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1.
Infect Dis Now ; 53(8): 104776, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37648080

ABSTRACT

OBJECTIVES: Prosthetic joint infections (PJIs) due to the Clostridium species have not been widely investigated. We aimed to characterize these uncommon infections. METHODS: We conducted a retrospective study between 2003 and 2020 in six French hospitals combined with a review of the literature. RESULTS: The main conclusions obtained from the 16 patients included were reinforced by the literature analysis: (i) Clostridium perfringens was the most frequently involved species, (ii) patients presented an advanced age at the time of prosthesis placement and infection, (iii) most of the infections were early- or delayed-onset, (iv) the prognosis for these PJIs remains poor, (v) when performed (n = 5), DAIR with 12-week antimicrobial therapy led to a favorable outcome in 80% of cases. CONCLUSIONS: Given the low incidence of this infection, our work represents the largest series of clostridial PJIs reported to date and highlights some specificities of these infections. Further prospective studies are needed to confirm these results.


Subject(s)
Arthritis, Infectious , Humans , Treatment Outcome , Retrospective Studies , Clostridium , Prostheses and Implants
2.
Benef Microbes ; 11(4): 391-401, 2020 Aug 12.
Article in English | MEDLINE | ID: mdl-32720833

ABSTRACT

Salmonella Heidelberg is one of the most common serovar causing foodborne illnesses. To limit the development of digestive bacterial infection, food supplements containing probiotic bacteria can be proposed. Commensal non-toxigenic Bacteroides fragilis has recently been suggested as a next-generation probiotic candidate. By using an original triple co-culture model including Caco-2 cells (representing human enterocytes), HT29-MTX (representing mucus-secreting goblet cells), and M cells differentiated from Caco-2 by addition of Raji B lymphocytes, bacterial translocation was evaluated. The data showed that S. Heidelberg could translocate in the triple co-culture model with high efficiency, whereas for B. fragilis a weak translocation was obtained. When cells were exposed to both bacteria, S. Heidelberg translocation was inhibited. The cell-free supernatant of B. fragilis also inhibited S. Heidelberg translocation without impacting epithelial barrier integrity. This supernatant did not affect the growth of S. Heidelberg. The non-toxigenic B. fragilis confers health benefits to the host by reducting bacterial translocation. These results suggested that the multicellular model provides an efficient in vitro model to evaluate the translocation of pathogens and to screen for probiotics that have a potential inhibitory effect on this translocation.


Subject(s)
Bacterial Translocation , Bacteroides fragilis/physiology , Intestinal Mucosa/microbiology , Salmonella/physiology , Bacterial Translocation/drug effects , Bacteroides fragilis/metabolism , Caco-2 Cells , Coculture Techniques , Culture Media, Conditioned/metabolism , Culture Media, Conditioned/pharmacology , HT29 Cells , Humans , Intestinal Mucosa/cytology , Microbial Interactions , Models, Biological , Probiotics/metabolism , Probiotics/pharmacology
3.
Med Mal Infect ; 49(7): 540-544, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31277834

ABSTRACT

OBJECTIVE: We aimed to describe the effectiveness and safety of the moxifloxacin-rifampicin combination in non-staphylococcal Gram-positive orthopedic implant-related infections. METHODS: Patients treated with the moxifloxacin-rifampicin combination for an implant-related infection from November 2014 to November 2016 were retrospectively identified from the database of the referral centers for bone and joint infections in Western France. RESULTS: Twenty-three cases of infection due to Streptococcus spp. (n=12), Cutibacteriumacnes (n=6), and Enterococcus faecalis (n=5) were included. Ten patients with hip prosthesis were included. Infection was polymicrobial in 11 cases. According to the MIC, moxifloxacin was 1.5 to 11.7 times as active as levofloxacin against non-staphylococcal Gram-positive bacteria. We reported an 81.8% success rate, and no severe adverse effect. CONCLUSION: The moxifloxacin-rifampicin combination is a valuable alternative for the treatment of non-staphylococcal Gram-positive implant-related infections because of the good activity of moxifloxacin against these bacteria and the potential activity on the biofilm.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/etiology , Hip Prosthesis/adverse effects , Moxifloxacin/administration & dosage , Prosthesis-Related Infections/drug therapy , Rifampin/administration & dosage , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/adverse effects , Drug Combinations , Enterococcus faecalis , Female , Humans , Male , Middle Aged , Moxifloxacin/adverse effects , Propionibacteriaceae , Retrospective Studies , Rifampin/adverse effects , Streptococcal Infections , Treatment Outcome
4.
Clin Rheumatol ; 38(7): 1985-1992, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30850963

