Native bone and joint infections caused by extended-spectrum ß-lactamase-producing Enterobacterales: experience of a reference centre in the Greater Paris area.

Antibiotic treatment of native osteomyelitis caused by extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-PE) is a challenge. Limited epidemiological and outcome data are available. This retrospective cohort study included osteomyelitis patients with ESBL-PE infections treated in a reference centre for bone and joint infections (BJIs) between 2011-2019. Twenty-nine patients with native BJI (mean age, 44.4 ± 15.7 years) were analysed. Fifteen cases were paraplegic patients with ischial pressure sores breaching the hip capsule. Other cases included eight other hip infections, four tibial infections and two foot infections. Infections were mostly polymicrobial (n = 23; 79.3%), including Staphylococcus aureus (n = 13; 8 methicillin-resistant). Klebsiella pneumoniae (n = 13) was the most frequent ESBL-producing species identified, followed by Escherichia coli (n = 10), including 3 E. coli/K. pneumoniae co-infections, and Enterobacter spp. (n = 9). ESBL-PE were rarely susceptible to fluoroquinolones (n = 4; 13.8%). Most therapies were based on carbapenems (n = 22) and combination therapies (n = 19). The median duration of treatment was 41 (5-60) days. Primary control of the infection was achieved in 62.1% (18/29) of cases and up to 86.2% after second look surgeries, after a median follow-up of 6 (1-36) months. Infection with ESBL-producing K. pneumoniae was associated with failure (P = 0.001), whereas age, infection location, prior colonisation and antimicrobial therapy were not found to be predictors of outcome. ESBL-PE native BJIs are often polymicrobial and fluoroquinolone-resistant infections caused by K. pneumoniae, highlighting the need for expert centres with pluridisciplinary meetings with experienced surgeons.

Hip Joint Infections Caused by Multidrug-Resistant Enterobacterales Among Patients With Spinal Cord Injury: Experience of a Reference Center in the Greater Paris Area.

Background: We aimed to describe the management and treatment of hip joint infections caused by multidrug-resistant Enterobacterales among patients with spinal cord injury (SCI). Methods: We included all hip joint infections associated with grade IV decubitus ulcers caused by extended-spectrum beta-lactamase producing Enterobacterales (ESBL-PE) and carbapenemase-producing Enterobacterales treated in a reference center for bone and joint infections over 9 years in a retrospective study. Results: Seventeen SCI patients with ischial pressure ulcers breaching the hip capsule (mean age 52 ± 15 years) were analyzed. In 16 patients, paraplegia was secondary to trauma and 1 was secondary to multiple sclerosis. Infections were mostly polymicrobial (n = 15; 88.2%), notably caused by Klebsiella pneumoniae (n = 10) and Staphylococcus aureus (n = 10). The carbapenemases identified were exclusively OXA-48-type (n = 3) including 2 isolates coexpressed with ESBL-PE within the same bacterial host. Multidrug-resistant Enterobacterales were commonly resistant to fluoroquinolones (n = 12; 70.6%). Most therapies were based on carbapenems (n = 10) and combination therapies (n = 13). Median duration of treatment was 45 (6-60) days. Of 17 cases of hip joint infections, 94.1% (n = 16) benefited from a femoral head and neck resection. Infection control was initially achieved in 58.8% (n = 10) of cases and up to 88.2% after revision surgeries, after a median follow-up of 3 (1-36) months. Conclusions: Hip infections among SCI patients caused by multidrug-resistant Enterobacterales are often polymicrobial and fluoroquinolones-resistant infections caused by Klebsiella pneumoniae and S aureus, highlighting the need for expert centers with pluridisciplinary meetings associating experienced surgeons, clinical microbiologists, and infectious disease specialists.

Specific real-time PCR for simultaneous detection and identification of Legionella pneumophila serogroup 1 in water and clinical samples.

