The Streptococcus agalactiae Exonuclease ExoVII Is Required for Resistance to Exogenous DNA-Damaging Agents.

Streptococcus agalactiae is a human pathogen responsible for severe invasive infections in newborns. In this bacterium, XseB, a part of the ExoVII exonuclease, was shown to be specifically more abundant in the hypervirulent ST-17 strains. In Escherichia coli, ExoVII is associated either with mismatch repair or with recombinational DNA repair and is redundant with other exonucleases. In this study, the biological role of S. agalactiae ExoVII was examined. The ΔexoVII mutant strain was subjected to different DNA-damaging agents, as well as a large set of mutants impaired either in the mismatch repair pathway or in processes of recombinational DNA repair. Our results clarified the role of this protein in Gram-positive bacteria as we showed that ExoVII is not significantly involved in mismatch repair but is involved in bacterial recovery after exposure to exogenous DNA-damaging agents such as ciprofloxacin, UV irradiation, or hydrogen peroxide. We found that ExoVII is more particularly important for resistance to ciprofloxacin, likely as part of the RecF DNA repair pathway. Depending on the tested agent, ExoVII appeared to be fully redundant or nonredundant with another exonuclease, RecJ. The importance of each exonuclease, ExoVII or RecJ, in the process of DNA repair is thus dependent on the considered DNA lesion. IMPORTANCE This study examined the role of the ExoVII exonuclease of Streptococcus agalactiae within the different DNA repair processes. Our results concluded that ExoVII is involved in bacterial recovery after exposure to different exogenous DNA-damaging agents but not in the mismatch repair pathway. We found that ExoVII is particularly important for resistance to ciprofloxacin, likely as part of the RecF DNA repair pathway.

[Hypersensitivity pneumonitis and abscess reaction to nontuberculous mycobacteria acquired form jacuzzi aerosol]. / Pneumopathie d'hypersensibilité à mycobactéries atypiques se compliquant d'un abcès à Mycobacterium intracellulare.

INTRODUCTION: Mycobacterium avium complex can be responsible for a number of different radio-clinical presentations, ranging from invasive infections to hypersensitivity pneumonitis due to repeated inhalation of antigens. The diagnosis of hypersensitivity pneumonitis is clinical, radiological, biological and microbiological. CASE REPORT: A 61-year-old male developed a hypersensitivity pneumonitis reaction to non-tuberculous mycobacteria, following the repeated use of his own spa, which later evolved into chronic respiratory failure. The diagnosis was made via an environmental analysis. Immunosuppressive treatment comprising corticosteroids and methotrexate led to moderate improvement, but may also have been responsible for the development of a M. intracellulare abscess. Despite 12 months of well-conducted antibiotic treatment, the evolution was unfavourable, with a relapse of a M. intracellulare infection three months after the end of treatment, followed by the patient's death. CONCLUSION: Hypersensitivity pneumonitis reaction to non-tuberculous mycobacteria should be considered in patients who have their own spa. In the absence of microbiological identification, environmental analysis may guide the diagnosis. A fatal evolution of PHS is infrequent but prognosis may depend on the degree of associated fibrosis.

Detection of Bartonella in cat scratch disease using a single-step PCR assay kit.

PURPOSE: Bartonella is an increasingly isolated emerging pathogen that can cause severe illness in humans, including cat scratch disease (CSD). The bacteria are difficult to grow and thus many detection methods have been developed, especially molecular. We previously developed a PCR method targeting ribC to identify Bartonella sp. A manufactured kit (RealCycler BART, Progenie Molecular) was commercialised shortly thereafter for the detection of Bartonella infection, including Bartonella henselae. METHODOLOGY: We performed a comparison between this test and our in-house PCR assay on 73 lymphadenopathy samples sent to the laboratory for suspicion of CSD.Results/Key findings. Among the 28 positive samples for Bartonella, 21 were identified by the two PCR assays, and seven by the commercial kit only. CONCLUSION: The performance of this commercial kit suggests that it could be a suitable alternative to our in-house PCR assay, highlighting the importance of the molecular methods used to diagnose CSD.