ABSTRACT

OBJECTIVE: To evaluate the diagnostic performance of bacterial identification by broad-range polymerase chain reaction (PCR) of ribosomal DNA (rDNA) 16 s (16S rDNA PCR) for the diagnosis of septic arthritis on native joints. METHODS: Patients with acute mono or oligoarthritis who underwent synovial fluid puncture and prospective follow-up allowing definitive diagnosis (septic arthritis, crystal related disease, chronic inflammatory arthritis, undifferentiated arthritis) were recruited in this single-center study. Systematic analysis of synovial fluid included leukocytes count, search for urate and pyrophosphate crystals with polarized light microscopy, direct bacteriological examination (gram staining), bacteriological culture, and 16S rDNA PCR. RESULTS: Ninety-five patients were included, 34 of which (35.8%) had septic arthritis. Nineteen (20.0%) patients had received probabilistic antibiotic therapy prior to joint puncture. Gram + cocci infection accounted for 79.4% of septic arthritis, of which nearly half (47.1%) was caused by Staphylococcus aureus. Eight (23.5%) septic arthritis patients had a 16S rDNA PCR positive in the synovial fluid with an AUC of 0.618 (95% CI, 0.493-0.742), a sensitivity of 0.24 (95% CI, 0.12-0.40), and a specificity of 1.00 (95% CI 0.94-1.00). The diagnostic performance of 16S rDNA PCR was lower than that of direct examination (AUC at 0.691, CI 95%, 0.570-0.812), blood cultures (AUC at 0.727, CI 95%, 0.610-0.844), and culture (0.925, CI 95%, 0.856-0.994) for the diagnosis of septic arthritis. There was no difference in the positivity of 16S rDNA PCR according to previous exposure to antibiotics. CONCLUSIONS: 16 s rDNA PCR in the synovial fluid does not improve the diagnostic performance of septic arthritis on native adult joints, particularly for Gram-positive cocci infections.


Subject(s)
Arthritis, Infectious/diagnosis , Arthritis, Infectious/microbiology , Bacterial Infections/diagnosis , Synovial Fluid/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Bacterial Infections/complications , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Polymerase Chain Reaction , Prospective Studies , RNA, Ribosomal, 16S/genetics , Sensitivity and Specificity , Young Adult
5.
Clin Microbiol Infect ; 24(1): 83.e1-83.e6, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28559002

ABSTRACT

OBJECTIVES: Prosthetic joint infections (PJI) are responsible for significant morbidity and mortality and their number continues to rise. Their management remains complex, especially the microbiological diagnosis. Besides 'homemade' tests developed by several teams, new molecular biology methods are now available with different analytical performance and usability. METHODS: We studied the performances of one of these tests: ITI® multiplex PCR (mPCR) by the Curetis® company and compared it to either 'optimized' culture or 16S rRNA PCR. We performed a retrospective multicentre study to assess the contributions of mPCR in the diagnosis of PJI. We randomly selected 484 intraoperative specimens among 1252 of various types (biopsy, bone, tissue around the prosthesis, synovial fluid) from 251 patients in seven different hospitals. Each sample was treated according to the recommendations of the manufacturer. RESULTS: In all, 154 out of 164 (93.9%) samples negative in culture were negative with the mPCR. Among the 276 positive samples in culture, 251 (90.9%) were monomicrobial, of which 119 (47.4%) were positive with the mPCR, and 25 (9.1%) were polymicrobial, of which 12 (48%) were positive with the mPCR. The concordance rate of mPCR with culture was 58.1% (53.6%-62.7%) and the concordance rate with 16S rRNA PCR was 70.1% (65.5%-74.6%). CONCLUSION: This new standardized molecular test showed a lack of detection when the bacterial inoculum was low (number of positive media per sample and number of colonies per media) but can be useful when patients have received antibiotic therapy previously.