Legionella pneumophila, a bacterium that replicates within aquatic amoebae and persists in the environment as a free-living microbe, is the causative agent of Legionnaires' disease. Among the many Legionella species described, L. pneumophila is associated with 90% of human disease, and within the 15 serogroups (Sg), L. pneumophila Sg1 causes more than 84% of Legionnaires' disease worldwide. Thus, rapid and specific identification of L. pneumophila Sg1 is of the utmost importance for evaluation of the contamination of collective water systems and the risk posed. Previously we had shown that about 20 kb of the 33-kb locus carrying the genes coding for the proteins involved in lipopolysaccharide biosynthesis (LPS gene cluster) by L. pneumophila was highly specific for Sg1 strains and that three genes (lpp0831, wzm, and wzt) may serve as genetic markers. Here we report the sequencing and comparative analyses of this specific region of the LPS gene cluster in L. pneumophila Sg6, -10, -12, -13, and -14. Indeed, the wzm and wzt genes were present only in the Sg1 LPS gene cluster, which showed a very specific gene content with respect to the other five serogroups investigated. Based on this observation, we designed primers and developed a classical and a real-time PCR method for the detection and simultaneous identification of L. pneumophila Sg1 in clinical and environmental isolates. Evaluation of the selected primers with 454 Legionella and 38 non-Legionella strains demonstrated 100% specificity. Sensitivity, specificity, and predictive values were further evaluated with 209 DNA extracts from water samples of hospital water supply systems and with 96 respiratory specimens. The results showed that the newly developed quantitative Sg1-specific PCR method is a highly specific and efficient tool for the surveillance and rapid detection of high-risk L. pneumophila Sg1 in water and clinical samples.

Diagnostic challenges of central nervous system infection: extensive multiplex panels versus stepwise guided approach.

BACKGROUND: Cerebrospinal fluid (CSF) testing is a key component for the diagnosis of central nervous system (CNS) infections. Current meningitis and encephalitis management guidelines agree on the need for CSF molecular testing in combination with other direct and indirect biological testing, both in CSF and blood. Multiplex molecular tests have been developed to reduce turnaround times and facilitate the diagnostic approach. OBJECTIVES: We aim to discuss the role of multiplex molecular panels in the management of CNS infections. SOURCES: The MEDLINE database and the grey literature have been searched for relevant articles. CONTENT: New molecular multiplex panels are being developed to simultaneously detect a large array of neuropathogens in CSF. Although one of these assays has been US Food and Drug Administration-approved, extensive analytical and clinical validation is still missing, and suboptimal performance related issues have been raised. Its use has been associated with decreased costs, reduced length of hospital stay and reduced antiviral therapy administration in retrospective, industry-sponsored studies. The pros and cons of this multiplex syndromic approach are discussed in this narrative review. IMPLICATIONS: Molecular multiplex CNS infection diagnosis panels have been developed and present several attractive features, including ease of use and low turnaround time. However, suboptimal analytical performances render these tests difficult to use without additional confirmatory tests. Such panels are not comprehensive nor adapted to all situations, depending on the epidemiological or clinical context. Overall, available data in the literature currently do not support the use of a multiplex PCR panel in clinical routine as a 'stand-alone' molecular assay. Except in restricted laboratory capacity settings where such easy-to-use multiplex panels offer the diagnostic means that would otherwise not be available, the stepwise testing approach remains a more rational option. Serological testing both in blood and CSF should not be neglected, but it represents essential complementary tools regarding some neuropathogens.

Case series of carbapenemase-producing Enterobacteriaceae osteomyelitis: Feel it in your bones.

OBJECTIVES: Limited data have been reported regarding osteomyelitis due to carbapenemase-producing Enterobacteriaceae (CPE), including co-infections with extended-spectrum ß-lactamase (ESBL)-producing micro-organisms. METHODS: We conducted a retrospective study in a reference centre for bone and joint infections from 2011 to 2019 among patients infected with CPE. RESULTS: Nine patients (mean age 46.8 ± 16.6 years), including three with infected implants, were identified. Infections were mostly polymicrobial (n = 8/9), including Staphylococcus aureus (n = 6/9). CPE were mainly OXA-48-type, associated with ESBL-producing Enterobacteriaceae (n = 8/9), of which 5/9 isolates were Klebsiella pneumoniae. Control of the infection was achieved in seven cases. CONCLUSIONS: CPE osteomyelitides are essentially polymicrobial and fluoroquinolone-resistant infections, highlighting the need for efficient surgery with implant removal.

Multicenter evaluation of a transcription-reverse transcription concerted assay for rapid detection of mycobacterium tuberculosis complex in clinical specimens.