Inventory of Extended-Spectrum-ß-Lactamase-Producing Enterobacteriaceae in France as Assessed by a Multicenter Study.

The objective of this study was to perform an inventory of the extended-spectrum-ß-lactamase (ESBL)-producing Enterobacteriaceae isolates responsible for infections in French hospitals and to assess the mechanisms associated with ESBL diffusion. A total of 200 nonredundant ESBL-producing Enterobacteriaceae strains isolated from clinical samples were collected during a multicenter study performed in 18 representative French hospitals. Antibiotic resistance genes were identified by PCR and sequencing experiments. The clonal relatedness between isolates was investigated by the use of the DiversiLab system. ESBL-encoding plasmids were compared by PCR-based replicon typing and plasmid multilocus sequence typing. CTX-M-15, CTX-M-1, CTX-M-14, and SHV-12 were the most prevalent ESBLs (8% to 46.5%). The three CTX-M-type EBSLs were significantly observed in Escherichia coli (37.1%, 24.2%, and 21.8%, respectively), and CTX-M-15 was the predominant ESBL in Klebsiella pneumoniae (81.1%). SHV-12 was associated with ESBL-encoding Enterobacter cloacae strains (37.9%). qnrB, aac(6')-Ib-cr, and aac(3)-II genes were the main plasmid-mediated resistance genes, with prevalences ranging between 19.5% and 45% according to the ESBL results. Molecular typing did not identify wide clonal diffusion. Plasmid analysis suggested the diffusion of low numbers of ESBL-encoding plasmids, especially in K. pneumoniae and E. cloacae However, the ESBL-encoding genes were observed in different plasmid replicons according to the bacterial species. The prevalences of ESBL subtypes differ according to the Enterobacteriaceae species. Plasmid spread is a key determinant of this epidemiology, and the link observed between the ESBL-encoding plasmids and the bacterial host explains the differences observed in the Enterobacteriaceae species.

[Bacterial flora in blepharitis]. / La flore bactérienne dans les blépharites.

INTRODUCTION: Blepharitis has multiple, poorly defined origins. The goal of this study was to investigate the bacterial flora present in patients affected with blepharitis in comparison with healthy subjects, so as to understand the role of bacterial etiologies in blepharitis. MATERIALS AND METHODS: Fifty-four patients with blepharitis and 50 healthy controls participated in this study. Swabs were obtained and analyzed qualitatively and quantitatively for bacteria. A subgroup of 16 people (9 with blepharitis and 7 controls) also were investigated for Demodex. RESULTS: The percentages of the positive cultures and the number of colonies/case were clearly higher for patients with blepharitis in comparison with healthy controls. Bacteria were isolated for 81% of cases versus 38% for controls, with a mean of 39 colonies versus 4.4 colonies for controls. Corynebacterium sp. were the most common microorganisms isolated from patients with blepharitis (53.7% for cases versus 18% for controls, P<0.01), and the bacterial load was 15 times higher (37.4 col/case versus 2.6 col/case). C. macginleyi was the most common Corynebacteria (33% versus 6%, P<0.01). S. epidermidis: 35.1% versus 16% (P=0.02) with 11.3 col/case versus 1.6 col/case. S. aureus: 13% versus 0% (P=0.01) with 24.7 col/case versus 0. We did not find a significant difference for Propionibacterium acnes: 14.8% versus 14% with 4.7 col/case versus 5.1 col/case, or for Demodex, with 22.2% versus 28.6%. CONCLUSION: Corynebacterium sp. and especially C. macginleyi seem to participate actively in the physiopathology of blepharitis. S. epidermidis and S. aureus also remain associated with this pathology.

[Emerging uropathogens: Point for urologists and biologists]. / Mise au point : les uropathogènes émergents.