Subject(s)
Joint Prosthesis/microbiology , Methicillin-Resistant Staphylococcus aureus/genetics , Multiplex Polymerase Chain Reaction/methods , Prosthesis-Related Infections/diagnosis , Prosthesis-Related Infections/microbiology , Staphylococcal Infections/diagnosis , Bacterial Proteins/genetics , Humans , Methicillin Resistance/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Penicillin-Binding Proteins/genetics , Prosthesis-Related Infections/mortality , RNA, Ribosomal, 16S/genetics , Retrospective Studies , Staphylococcal Infections/microbiology
6.
Curr Alzheimer Res ; 15(8): 716-722, 2018.
Article in English | MEDLINE | ID: mdl-27875949

ABSTRACT

Spirochetes are suspected to be linked to the genesis of neurological diseases, including neurosyphillis or neurodegeneration (ND). Impaired iron homeostasis has been implicated in loss of function in several enzymes requiring iron as a cofactor, formation of toxic oxidative species, inflammation and elevated production of beta-amyloid proteins. This review proposes to discuss the link that may exist between the involvement of Treponema spp. in the genesis or worsening of ND, and iron dyshomeostasis. Proteins secreted by Treponema can act directly on iron metabolism, with hemin binding ability (HbpA and HbpB) and iron reductase able to reduce the central ferric iron of hemin, iron-containing proteins (rubredoxin, neelaredoxin, desulfoferrodoxin metalloproteins, bacterioferritins etc). Treponema can also interact with cellular compounds, especially plasma proteins involved in iron metabolism, contributing to the virulence of the syphilis spirochetes (e.g. treponemal motility and survival). Fibronectin, transferrin and lactoferrin were also shown to be receptors for treponemal adherence to host cells and extracellular matrix. Association between Treponema and iron binding proteins results in iron accumulation and sequestration by Treponema from host macromolecules during systemic and mucosal infections.


Subject(s)
Iron/metabolism , Neurodegenerative Diseases/metabolism , Treponema/metabolism , Treponemal Infections/metabolism , Animals , Bacterial Proteins/metabolism , Cytochrome b Group/metabolism , Ferritins/metabolism , Humans , Neurodegenerative Diseases/epidemiology , Neurodegenerative Diseases/microbiology , Spirochaetales/isolation & purification , Spirochaetales/metabolism , Transferrin/metabolism , Treponema/isolation & purification , Treponemal Infections/epidemiology
7.
Eur J Clin Microbiol Infect Dis ; 35(5): 857-66, 2016 May.
Article in English | MEDLINE | ID: mdl-26942744

ABSTRACT

The rapid identification of bacterial species involved in bone and joint infections (BJI) is an important element to optimize the diagnosis and care of patients. The aim of this study was to evaluate the usefulness of matrix-assisted laser desorption ionization mass spectrometry (MALDI-TOF MS) for the rapid diagnosis of bone infections, directly on synovial fluid (SF) or on crushed osteoarticular samples (CS). From January to October 2013, we prospectively analyzed 111 osteoarticular samples (bone and joint samples, BJS) from 78 patients in care at the University Hospital of Rennes, France. The diagnosis procedure leading to the sample collection was linked to a suspicion of infection, inflammatory disease, arthritis, or for any bone or joint abnormalities. Standard bacteriological diagnosis and molecular biology analysis [16S rRNA polymerase chain reaction (PCR) and sequencing] were conducted. In addition, analysis by MALDI-TOF MS was performed directly on the osteoarticular samples, as soon as the amount allowed. Culture, which remains the gold standard for the diagnosis of BJI, has the highest sensitivity (85.9 %) and remains necessary to test antimicrobial susceptibility. The 16S rDNA PCR results were positive in the group with positive BJI (28.6 %) and negative in the group without infection. Direct examination remains insensitive (31.7 %) but more effective than MALDI-TOF MS directly on the sample (6.3 %). The specificity was 100 % in all cases, except for culture (74.5 %). Bacterial culture remains the gold standard, especially enrichment in blood bottles. Direct analysis of bone samples with MALDI-TOF MS is not useful, possibly due to the low inoculum of BJS.