A European multicenter study was performed to evaluate the performance of a new method, based on the transcription-reverse transcription concerted reaction (TRC-2), which enabled one-step amplification and real-time detection of the Mycobacterium tuberculosis 16S rRNA target directly in clinical specimens. A total of 633 respiratory and nonrespiratory specimens were tested, and the results were compared with those from smears and cultures. A total of 129 patients (Paris center) were followed up in order to evaluate the clinical performance of TRC-2. By using M. tuberculosis complex strains to inoculate sterile sputa, the detection limit of TRC-2 was found to be 30 to 50 CFU/ml. A total of 548 respiratory specimens and 59 extrapulmonary specimens were assessable. For pulmonary specimens, the sensitivities of TRC-2 and acid-fast smear were 86.8% and 50.4%, respectively (P = 0.002). The specificities were 97.5% and 100%, respectively. For extrapulmonary specimens, the sensitivities of TRC-2 and acid-fast smear were 83.3% and 8.3% (P < 0.0001), and the specificities were 95.8% and 100%, respectively. Fifteen of 129 patients were diagnosed with pulmonary tuberculosis (TB). The sensitivities of culture and TRC-2 were 80% (12/15) and 86.7% (13/15) (P = 0.16), and the specificities were 100% and 93.9%, respectively. Based on an 11.6% incidence of TB in our population, the positive predictive values of TRC-2 and culture were 81.3% and 100%, respectively, and the negative predictive values were 98.2% and 97.4%, respectively. These results demonstrated that detection of M. tuberculosis complex in clinical specimens by TRC-2 with ready-to-use reagents was an efficient and rapid method for the diagnosis of pulmonary and extrapulmonary TB.

IFNgamma and antibody responses among French nurses during a tuberculosis contact tracing investigation.

STUDY: A comparative study which compared PPD skin testing inserted according to the French Society of Pneumology's recommendations and interferon gamma release assay (IGRA) (QuantiFERON((R)) TB Gold In-tube, QF-TB-IT, Cellestis, Carnegie, Australia) was performed during a tuberculosis contact investigation in our hospital. PATIENTS: Nineteen French health-care workers (HCWs) volunteered to participate. All of the HCW enrolled were BCG vaccinated and had a normal chest X-ray at entry. RESULTS: Among the HCW, 68.4% were TST positive. By comparison, only 31.6% had a positive QF-TB-IT result. We took advantage of the negative tube and the corresponding plasma for antibody detection by ELISA. None were ELISA positive. Fourteen HCWs were followed up. None of the HCWs accepted a course of antiTB chemoprophylaxis. Despite the difficulty in establishing a trend in kinetics, we saw the complexity of interpretation of a dynamic T-cell response after contact with an index case. CONCLUSION: This initial and first French picture provides us with the observation that only 44% of TST-positive HCW were IGRA positive, and the IGRA test allowed the detection of LTBI in two TST negative HCWs.

[Results of a prospective standardized study of 30 patients with chronic neurological and cognitive disorders after tick bites]. / Enquête étiologique standardisée sur une cohorte de 30 patients atteints de troubles neurologiques et cognitifs chroniques après piqûre de tiques results of a prospective standardized study of 30 patients with chronic neurological and cognitive disorders after tick bites.

OBJECTIVE: Patients with chronic neurological disorders and cognitive impairment after tick bites are difficult to manage despite standard antibiotic therapy for Lyme disease. We wanted to correctly assess the disorders. METHODS: Thirty patients were hospitalized for a standardized evaluation of their disorders: clinical examination, biological and serological studies, cerebral MRI, CSF study, neurophysiological exams, and neuropsychological evaluation of cognitive functions. RESULTS: Clinical and biological results were non informative. We observed significant CSF abnormalities (64%), MRI Flair pictures (41%), neurophysiological exams (47%), and cognitive evaluation (100%). CONCLUSIONS: A large and standardized evaluation should be made for each patient to improve the management and probably the treatment of these complex chronic symptoms observed after tick bites.

Tuberculosis in European cities: establishment of a patient monitoring system over 10 years in Paris, France.