INTRODUCTION: Technological advances during the last years in bacterial identification by molecular biology and mass spectrometry, or Matrix Assisted Laser Desorption Ionisation-Time of Flight (MALDI-TOF) have allowed identifying new bacteria involved in urinary tract infections. The purpose of this review is to familiarize clinicians with these bacteria so that they can look at a particular target population and help biologists to suspect and identify them. METHOD: A bibliographic research was performed using the Medline database concerning the keywords Aerococcus, Actinobaculum, Alloscardovia, Trueperella. RESULTS: If Aerococcus sp. is now well known, Actinobaculum sp., Alloscardovia sp. and Trueperella sp. remain rarely isolated and unknown from clinicians. Importance of these germs could be underestimated because of the identifying and isolation difficulties which existed beforehand. They are particularly found in a population of elderly people with underlying conditions or urological risk factors of urinary tract infection. Actinobaculum schaalii is also found more frequently in young children. CONCLUSION: Aerococcus sp. et A. schaalii are true uropathogens not to be underestimated. Further studies are still needed to confirm the specific involvement of Trueperella and Alloscardovia in urinary diseases.

Decline in antibiotic resistance and changes in the serotype distribution of Streptococcus pneumoniae isolates from children with acute otitis media; a 2001-2011 survey by the French Pneumococcal Network.

Streptococcus pneumoniae is an important cause of acute otitis media (AOM). The aim of this study was to evaluate trends in antibiotic resistance and circulating serotypes of pneumococci isolated from middle ear fluid of French children with AOM during the period 2001-2011, before and after the introduction of the PCV-7 (2003) and PCV-13 (2010) vaccines. Between 2001 and 2011 the French pneumococcal surveillance network analysed the antibiotic susceptibility of 6683 S. pneumoniae isolated from children with AOM, of which 1569 were serotyped. We observed a significant overall increase in antibiotic susceptibility. Respective resistance (I+R) rates in 2001 and 2011 were 76.9% and 57.3% for penicillin, 43.0% and 29.8% for amoxicillin, and 28.6% and 13.0% for cefotaxime. We also found a marked reduction in vaccine serotypes after PCV-7 implementation, from 63.0% in 2001 to 13.2% in 2011, while the incidence of the additional six serotypes included in PCV-13 increased during the same period, with a particularly high proportion of 19A isolates. The proportion of some non-PCV-13 serotypes also increased between 2001 and 2011, especially 15A and 23A. Before PCV-7 implementation, most (70.8%) penicillin non-susceptible pneumococci belonged to PCV-7 serotypes, whereas in 2011, 56.8% of penicillin non-susceptible pneumococci belonged to serotype 19A. Between 2001 and 2011, antibiotic resistance among pneumococci responsible for AOM in France fell markedly, and PCV-7 serotypes were replaced by non-PCV-7 serotypes, especially 19A. We are continuing to assess the impact of PCV-13, introduced in France in 2010, on pneumococcal serotype circulation and antibiotic resistance.

Life-threatening Escherichia coli cellulitis in patients with haematological malignancies.

Cellulitis due to Escherichia coli is rare and usually secondary to a cutaneous portal of entry. Skin and soft tissue infections (SSTI) secondary to E. coli bacteraemia have been reported exclusively in immunodeficient patients. Here, we report two cases of serious cellulitis secondary to E. coli bacteraemia in patients with haematological malignancies. Both isolated strains belonged to phylogenetic group B2 and harboured some of the main virulence factor genes commonly found in extra-intestinal pathogenic E. coli (ExPEC), including neuC, iro and fimH. Cellulitis due to E. coli seems to be linked to the immunocompromised status of patients rather than to a highly virulent clone. Nevertheless, some of the virulence factors appear to be important because both isolates belong to phylogenetic group B2. This aetiology should be considered in SSTI in patients with haematological malignancies.

[Tropical pneumonia: pulmonary melioidosis]. / Une pneumonie exotique à ne pas méconnaitre : la mélioïdose pulmonaire.

Melioidosis is a disease that is endemic in North Australia and Southeast Asia, caused by Burkholderia pseudomallei. This Gram-negative organism can affect all organs, but presents most commonly as severe pneumonia. We report a 58-year-old man who presented with a B. pseudomallei pneumonia on his return from Thailand. Radiography revealed a complete disappearance of symptoms after a 3-week therapy with ceftazidime and doxycycline followed by 4 months of combined amoxicillin-clavulanic acid and doxycycline therapy. No relapse had occurred 18 months later.