Subject(s)
Arthritis, Infectious/diagnosis , Arthritis, Infectious/microbiology , Bacteria/classification , Bacteria/genetics , Bone Diseases, Infectious/diagnosis , Bone Diseases, Infectious/microbiology , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Polymerase Chain Reaction/methods , Reproducibility of Results , Risk Factors , Sensitivity and Specificity , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
8.
Med Mal Infect ; 46(1): 39-43, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26712077

ABSTRACT

OBJECTIVE: Prosthetic joint infections (PJI) may be cured in selected patients with debridement and prosthesis retention. We aimed to identify predictors of failure to better target patients most likely to benefit from this conservative strategy. METHODS: Observational study of patients presenting with PJI initially treated at our hospital with debridement between 2008 and 2011, with>6 months of post-treatment follow-up. RESULTS: Sixty consecutive patients presenting with PJI (hip, n=34; knee, n=26) fulfilled the inclusion criteria. Failures (n=20, 33%), predefined as persistence of PJI signs or relapses, were managed with additional surgery (n=17) and/or lifelong suppressive antibiotic treatment (n=6). Variables independently associated with failure: previous surgery on the prosthetic joint (OR: 6.3 [1.8-22.3]), Staphylococcus aureus PJI (OR: 9.4 [1.6-53.9]), post-debridement antibiotic treatment for <3 months (OR: 20.0 [2.2-200]). CONCLUSION: Previous surgery, S. aureus PJI, and short duration antibiotic treatment are associated with an increased risk of failure after debridement.


Subject(s)
Arthritis, Infectious/surgery , Debridement , Prosthesis-Related Infections/surgery , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Arthritis, Infectious/drug therapy , Combined Modality Therapy , Comorbidity , Female , Follow-Up Studies , Hip Prosthesis/adverse effects , Humans , Knee Prosthesis/adverse effects , Male , Prosthesis-Related Infections/drug therapy , Reoperation , Staphylococcal Infections/drug therapy , Staphylococcal Infections/etiology , Staphylococcal Infections/surgery , Treatment Failure
9.
Ann Chir Plast Esthet ; 60(6): 490-4, 2015 Dec.
Article in French | MEDLINE | ID: mdl-26321308

ABSTRACT

The incidence of prosthesis infections after breast reconstruction is of the order of 4% to 13% according to the literature. In surgical patients, Staphylococcus aureus (S. aureus) is the bacterial species most often responsible for surgical site infections. In cardiac surgery, screening for carriage of S. aureus and preoperative decontamination are carried out routinely before prosthetic surgery. We retrospectively reviewed data from patients at our institution between January 2011 and December 2013. Our series showed that the prosthesis infection rates were in the range of 5.92% in 2008 with an ISO rate of S. aureus 3.61%. Routine screening for prosthetic reconstructions was performed to assess the impact of preoperative decontamination patients in carriers of S. aureus. This screening was done in 381 patients: 17.8% of patients were carriers of S. aureus ; 11 patients have an ISO (or an incidence rate of 2.88%) ; 5 patients have an ISO S. aureus (an incidence of S. aureus ISO 1.3%). The introduction of the screening process, allowed a drop of 5.92% ISO rate at 1.46% with a passage of S. aureus SSI rates of 3, 60% to 0.72%. In the near future, studies are needed to confirm these encouraging results, to demonstrate the efficacy of preoperative decontamination in carriers of S. aureus patients before laying prosthesis.


Subject(s)
Mammaplasty , Preoperative Care , Prosthesis-Related Infections/prevention & control , Staphylococcus aureus/isolation & purification , Surgical Wound Infection/prevention & control , Anti-Bacterial Agents/therapeutic use , Female , Humans , Mupirocin/therapeutic use , Nasal Cavity/microbiology , Prospective Studies , Prosthesis-Related Infections/microbiology , Staphylococcal Infections/diagnosis , Staphylococcal Infections/drug therapy , Surgical Wound Infection/microbiology
10.
Lett Appl Microbiol ; 57(4): 303-9, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23725093