BACKGROUND: Tuberculosis (TB) is a persistent public health problem in European cities. France has been unable to report on treatment outcomes until now, and it is not known whether the World Health Organization (WHO) target cure rate of 85% has been met. METHODS: All patients placed under treatment in four hospitals and five out-patient Social Medical Centres in Paris were followed up between 1996 and 2005. Patient monitoring and evaluation were performed using a new software programme, TB-INFO. RESULTS: In a cohort of 1127 patients, 76% had pulmonary TB, of whom 39% were smear-positive, 81% were foreign-born and 9.3% were human immunodeficiency virus positive. At the end of the follow-up, 16% were cured and 54% had completed treatment. Among the 1118 non-multidrug-resistant patients, these percentages were 17% and 46%, respectively, for smear-positive pulmonary patients. Some patients died (1.9%) or failed treatment (0.1%), but many more defaulted (20.5%) as they interrupted treatment (1.5%), were lost to follow-up (19.5%) or were transferred out (7.9%). CONCLUSIONS: This 10-year follow-up of TB patients, managed with TB-INFO software, shows that a patient monitoring system can be implemented in France, providing essential information. Treatment success in this cohort of patients was far below the WHO target.

Mediation of NGF-stimulated extracellular matrix invasion by the human melanoma low-affinity p75 neurotrophin receptor: melanoma p75 functions independently of trkA.

Although overexpression of the low-affinity p75 neurotrophin receptor (p75NTR) is frequently associated with advanced stages of human melanoma progression, the functional significance of this finding is unknown. We examined whether the degree of cell surface expression of p75NTR in human melanoma cell variants determines their extent of invasion stimulated by nerve growth factor (NGF). Treatment of MeWo melanoma cells or a metastatic spontaneous wheat germ agglutinin-resistant variant subline (70W) of MeWo cells with 2.5S NGF resulted in a dose-dependent enhancement of invasion through a reconstituted basement membrane. This effect was most pronounced with the 70W subline that exhibits brain-metastasizing potential in nude mice but was not found with a poorly metastatic MeWo variant subline (3S5). The expression of p75NTR as determined by Northern blotting and immunoprecipitation analysis of 125I-labeled cell surface proteins correlated with NGF-stimulated invasion. The MeWo melanoma sublines used in this study did not express p140proto-trkA mRNA or any p140proto-trkA variant transcripts including p70trkA as determined by Northern analysis and RT-PCR analysis. Thus, these melanoma cells would not be expected to form functional p75-p140 heterodimers or p140-p140 homodimers capable of transducing an NGF-generated signal to p140proto-trkA cytoplasmic substrates. These cells did express authentic p145trkC transcripts. However, NGF did not catalytically activate p145trkC receptors via increased tyrosine phosphorylation as would be expected if p145trkC participated in the signaling established by NGF. Furthermore, a NGF-stimulated purine-analogue-sensitive kinase activity was found to coimmunoprecipitate with p75NTR. This p75NTR-associated kinase may coordinate initial signaling events evoked by p75NTR ligand interaction. Addition of 2.5S NGF, at concentrations that should saturate cell surface p75NTR, to matrix-adherent cultures of human MeWo and 70W but not 3S5 melanoma cells suppressed the expression of 92-kDa type IV collagenase and stimulated the production of 72-kDa type IV collagenase in its fully active 68-kDa form. In the absence of p140proto-trkA, the matrix-dependent effects of NGF on metalloproteinase expression of brain-metastatic 70W melanoma cells suggest a signaling role for the low-affinity melanoma p75NTR receptor and its associated purine-analogue-sensitive kinase in signaling enhanced matrix penetration of NGF-rich stromal microenvironments such as the brain.

[Advantages and drawbacks of in vitro Interferon-gamma/T cell assays compared to the Mantoux test for the diagnosis of tuberculosis]. / Avantages et limites des tests sanguins in vitro lymphocytes T/interféron gamma comparativement au test intradermique à la tuberculine pour le diagnostic de tuberculose.

The development of in vitro blood tests that measure the delayed hypersensitivity reaction developed after contact with Mycobacterium tuberculosis will change progressively the diagnosis of M. tuberculosis infection. These blood assays (Quantiferon TB Gold, Cellestis, Australia; T-SPOT.TB, Oxford Immunotec, United Kingdom) use specific, complex M. tuberculosis antigens (ESAT-6 and CFP-10), whereas the intra-dermal Mantoux test is done with tuberculin, a complex mixture of more than 200 antigens. ESAT-6 and CFP-10 are absent from all the BCG vaccine strains used throughout the world. Significant improvement in the specificity with equivalent or increased sensitivity of the in vitro tests compared to the Mantoux test will lead eventually to replacement of the latter.