[1997-2007, 10 years of monitoring the evolution of resistance of Streptococcus pneumoniae to antibiotics in the region Centre; review of the Pneumococcus network]. / 1997-2007, dix ans de suivi de l'évolution de la résistance de Streptococcus pneumoniae aux antibiotiques en région Centre; bilan de l'observatoire du pneumocoque.

Regional pneumococcal observatories in region Centre, created in 1997, participate with the others pneumococcal observatories alongside the National Reference Center for Pneumococci and the Institut de Veille Sanitaire at the monitoring of the evolution of resistance of pneumococci to antibiotics in France. Between 1997 and 2007, 2427 strains of Streptococcus pneumoniae were isolated in part from cerebrospinal fluids, blood and middle ear fluid, from children and adults. The prevalence of pneumococci with a decreased susceptibility to penicillin (PDSP) decreased strongly in region Centre: 56.8 % in 2001, 39.6 % en 2007. These data are similar to the French national data over the same period.

[PCR rDNA 16S used for the etiological diagnosis of blood culture negative endocarditis]. / PCR rDNA 16S dans le diagnostic étiologique des endocardites infectieuses à hémocultures négatives.

We report the case of a 55 year-old man presenting with a double aortic and mitral endocarditis for which resected valve culture was repeatedly negative. Specific PCR made on valves because of highly positive blood tests for Bartonella henselae remained negative. A molecular approach was made with 16S rDNA PCR, followed by sequencing. Bartonella quintana was identified as the etiology of endocarditis. B. quintana, "fastidious" bacteria, even if hard to identify in a laboratory, is often reported as a blood culture negative endocarditis (BCNE) agent. Molecular biology methods have strongly improved the diagnosis of BCNE. We propose a review of the literature focusing on the interest of broad-spectrum PCR on valve for the etiological diagnosis of BCNE.

[Prevalence of extended-spectrum beta-lactamases of the CTX-M type producing Escherichia coli and Klebsiella pneumoniae in Bretonneau hospitals (CHRU Tours)]. / Prévalence des souches de Escherichia coli et de Klebsiella pneumoniae productrices de beta-lactamases à spectre étendu de type CTX-M à l'hôpital Bretonneau (CHRU de Tours).

The CTX-M type extended spectrum beta-lactamases constitute a rapidly growing cluster of enzymes that have disseminated geographically. This study evaluates the prevalence of these enzymes in the university hospital in Tours, in 2007. Twenty-eight strains were studied: 21 Escherichia coli and seven Klebsiella pneumoniae. The gene bla(CTX-M) was detected by real-time PCR for 27 strains. The CTX-M-1 group, including CTX-M-15, was the most frequent CTX-M-type enzyme.

[Acute mastoiditis in children: can mastoidectomy be avoided?]. / Mastoïdite aiguë extériorisée chez l'enfant: la mastoïdectomie peut-elle être évitée?

OBJECTIVE: Mastoidectomy is the standard management for exteriorized mastoiditis. The objective of this study was to assess the results of conservative management of acute mastoiditis and to study the types of bacteria isolated and their sensitivity to antibiotics. METHODS: A retrospective study including children admitted with acute mastoiditis was conducted between 1994 and 2007. Intravenous antibiotics were systematic. Since 2002, mastoidectomy has been replaced by retroauricular puncture and grommet tube insertion. RESULTS: Forty-four children had acute mastoiditis. All but one (temporozygomatic swelling) had postauricular swelling. The culture was positive in 78% of cases. Streptococcus pneumoniae was the most common bacteria identified. Twenty-six subperiosteal abscesses were found on the CT scan. Mastoidectomy was performed in 17 cases, 16 of which took place before 2002. The hospital stay has been decreased by six days with retroauricular puncture and grommet tube insertion management. CONCLUSION: In the absence of intracranial complications and suspicion of Fusobacterium necrophorum, a retroauricular puncture and grommet tube insertion associated with antibiotic therapy is an effective alternative to mastoidectomy in the treatment of acute mastoiditis with subperiosteal abscess.