ABSTRACT

UNLABELLED: In oral microbiome, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of fastidious Capnocytophaga species. The performances of six culture media (blood agar, chocolate blood agar, VCAT medium, CAPE medium, bacitracin chocolate blood agar and VK medium) were compared with literature data concerning five other media (FAA, LB, TSBV, CapR and TBBP media). To understand variable growth on selective media, the MICs of each antimicrobial agent contained in this different media (colistin, kanamycin, trimethoprim, trimethoprim-sulfamethoxazole, vancomycin, aztreonam and bacitracin) were determined for all Capnocytophaga species. Overall, VCAT medium (Columbia, 10% cooked horse blood, polyvitaminic supplement, 3·75 mg l(-1) of colistin, 1·5 mg l(-1) of trimethoprim, 1 mg l(-1) of vancomycin and 0·5 mg l(-1) of amphotericin B, Oxoid, France) was the more efficient selective medium, with regard to the detection of Capnocytophaga species from oral samples (P < 0·001) and the elimination of commensal clinical species (P < 0·001). The demonstrated superiority of VCAT medium, related to its antibiotic content, made its use indispensable for the optimal isolation of Capnocytophaga species from polymicrobial samples. SIGNIFICANCE AND IMPACT OF THE STUDY: Isolation of Capnocytophaga species is important for the proper diagnosis and treatment of the systemic infections they cause and for epidemiological studies of periodontal flora. We showed that in pure culture, a simple blood agar allowed the growth of all Capnocytophaga species. Nonetheless, in oral samples, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of Capnocytophaga species. The demonstrated superiority of VCAT medium made its use essential for the optimal detection of this bacterial genus. This work showed that extreme caution should be exercised when reporting the isolation of Capnocytophaga species from oral polymicrobial samples, because the culture medium is a determining factor.


Subject(s)
Anti-Bacterial Agents/analysis , Capnocytophaga/growth & development , Capnocytophaga/metabolism , Culture Media/metabolism , Gram-Negative Bacterial Infections/microbiology , Mouth/microbiology , Anti-Bacterial Agents/metabolism , Capnocytophaga/isolation & purification , Culture Media/chemistry , France , Humans
11.
J Hosp Infect ; 79(2): 141-6, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21807440

ABSTRACT

Quaternary ammonium compounds (QACs) are cationic surfactants used as preservatives and environmental disinfectants. Limited data are available regarding the effect of QACs in the clinical setting. We performed a prospective cohort study in 153 patients with Escherichia coli bacteraemia from February to September 2008 at University Hospital in Rennes. The minimum inhibitory concentrations (MICs) of antibiotics and QACs alkyldimethylbenzylammonium chloride (ADBAC) and didecyldimethylammonium chloride (DDAC) were determined by the agar dilution method. The capacity of biofilm production was assayed using the Crystal Violet method, and mutation frequencies by measuring the capacity of strains to generate resistance to rifampicin. Logistic regression analysis showed that one of the significant factors related to low MICs for ADBAC (≤16 mg/L) and DDAC (≤8 mg/L), was cotrimoxazole susceptibility (odds ratio: 3.72; 95% confidence interval: 1.22-11.24; P=0.02 and OR: 3.61; 95% CI: 1.56-7.56; P<0.01, respectively). Antibiotic susceptibility to cotrimoxazole was strongly associated with susceptibility to amoxicillin and nalidixic acid (P<0.01). Community-acquired or healthcare-associated bacteraemia, severity of bacteraemia, and patient outcome were independent of the MICs of ADBAC and DDAC. Our findings demonstrate an epidemiological relationship between higher MIC values of QACs in clinical E. coli isolates and antibiotic resistance.


Subject(s)
Bacteremia/drug therapy , Escherichia coli/drug effects , Microbial Sensitivity Tests/standards , Quaternary Ammonium Compounds , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteremia/microbiology , Benzalkonium Compounds/administration & dosage , Benzalkonium Compounds/pharmacology , Benzalkonium Compounds/therapeutic use , Biofilms/drug effects , Drug Resistance, Bacterial , Escherichia coli/genetics , Escherichia coli/growth & development , Escherichia coli/isolation & purification , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Female , Humans , Male , Microbial Sensitivity Tests/methods , Middle Aged , Mutation , Prognosis , Quaternary Ammonium Compounds/administration & dosage , Quaternary Ammonium Compounds/pharmacology , Quaternary Ammonium Compounds/therapeutic use , Treatment Outcome
12.
Vet Microbiol ; 137(3-4): 306-12, 2009 Jun 12.
Article in English | MEDLINE | ID: mdl-19201550

