 7.84; 95% CI 2.00-12.54, P = 0.0063) and a high age (OR: 1.07; 95% CI 1.01-1.06, P = 0.038) were independently associated with CNSE carriage. Moreover, patients infected with CNSE had worse outcomes: fewer resolved infections at 1 month ( P = 0.02), and they had a higher mortality rate ( P = 0.0004) and longer hospital stays ( P = 0.02). Conclusions: We identified three independent risk factors for CNSE carriage as well as worse outcomes in infected patients in North-Eastern France. This highlights the importance of early detection of CNSE and the need for antimicrobial therapy re-evaluation after bacteriological analysis has been performed.

Fluoroquinolone Resistance Mechanisms and population structure of Enterobacter cloacae non-susceptible to Ertapenem in North-Eastern France.

Fluoroquinolone (FQ) agents are a potential resort to treat infection due to Enterobacteriaceae producing extended spectrum ß-lactamase and susceptible to FQ. In a context of increase of non-susceptibility to carbapenems among Enterobacteriaceae, we characterized FQ resistance mechanisms in 75 Enterobacter cloacae isolates non-susceptible to ertapenem in North-Eastern France in 2012 and describe the population structure by pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Among them, 14.7% (12/75) carried a carbapenemase-encoding gene. Except one isolate producing VIM-1, the carbapenemase-producing isolates carried the well-known IncL/M pOXA48a plasmid. Most of the isolates (59/75) harbored at least a FQ-R determinant. qnr genes were predominant (40%, 30/75). The MLST study revealed that E. cloacae isolates' clonality was wide [24 different sequence types (STs)]. The more widespread STs were ST74, ST101, ST110, ST114, and ST133. Carbapenem MICs were higher for E. cloacae ST74 than for other E. cloacae isolates. Plasmid-mediated quinolone resistance determinants were more often observed in E. cloacae ST74 isolates. These findings showed that (i) pOXA-48a is spreading in North-Eastern France, (ii) qnr is preponderant in E. cloacae, (iii) E. cloacae comprised a large amount of lineages spreading in North-Eastern France, and (iv) FQ as an alternative to ß-lactams to treat ertapenem non-susceptible Enterobacteriaceae are compromised.

Infections in Total Hip and Total Knee Arthroplasty: Development of a Score To Assess Endogenous Risk of Surgical Site Infections.

BACKGROUND: Surgical site infections (SSI) are a dreaded complication of total hip (THA) and knee arthroplasties (TKA), and are a major public health concern. Risk factors are well known, but no endogenous risk assessment score exists. The objective of this study to develop a score to assess endogenous risk of infection after THA or TKA. METHODS: All infections after TKA and THA implanted in the department of orthopedic surgery of a teaching hospital between January 2007 and December 2012 were included. Two control groups were matched to cases on the type of prosthesis (hip or knee; first-line or revision). RESULTS: Twenty-four SSIs after THA and 21 after TKA were registered (respective incidence during the study period: 1.56 and 1.91%). Relevant endogenous risk factors found were: Smoking (adjusted odds ratio=3.9), a BMI greater than 35 kg/mÇ (1.8), inflammatory rheumatism (7.3), and the number of operations (prosthetic or not) on the involved joint (2.9 per additional surgery). The average score of endogenous infection risk on all analyzed subjects was 3.37±3.33 (median=3, range=0-17). Mean scores were substantially different among cases and control groups: Respectively 5.84±4.04 vs 2.13±2.01 (p<0.0001). With a five-point threshold, the sensitivity and specificity of the score are respectively 62 and 91%. ASA score greater than or equal to three was not found to be substantial risk factor in this study (p=0.15). CONCLUSIONS: Endogenous infection risk score studied here was found to be relevant in discriminating cases from control groups, but requires validation in a larger cohort.

aac(6')-Ib-cr is the major plasmid-mediated quinolone resistance determinant in extended-spectrum ß-lactamase-producing Escherichia coli in eastern France.

The aim of this study was to describe the presence of plasmid-mediated quinolone resistance (PMQR) determinants in extended spectrum ß-lactamase-producing Escherichia coli (ESBL-Ec) in hospitals in eastern France. All ESBL-Ec isolated from May 2008 to April 2009 in nine hospitals in eastern France were collected and screened by PCR for the presence of PMQR genes. bla genes were identified by PCR and sequencing. Randomly chosen PMQR-positive ESBL-Ec isolates were characterised by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and phylogenetic group identification. Of the 447 ESBL-Ec tested, 122 (27.3%) had a PMQR determinant. aac(6')-Ib-cr was more prevalent (118/122; 96.7%) than qnr [4/122 (3.3%), comprising 2 qnrB2, 1 qnrB1 and 1 qnrA1]. Among 37 PMQR-positive ESBL-Ec isolates selected for typing, 26 (70%) carried blaCTX-M-15 of which 25/26 (96%) co-harboured aac(6')-Ib-cr. Of the 37 isolates, 14 belonged to the B2:ST131 clone, all of which produced AAC(6')-Ib-cr. On the other hand, most of the qnr genes (3/4) were observed in strains carrying bla genes other than blaCTX-M (qnrB2 and blaSHV-12; qnrA1 and blaTEM-52). These findings suggest that aac(6')-Ib-cr, rather than qnr, is the spreading PMQR determinant in ESBL-Ec isolates, and the qnr determinant is not specifically associated with blaCTX-M genes in France. aac(6')-Ib-cr was the predominant PMQR gene in ESBL-Ec isolated in eastern France hospitals, suggesting that the distribution may be due to clonal spread of ST131 CTX-M-15-producing E. coli isolates.