[New immunological tests in the diagnosis of tuberculosis]. / Les nouveaux tests immunologiques dans le diagnostic de la tuberculose (TB or not TB).

INTRODUCTION: Targeted testing and treatment of individuals with latent tuberculosis infection (LTBI), at high risk of progression to active tuberculosis (ATB), are key elements in the battle against tuberculosis, both in France and in many parts of the world. Though the finding of tubercle bacilli is the essential examination for the diagnosis of ATB, there is no indisputable test for LTBI. BACKGROUND: The help currently given to the diagnosis of LTBI by the degree of positivity of the tuberculin skin test (TST) is limited, both operationally and logistically, in populations vaccinated with BCG or sensitised by atypical mycobacteria, and by its low sensitivity in those immuno-suppressed persons who are at greatest risk of progression. Moreover the TST has other operational limitations linked to return visits, repeat testing causing a boosting effect and subjective interpretation. A new approach follows the availability of two biological tests for the diagnosis of LTBI (QuantiFERON-TB and T-SPOT-TB) that measure the in-vitro production of interferon gamma (IFN-gamma) by the blood mononuclear cells in response to M. tuberculosis specific antigens (ESAT-6 and CFP10). This revue analyses the published studies, undertaken with varying numbers of patients, that evaluate the diagnostic accuracy of these two tests in comparison with TST. However, validation is handicapped by the lack of a "gold standard" for the diagnosis of LTBI. These studies demonstrate similar levels of specificity for the two biological tests. They are statistically higher than those for TST, particularly in populations vaccinated by BCG. On the other hand, their sensitivity was at least equivalent to that of TST and, in certain studies, superior with T-SPOT-TB. Finally, several studies in contacts have been undertaken with the aim of measuring the concordance between these biological tests and TST. The essential finding is of a very good correlation between positivity of the biological tests and the degree of exposure of the contacts. These tests have additional operational advantages over TST: completed in one visit, results available in 24 hours, absence of inter and intra observer divergence, detection of potential immuno-depression and avoidance of boosting by repeat testing. VIEWPOINT: Currently, however, these biological tests present several operational limits: lower sensitivity in severe disease, incomplete data in immuno-suppressed subjects and in children, lack of predictive value for future development of ATB, lack of distinction between LTBI and ATB. Numerous clinical studies are under way, in France and elsewhere, in order to reduce these limitations and to allow the appropriate incorporation of these tests into protocols for the diagnosis of tuberculosis. CONCLUSIONS: These two biological tests should, in the near future, replace or complement TST in the diagnosis of recent LTBI, leading to their optimal incorporation into the decision making processes of the national plans for the control of tuberculosis.

Epidemiology of infectious encephalitis causes in 2016.

We performed a literature search in the Medline database, using the PubMed website. The incidence of presumably infectious encephalitis is estimated at 1.5-7 cases/100,000 inhabitants/year, excluding epidemics. Infectious encephalitis and immune-mediated encephalitis share similar clinical signs and symptoms. The latter accounts for a significant proportion of presumably infectious encephalitis cases without any established etiological diagnosis; as shown from a prospective cohort study where 21% of cases were due to an immune cause. Several infectious agents are frequently reported in all studies: Herpes simplex virus (HSV) is the most frequent pathogen in 65% of studies, followed by Varicella-zoster virus (VZV) in several studies. Enteroviruses are also reported; being the most frequent viruses in two studies, and the 2nd or 3rd viruses in five other studies. There are important regional differences, especially in case of vector-borne transmission: Asia and the Japanese encephalitis virus, Eastern and Northern Europe/Eastern Russia and the tick-borne encephalitis virus, Northern America and Flavivirus or Alphavirus. Bacteria can also be incriminated: Mycobacterium tuberculosis and Listeria monocytogenes are the most frequent, after HSV and VZV, in a French prospective study. The epidemiology of encephalitis is constantly evolving. Epidemiological data may indicate the emergence and/or dissemination of new causative agents. The dissemination and emergence of causative agents are fostered by environmental, social, and economical changes, but prevention programs (vaccination, vector controls) help reduce the incidence of other infectious diseases and associated encephalitis (e.g., measles).