ABSTRACT

Hypermutation is an important mechanism used by different Salmonella enterica subspecies enterica to regulate genetic stability in adaptation to changing environments, including antimicrobial treatments and industrial processes. Strong hypermutator strains generally contain a mutation in genes of the methyl mismatch repair (MMR) system and have mutation frequencies up to 1000-fold higher than wild type strains. The objectives of this study were to determine the distribution of mutation frequencies from a collection of 209 Salmonella strains, to genetically characterize a strong mutator, and to study MMR mutated protein-DNA binding interactions. Only one strain of S. Heidelberg was determined to have a hypermutator phenotype by virtue of its high mutation rate. Sequencing of genes of the MMR system showed a 12bp deletion in the mutS gene was present. The MMR mutated protein-DNA binding interactions were studied by bioanalysis, using the available crystal structure of a similar MutS protein from Escherichia coli. This analysis showed the small deletion in the Salmonella MutS was localized within the core domain. A retardation assay with MutS from hypermutable and wild type strains showed this mutation has no effect on MutS DNA binding. A better understanding of the genetic mechanisms of hypermutation will help to anticipate the behavior of hypermutator strains in various conditions.


Subject(s)
Salmonella Infections/microbiology , Salmonella enterica/genetics , Salmonella enterica/metabolism , Animals , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Drug Resistance, Bacterial/genetics , Gene Expression Regulation, Bacterial/physiology , Humans , Mutation , Salmonella enterica/drug effects
13.
J Hosp Infect ; 72(1): 17-22, 2009 May.
Article in English | MEDLINE | ID: mdl-19246120

ABSTRACT

This study describes an outbreak of Serratia marcescens and its investigation and control in a neonatal intensive care unit (NICU). During a three-month period, five infants were colonised or infected by a single strain of S. marcescens. A case-control study, culture surveys and pulse-field gel electrophoresis analysis implicated a bottle soap dispenser as a reservoir of S. marcescens (P=0.032). Infants with S. marcescens colonisation or infection were also more likely to have been exposed to a central or percutaneous venous catheter (P=0.05) and had had longer exposure to endotracheal intubation (P=0.05). Soap dispensers are used in many hospitals and may be an unrecognised source of nosocomial infections. This potential source of infection could be reduced by using 'airless' dispensers which have no air intake for the distribution of soap. Prompt intervention and strict adherence to alcoholic hand disinfection were the key factors that led to the successful control of this outbreak.


Subject(s)
Cross Infection/epidemiology , Disease Outbreaks , Environmental Microbiology , Serratia Infections/epidemiology , Serratia marcescens/isolation & purification , Soaps , Bacterial Typing Techniques , Case-Control Studies , Cross Infection/microbiology , DNA Fingerprinting , DNA, Bacterial/genetics , Electrophoresis, Gel, Pulsed-Field , Female , Genotype , Hand Disinfection/methods , Humans , Infant, Newborn , Infection Control/methods , Intensive Care Units, Neonatal , Male , Risk Factors , Serratia Infections/microbiology , Serratia marcescens/classification , Serratia marcescens/genetics
14.
Acta Paediatr ; 97(10): 1381-5, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18782359

ABSTRACT

OBJECTIVE: To describe an outbreak of Serratia marcescens infections in a neonatal intensive care unit (NICU) and to report investigations and interventions having led to the cessation of the outbreak. DESIGN: Observational study of microbiological and epidemiological investigations realised during a S. marcescens outbreak between March and October 2006. METHODS: Nine cases were observed in a 5 months period. A Serratia outbreak was therefore identified, and all the strains were compared by pulsed-field gel electrophoresis (PFGE). Data from medical notes were gathered retrospectively. Environmental samples were gathered prospectively. RESULTS: Four infants were colonized and five infants were infected by S. marcescens. PFGE revealed that three different strains were present. Seven of the nine babies were infected by only one of these strains. This same strain was found in a nonantimicrobial soap bottle (NAS) that could be the source of contamination. CONCLUSION: It is the first time that S. marcescens is found in a NAS during a neonatal nosocomial outbreak. Molecular analysis is a method of choice to compare different strains. Identification and elimination of the nosocomial source and adherence to the infection control policies are essential to succeed in the containment of a nosocomial epidemic.