Human-to-human transmission of tuberculosis caused by Mycobacterium bovis in immunocompetent patients.

Human-to-human transmission of Mycobacterium bovis in two immunocompetent patients from the same family was confirmed by spoligotyping (pattern F35, which was only observed in cattle from the same area in France). A single allelic difference between animal and human isolates was observed with mycobacterial interspersed repetitive units containing variable-number tandem repeats, suggesting a jump across the species barrier.

[Pediatric osteoarticular infections caused by Kingella kingae from 1995 to 2006 at CHRU de Tours]. / Infections ostéo-articulaires pédiatriques à Kingella kingae de 1995 à 2006 au CHRU de Tours.

Use of molecular biology shows that Kingella kingae is a pathogen frequently involved in osteoarticular infections in young children. This study describes the cases of osteoarticular infections due to K. kingae which happened from 1995 to 2006 in the CHRU of Tours. The description is based on clinical and biological features. A K. kingae specific polymerase chain reaction was performed in our laboratory in order to improve K. kingae osteoarticular infections diagnosis, and is detailed here.

[Rectal prolapse in a 3-year-8-month-old child]. / Prolapsus rectal chez un enfant de 3 ans 8 mois.

INTRODUCTION: Starting from a recent clinical case, we present the different causes of rectal prolapse and their specific treatments. In this case, the relation to infectious colitis was questionable. OBSERVATION: This 3-year-8-month-old boy had repetitive rectal prolapses with phlegmy and bloody diarrhea, with reduction increasingly difficult. Stool analysis was negative but pseudomembranous colitis was found with coloscopy and was confirmed by biopsy. DISCUSSION: Hygienic and dietary measures are the first steps in the treatment rectal prolapse. Pseudomembranous colitis, often related to Clostridium difficile toxins; is a severe form of postantibiotic diarrhea. Its treatment is based on oral antibiotic therapy with metronidazole or vancomycin for 10 days. Rectal prolapsus in children is cured without recurrence in 98% of cases. CONCLUSION: In the case reported herein, rectal prolapse did not recur after diarrhea recovery with antibiotic therapy, suggesting a causative link with pseudomembranous colitis.

Application of the French guidelines for preventing neonatal group B streptococcal disease in a university hospital.

This study evaluated the application of the French guidelines for prevention of neonatal group B streptococcus (GBS) infections. The prevalence of GBS vaginal carriage by pregnant women during the study period was 6%. Less than 50% of pregnant women testing positive for GBS were treated with at least two doses of antibiotics during labour, and most received only one dose or no antibiotics. In addition, several neonates were colonised or infected by GBS although their mothers were GBS-negative. These results are consistent with vaginal screening having a poor sensitivity, as suggested by the low prevalence of GBS carriage.

[Molecular identification of species within the Mycobacterium tuberculosis complex using regions of difference]. / Identification moléculaire des espèces de mycobactéries du groupe de la tuberculose par étude des régions de différence.

The differentiation within the Mycobacterium tuberculosis complex (MTBC) based on phenotypic methods is long and does not give an unambiguous result in every case whereas the advance in genetic knowledge leads to new views. Thus, regions of difference (RD), that seem to characterize the species of the MTBC, have been identified. Amplification methods, targeted on these zones, have been developed then. The study of four regions (RD1, RD5, RD9, RD10) has been done on 64 isolates formerly identified thanks to phenotypic methods. Genotypic results confirm phenotypic identifications except in one case. This strain initially identified as M. tuberculosis and isolated from a Gabonese patient, corresponds, according to genotypic identification, to M. africanum. Since phenotypic characterization of M. africanum is difficult, this method would allow to accurately determine the true prevalence of this specie. Moreover, the study of RD10 doesn't seem to be informative. The amplification of only two RD, RD1 and RD9 carries out the identification of all M. tuberculosis and M. bovis BCG isolates. M. bovis and M. africanum will be then identified thanks to RD5. Thus, this easy and rapid method of identification of the major species of MTBC seems to be appropriated for a routine use.