[The role of human dendritic cells in tuberculosis: protector or non-protector?]. / Rôle des cellules dendritiques humaines dans la tuberculose: protecteur ou non protecteur?

INTRODUCTION: Mycobacterium tuberculosis, the cause of tuberculosis remains a pathogenic organism capable of infecting a large number of individuals and of resisting the immune response of the infected host. The main constituents of this response are the antigen presenting cells such as dendritic cells, macrophages and T lymphocytes. BACKGROUND: Comparative study of the interactions between M. tuberculosis and the antigen presenting cells has shown that dendritic cells do not permit intracellular growth of M. tuberculosis, unlike that seen in macrophages. A hostile intracellular compartment creates a bacteriostatic environment. M. tuberculosis is internalised by binding to a C-type lectin receptor (DC-SIGN). VIEWPOINT: This receptor recognises polysaccharide compounds on the surface of M. tuberculosis. This sugar-lectin bond may compensate for the bond between bacterial compounds and Toll receptors, partially inhibiting the protective inflammatory reaction or compensating for an excessive inflammatory reaction. CONCLUSIONS: This bond encourages both the persistence of quiescent bacteria in the dendritic cells and the reciprocal adaptation of the host and the bacteria over the course of time.

Vaccine strategies against bacterial pathogens in cystic fibrosis patients.

A large number of cystic fibrosis pathogens such as bacteria of the Burkholderia cepacia complex, Pseudomonas aeruginosa, or Mycobacterium abscessus are associated with complex therapeutic problems due to their inherent resistance to antibiotics. No vaccine is currently available against those pathogens. Vaccines are therefore crucial to combat these multidrug-resistant bacteria in specific clinical situations including cystic fibrosis. Various strategies may be considered to develop these vaccines. Similar virulence factors are expressed during the infection with various pathogens; they could thus be used as antigen to assess cross-protection. Many clinical trials are currently being conducted to try and develop a prophylactic treatment for patients presenting with cystic fibrosis.

Prostate carcinoma cell death resulting from inhibition of proteasome activity is independent of functional Bcl-2 and p53.

The ATP/ubiquitin-dependent 26S proteasome is a central regulator of cell cycle progression and stress responses. While investigating the application of peptide aldehyde proteasome inhibitors to block signal-induced IkappaBalpha degradation in human LNCaP prostate carcinoma cells, we observed that persistent inhibition of proteasomal activity signals a potent cell death program. Biochemically, this program included substantial upregulation of PAR-4 (prostate apoptosis response-4), a putative pro-apoptotic effector protein and stabilization of c-jun protein, a potent pro-death effector in certain cells. We also observed modest downregulation of bcl-XL, a pro-survival effector protein. However, in contrast to some recent reports stable, high level, expression of functional bcl-2 protein in prostate carcinoma cells failed to signal protection against cell death induction by proteasome inhibitors. Also in disagreement to a recent report, no evidence was found for activation of the JNK stress kinase pathway. A role for p53, a protein regulated by the proteasome pathway, was ruled out, since comparable cell death induction by proteasome inhibitors occurred in PC-3 cells that do not express functional p53 protein. These data signify that the ubiquitin/proteasome pathway represents a potential therapeutic target for prostate cancers irrespective of bcl-2 expression or p53 mutations.

E1A-mediated paclitaxel sensitization in HER-2/neu-overexpressing ovarian cancer SKOV3.ip1 through apoptosis involving the caspase-3 pathway.