Subject(s)
Cross Infection/epidemiology , Disease Outbreaks , Hand Disinfection , Serratia Infections/epidemiology , Serratia marcescens/isolation & purification , Soaps , Cross Infection/microbiology , Electrophoresis, Gel, Pulsed-Field , Female , France/epidemiology , Humans , Infant, Newborn , Infection Control , Intensive Care Units, Neonatal/statistics & numerical data , Male , Retrospective Studies , Risk Factors , Serratia Infections/etiology , Serratia Infections/microbiology
15.
Int J Food Microbiol ; 112(2): 147-52, 2006 Nov 01.
Article in English | MEDLINE | ID: mdl-16876276

ABSTRACT

S. Typhimurium LT2 cells suspended in sterilized sewage effluent water (SEW) and in distilled water microcosms were exposed to 0, 7, 15 and 20 mg/l peracetic acid, and tested for viability and virulence. After treatment for one hour, colony forming units decreased by at least 5 log units at peracetic acid concentration of 7 mg/l. In SEW, at peracetic acid concentration of 15 mg/l, the cells were nonculturable (VNC), but retained virulence as demonstrated by invasion assays of HeLa cells. Higher concentrations (greater than or equal to 20 mg/l) resulted in bacterial death, i.e. substrate non-responsive cells. Despite morphological alterations of the bacteria after peracetic acid treatment, visualized by transmission electronic microscopy, conservation of both adhesive and invasive capacities was confirmed by scanning electron microscopy after exposure to 0-15 mg/l peracetic acid. Public health professionals need to recognize that peracetic acid-treated Salmonella is capable of modifying its physiological characteristics, including entering and recovering from the viable but nonculturable state, and may remain virulent after a stay in SEW followed by peracetic acid treatment.


Subject(s)
Disinfectants/pharmacology , Peracetic Acid/pharmacology , Salmonella typhimurium/physiology , Salmonella typhimurium/pathogenicity , Adaptation, Physiological , Bacterial Adhesion/drug effects , Bacterial Adhesion/physiology , Colony Count, Microbial , Dose-Response Relationship, Drug , HeLa Cells/microbiology , Humans , Microscopy, Electron, Scanning , Salmonella typhimurium/drug effects , Salmonella typhimurium/ultrastructure , Sewage/microbiology , Virulence , Water Microbiology
16.
Int J Paediatr Dent ; 16(2): 75-80, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16430520

ABSTRACT

OBJECTIVES: (i) To compare the prevalence and levels of Capnocytophaga, a known systemic pathogen in immunocompromised patients, in the dental plaque of healthy children and children with cancer, and (ii) to determine the susceptibility of strains isolated from cancer patients to a range of antibiotics. PATIENTS AND METHODS: Thirty-one children with cancer undergoing a first course of immunosuppressive chemotherapy and 30 healthy control children were included in the study. Samples were collected on days 0, 7, 14, and 21 of the cure (and equivalent dates in controls). Susceptibility to antibiotics was tested using an agar dilution method and galleries with predefined concentrations of selected antibiotics. RESULTS: There was a significant drop in the total anaerobic cultivable flora on day 14 and in the prevalence of Capnocytophaga on days 14 and 21 in the children with cancer. The proportion of Capnocytophaga in the anaerobic flora, however, was high in certain cancer patients. Beta-lactam/beta-lactamase inhibitor combinations, imipenem, clindamycin, and tetracycline were the most effective against Capnocytophaga. CONCLUSION: This study showed that Capnocytophaga decreased in prevalence and proportion in the dental plaque of cancer patients during chemotherapy but became predominant in some cases. It is recommended that imipenem or beta-lactam/beta-lactamase inhibitor combinations be used to treat Capnocytophaga bacteraemia.


Subject(s)
Capnocytophaga/drug effects , Dental Plaque/microbiology , Immunocompromised Host , Leukemia, Myeloid, Acute/drug therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Adolescent , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Anti-Infective Agents/pharmacology , Anti-Infective Agents/therapeutic use , Capnocytophaga/isolation & purification , Case-Control Studies , Chi-Square Distribution , Child , Child, Preschool , Colony Count, Microbial , Drug Resistance , Female , Humans , Lymphoma/drug therapy , Male , Microbial Sensitivity Tests , Statistics, Nonparametric , Trimethoprim, Sulfamethoxazole Drug Combination/pharmacology , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use
17.
Cell Biol Toxicol ; 19(2): 83-93, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12776926

ABSTRACT

The influence of peracetic acid (PAA) disinfectant on Salmonella enterica serotype Typhimurium LT2 in sewage effluent was examined by studying its ability to adhere to and invade HeLa cells in vitro. Although the disinfectant produced a decrease of about 5 log units, the bacteria kept their adhesive and invasive abilities. Scanning microscopic observations of the PAA-treated bacteria revealed that PAA caused a loss of external microfilaments and an alteration of membrane structure. Nevertheless, electron-microscopic observations showed that PAA-treated bacteria were still able to adhere to and invade HeLa cells despite the fact that the bacteria seemed to have undergone some structural modifications. With confocal microscopy, the use of anti-actin antibody showed that the contact between the bacteria (with or without PAA treatment) and the HeLa cells activated actinopolymerization of the HeLa cell cytoskeleton.