National multidrug-resistant bacteria (MDRB) surveillance in France through the RAISIN network: a 9 year experience.

BACKGROUND: In the mid-1990s, the prevalence rate of multidrug-resistant bacteria (MDRB) in French hospitals was high and control of MDRB spread then became a major priority in the national infection control programme (ICP). METHODS: To evaluate the impact of the ICP, a national coordination of MDRB surveillance was set up in 2002. Data were collected 3 months a year in healthcare facilities (HCFs) on a voluntary basis. All clinical specimens of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBLE) were prospectively included. Incidences per 1000 patient days (PDs) were calculated and trends in incidence from 2003 to 2010 were assessed. RESULTS: Participation in the surveillance increased from 478 HCFs in 2002 to 933 in 2010. In 2010, MRSA incidence was 0.40/1000 PDs: 1.14 in intensive care units (ICUs), 0.48 in acute care facilities (ACFs) and 0.27 in rehabilitation and long-term care facilities (RLTCFs). ESBLE incidence was 0.39/1000 PDs: 1.63 in ICUs, 0.46 in ACFs and 0.23 in RLTCFs. MRSA incidence significantly decreased from 0.72/1000 PDs in 2003 to 0.41/1000 PDs in 2010 (P<10(-3)); in contrast, ESBLE incidence significantly increased from 0.17/1000 PDs to 0.48/1000 PDs (P<10(-3)). The most prevalent ESBLE were Enterobacter aerogenes (34%) and Escherichia coli (25%) in 2003 and E. coli (60%) and Klebsiella pneumoniae (18%) in 2010. CONCLUSION: These results demonstrate the positive impact of the national ICP on MRSA rates. In contrast, ESBLE incidence, especially ESBL-producing E. coli, is increasing dramatically and represents a serious threat for hospitals and for the community that deserves specific control actions.

Description of a 2,683-base-pair plasmid containing qnrD in two Providencia rettgeri isolates.

qnr genes are plasmid-mediated quinolone resistance genes mainly harbored on large conjugative multiresistant plasmids. The qnrD gene was recently observed in Salmonella enterica on a small nonconjugative plasmid (p2007057). We describe two strains of Providencia rettgeri harboring qnrD on nonconjugative plasmids. The plasmids were 99% identical, with 2,683 bp and four open reading frames, including qnrD, but exhibited only 53% identity with the plasmid found in S. enterica.

Feasibility of nasal epithelial brushing for the study of airway epithelial functions in CF infants.

BACKGROUND: For a better understanding of the early stages of cystic fibrosis (CF), it is of major interest to study respiratory epithelial cells obtained as early as possible. Although bronchoalveolar lavage has been proposed for this purpose, nasal brushing, which is a much less invasive technique, has seldom been used in CF infants. The aim of the present study was to examine in a few infants the feasibility of a nasal brushing technique for studies of airway epithelial functions in very young CF infants. METHODS: In 5 CF (median age 12, range 1-18 months) and 10 control infants (median age 5, range 1-17 months), a nasal brushing was performed by means of a soft sterile cytology brush, after premedication with oral paracetamol (15 mg/kg body weight) and rectal midazolam (0.2 mg/kg body weight). Samples were used for microbiological, cytological and functional studies. RESULTS: The procedure was well tolerated. Number of cells collected was similar in CF and non-CF patients (CF: median 230x10(3), range 42x10(3)-900x10(3); non-CF: median 340x10(3), range 140x10(3)-900x10(3)). Median number of viable cells was 67% (range 31-84%). Freshly obtained samples were successfully used for studies of ciliary beating frequency and cAMP-dependent chloride efflux. In 7 out of 17 cell cultures, confluence was obtained (CF: 2 out of 7; non-CF: 5 out of 10). The feasibility of studying protein release and mRNA expression of IL-8, IL-6 and TNF-alpha, under basal conditions and after stimulation by Pseudomonas aeruginosa, was demonstrated. CONCLUSIONS: By means of a simple nasal brushing technique easily performed and well tolerated, it is feasible, in infants, to harvest respiratory cells in sufficient amounts to study the airway epithelium using a broad range of techniques including cell culture.

Pseudomonas aeruginosa may accumulate drug resistance mechanisms without losing its ability to cause bloodstream infections.

In this study, we systematically investigated the resistance mechanisms to beta-lactams, aminoglycosides, and fluoroquinolones of 120 bacteremic strains of Pseudomonas aeruginosa. Pulsed-field gel electrophoresis genotyping showed that 97 of these strains were represented by a single isolate, 10 by 2 and 1 by 3 clonally related isolates, respectively. Seventy-five percent (90 out of 120) of the bacteremic P. aeruginosa strains displayed a significant resistance to one or more of the tested antimicrobials (up to 11 for 1 strain). These strains were found to harbor a great diversity of resistance mechanisms (up to 7 in 1 strain), leading to various levels of drug resistance. Interestingly, 11 and 36% of the isolates appeared to overproduce the MexAB-OprM and MexXY-OprM efflux systems, respectively. Altogether, our results show that P. aeruginosa may accumulate intrinsic (overproduction of cephalosporinase AmpC, increased drug efflux, fluoroquinolone target mutations, and deficient production of porin OprD) and exogenous (production of secondary beta-lactamases and aminoglycoside-modifying enzymes) resistance mechanisms without losing its ability to generate severe bloodstream infections. Consequently, clinicians should be aware that multidrug-resistant P. aeruginosa may remain fully pathogenic.