HER-2/neu-overexpressing breast cancer cells are more resistant to the chemotherapeutic agent paclitaxel (Taxol) than low-HER-2/neu-expressing breast cancer cells, and the adenoviral type 5 EIA can down-regulate HER-2/neu overexpression. Therefore, in this study, we asked (a) whether EIA might sensitize response to paclitaxel in human HER-2/neu-overexpressing ovarian cancer cells, and, if so, what is the mechanism responsible; and (b) whether this enhanced chemosensitivity would translate into a therapeutic effect in an ovarian cancer xenograft model. Consequently, we demonstrated that: (a) adenovirus type 5 E1A could enhance the sensitivity of paclitaxel in paclitaxel-resistant HER-2/neu-overexpressing human ovarian cancer cells in vitro by inducing apoptosis, (b) this induction was heavily dependent on activation of the caspase-3 pathway, and (c) nude mice bearing i.p. HER-2/neu-overexpressing human ovarian cancer cells and treated with both paclitaxel and E1A gene therapy survived significantly longer than did mice treated only with paclitaxel or E1A gene therapy. Thus, we concluded that the E1A gene enhanced both the in vitro and in vivo sensitivity of paclitaxel in paclitaxel-resistant HER-2/ neu-overexpressing ovarian cancer SKOV3.ipl cells. Because a Phase I clinical trial using E1A gene targeted to HER-2/neu down-regulation has recently been completed, the current study also provided a scientific basis to further develop a novel therapy that combines paclitaxel and E1A gene therapy and its testing in a Phase II trial.

Occupational determinants of methicillin-resistant Staphylococcus aureus colonization among healthcare workers: a longitudinal study in a rehabilitation center.

BACKGROUND Staphylococcus aureus carriage among healthcare workers (HCWs) is a concern in hospital settings, where it may provide a reservoir for later infections in both patients and staff. Earlier studies have shown that the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage in HCWs is highly variable, depending notably on location, hospital department type, MRSA prevalence among patients, and type of contacts with patients. However, MRSA incidence in HCWs and its occupational determinants have seldom been studied. METHODS A prospective, observational cohort study was conducted between May and October 2009 in a French rehabilitation center hospital. HCWs and patients were screened weekly for S. aureus nasal carriage. Methicillin-susceptible S. aureus and MRSA prevalence and incidence were estimated and factors associated with MRSA acquisition were identified using generalized estimating equation regression methods. RESULTS Among 343 HCWs included in the analysis, the average prevalence was 27% (95% CI, 24%-29%) for methicillin-susceptible S. aureus and 10% (8%-11%) for MRSA. We observed 129 MRSA colonization events. According to the multivariable analysis, high MRSA prevalence level among patients and HCW occupation were significantly associated with MRSA acquisition in HCWs, with assistant nurses being more at risk than nurses (odds ratio, 2.2; 95% CI, 1.4-3.6). CONCLUSIONS Our findings may help further our understanding of the transmission dynamics of MRSA carriage acquisition in HCWs, suggesting that it is notably driven by carriage among patients and by the type of contact with patients.

Caspase-independent apoptosis in infected macrophages triggered by sulforaphane via Nrf2/p38 signaling pathways.

Mycobacterium abscessus (Mabs), a non-tuberculous mycobacterium, is an emerging and rapidly growing opportunistic pathogen that is frequently found in patients with cystic fibrosis and in immunosuppressed patients. Its high tolerance to antibiotics is of great concern for public health. In this study, our results showed that human THP-1-derived macrophages infected with M. abscessus presented an increase in ROS production and cell necrosis. In addition, M. abscessus infection triggered activation of the Nuclear factor E2-related factor 2 (Nrf2) signaling pathway, and the induction of HO-1 and NQO1 expression levels. Interestingly, pretreatment of macrophages with sulforaphane (SFN), an activator of the antioxidant key regulator Nrf2, followed by M. abscessus infection significantly decreased mycobacterial burden. We demonstrated that this reduction in mycobacterial growth was due to an activation in cell apoptosis in SFN-pretreated and M. abscessus-infected macrophages. Pretreatment with specific MAPK inhibitors, PD98059, SP600125, and SB203580 to ERK, JNK, and p38 respectively, failed to inhibit induction of Nrf2 expression, suggesting that Nrf2 signaling pathway was upstream of MAPK signaling. Activation of cell apoptosis was caspase 3/7 independent but p38 MAPK dependent. Moreover, p38 MAPK induction was abolished in macrophages transfected with Nrf2 siRNA. In addition, p38 inhibitor abolished Nrf2-dependent apoptosis in infected macrophages. Taken together, our results indicate that modulation of the Nrf2 signaling using Nrf2 activators may help potentiate the actual drug therapies used to treat mycobacterial infection.