Subject(s)
Bacterial Adhesion/drug effects , Disinfectants/toxicity , Peracetic Acid/toxicity , Salmonella typhimurium/pathogenicity , Cell Membrane/microbiology , Cell Membrane/ultrastructure , HeLa Cells , Humans , Intracellular Space/microbiology , Intracellular Space/ultrastructure , Salmonella typhimurium/drug effects , Salmonella typhimurium/ultrastructure , Sewage
18.
Appl Environ Microbiol ; 66(12): 5484-7, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11097933

ABSTRACT

Randomly amplified polymorphic DNA (RAPD) analysis is a DNA polymorphism assay commonly used for fingerprinting genomes. After optimizing the reaction conditions, samples of Escherichia coli H10407 DNA were assayed to determine the influence of osmotic and/or oligotrophic stress on variations in RAPD banding patterns. Genetic rearrangements or DNA topology variations could be detected as changes in agarose gel electrophoresis banding profiles. A new amplicon generated using DNA extracted from bacteria prestarved by an osmotic stress and resuscitated in rich medium was observed. Enrichment improved recovery of mutator cells and allowed them to be detected in samples, suggesting that DNA modifications, such as stress-induced alterations and supercoiling phenomena, should be taken into consideration before beginning RAPD analyses.


Subject(s)
DNA, Bacterial/genetics , Escherichia coli/genetics , Gene Rearrangement , Genes, Bacterial , Base Sequence , DNA Fingerprinting , DNA Primers/genetics , Genetic Variation , Osmotic Pressure , Phenotype , Random Amplified Polymorphic DNA Technique
19.
Antimicrob Agents Chemother ; 44(11): 3186-8, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11036049

ABSTRACT

The susceptibilities of 43 pharyngeal isolates of Capnocytophaga to beta-lactam antibiotics, alone or in combination with beta-lactamase inhibitors, were tested by an agar dilution method. The 34 beta-lactamase-positive strains were highly resistant to beta-lactams, but the intrinsic activities of clavulanate, tazobactam, and sulbactam against Capnocytophaga, even beta-lactamase producers, indicates that these beta-lactamase inhibitors could be used for empirical treatment of neutropenic patients with oral sources of infection.


Subject(s)
Anti-Bacterial Agents/pharmacology , Capnocytophaga/drug effects , Penicillanic Acid/analogs & derivatives , beta-Lactamase Inhibitors , Anti-Bacterial Agents/therapeutic use , Capnocytophaga/enzymology , Clavulanic Acid/pharmacology , Clavulanic Acid/therapeutic use , Gram-Negative Bacterial Infections/microbiology , Humans , Microbial Sensitivity Tests , Penicillanic Acid/pharmacology , Penicillanic Acid/therapeutic use , Tazobactam , beta-Lactam Resistance
20.
Microbios ; 90(364-365): 209-18, 1997.
Article in English | MEDLINE | ID: mdl-9418038

ABSTRACT

Strains of Klebsiella oxytoca (2), Citrobacter freundii (2), Enterobacter cloacae (1) and Escherichia coli (1) isolated from environmental water were identified as heat-labile enterotoxin (LT) producing strains by immunological methods and polymerase chain amplification. A 322 bp amplified fragment was obtained with specific primers LTR and LTL, and hybridized to a digoxigenin-labelled LTB probe only under low stringency conditions, and not with a cholera toxin probe. These results suggest that Enterobacteriaceae may produce a LT-like toxin antigenically and genetically related to the LT enterotoxin of E. coli.


Subject(s)
Bacterial Toxins/biosynthesis , Enterobacteriaceae/pathogenicity , Enterotoxins/biosynthesis , Escherichia coli Proteins , Escherichia coli/pathogenicity , Water Microbiology , Bacterial Toxins/genetics , Enterotoxins/genetics , Polymerase Chain Reaction
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