Early symptomatic neurosyphilis and ocular syphilis: A comparative study between HIV-positive and HIV-negative patients.

OBJECTIVES: Since the 2000s, there has been an increase in prevalence of neurosyphilis (NS) and ocular syphilis (OS). As data about symptomatic NS/OS is limited, this study aims to assess the characteristics of symptomatic NS/OS, according to HIV status. METHODS: We compared the clinical and biological presentation of early symptomatic NS/OS and its outcome in HIV-positive and HIV-negative patients. RESULTS: Ninety-six patients (93% men, 49% HIV-positive) were included from 2000 to 2016 in two centers, with 67 (69%) having OS, 15 (16%) NS, and 14 (14%) both. HIV-positive patients were younger (P=0.006) and more likely to be males having sex with males (P=0.00048) or to have a history of syphilis (P=0.01). Among 81 OS, there were 43 posterior uveitis (57%), and bilateral involvement was more common in HIV-positive patients (62% versus 38%, P=0.045). Among 29 NS there were 21 cases of cranial nerve involvement (72%), seven meningitis (24%) and 11 paresthesia (38%). Involvement of the VIIIth cranial nerve was the most common (16 cases). Treponemal tests were more commonly found positive in cerebrospinal fluid in HIV-positive patients (88% versus 76%, P=0.04). Visual acuity (VA) always improved after treatment (initial VA logMAR 0.8±0.8 versus 0.1±0.1 at 3 months), but 32% and 18% of the patients still had neurological or ocular impairment respectively six and 12 months after treatment. Non-treponemal serological reversion was observed in 43/50 patients (88%) at six months. CONCLUSION: HIV infection has no consequence on the outcome of NS and OS. Sequelae are common, emphasizing the importance of prevention, and screening, and questioning enhanced treatment.

Area of technical uncertainty for susceptibility testing of amoxicillin/clavulanate against Escherichia coli: analysis of automated system, Etest and disk diffusion methods compared to the broth microdilution reference.

OBJECTIVES: The European Committee on Antimicrobial Susceptibility Testing (EUCAST) recently warned about an area of technical uncertainty (ATU) of amoxicillin/clavulanate (AMX/C) disk susceptibility testing against members of the Enterobacterales. Thus, we aimed to compare the reliability of three routine methods and to evaluate the impact of the ATU. METHODS: 286 Escherichia coli strains (including 159 AMX-resistant strains) were categorized for the two EUCAST AMX/C breakpoints by disk diffusion (Bio-Rad), the Phoenix automated system (Becton Dickinson) and the Etest (AES) compared to the broth microdilution reference method. RESULTS: By microdilution, 84.2% of strains were AMX/C-susceptible using the urinary breakpoint (MIC ≤32 mg/L) and 62.2% using the systemic breakpoint (MIC ≤8 mg/L), with 63.6% of MICs between 4 and 16 mg/L. For the systemic breakpoint, category agreement (CA) and very major error (VME) were unacceptable for the Etest (71.7% and 27.3%), disk (73.1% and 23.4% at 19-mm cut-off) and to a lesser extent for the Phoenix system (83.6% and 10.5%). For disks, an unacceptable VME rate was observed for diameters up to 22 mm, probably due to overcharged disks. For the Etest, VMEs were high at 6 mg/L (46/63) and 8 mg/L (22/29). For the urinary breakpoint, CA was more acceptable for disk (88.9%) and Etest (84.3%) but was unevaluable for Phoenix. CONCLUSION: AMX/C susceptibility testing of E. coli for systemic breakpoint was unreliable with the three routine methods, explained mainly by the high prevalence (~60%) of strains with microdilution MICs around the breakpoint (8 mg/L). Our data confirmed the EUCAST 19-20-mm ATU for disk and suggest introducing ATU for Etest MIC values of 6 and 8 mg/L.

Temocillin against Enterobacteriaceae isolates from community-acquired urinary tract infections: low rate of resistance and good accuracy of routine susceptibility testing methods.

Background: Temocillin is an old 'revived' antibiotic that may play an important role in the treatment of febrile urinary tract infection (UTI). Data regarding its activity against current Enterobacteriaceae isolates as well as the performance of routine susceptibility testing methods are, however, scarce. Objectives: To determine the MICs of temocillin for Enterobacteriaceae strains reflecting the current epidemiology and to analyse the accuracy of three commercial methods. Methods: Enterobacteriaceae isolates causing community-acquired UTI were prospectively collected from September 2015 to January 2017 in two French centres. Temocillin MIC was determined by agar dilution (AD) as the reference method and then compared with: (i) susceptibility testing by disc diffusion; (ii) MIC determination by Etest; and (iii) MIC estimation by the Vitek 2 automated system. Results: A total of 762 Enterobacteriaceae were analysed comprising 658 (86.4%) Escherichia coli and 37 (4.9%) ESBL-producing isolates. Susceptibility rate assessed by AD was 99.6% according to the 8 mg/L clinical breakpoint and was significantly lower against the ESBL-producing isolates than the non-ESBL-producing isolates (94.6% versus 99.9%, P < 0.01). The MIC50 and MIC90 for the total set were 3 and 6 mg/L, respectively. According to the 8 mg/L clinical breakpoint, the major error rate was <1% for disc diffusion and Etest, and significantly higher for Vitek 2 (4.3%, P < 0.01), but still low. No very major error was noticed. Conclusions: Temocillin showed a high level of activity against Enterobacteriaceae from community-acquired UTI and good to excellent reliability of routine methods for susceptibility testing in such a setting.

[Description and role of bacteriological techniques in the management of lung infections]. / Description et place des techniques bactériologiques dans la prise en charge des infections pulmonaires.

Acute pneumonias occur in a variety of clinical settings and accurate identification of bacterial causes is extremely important. No microbiological tool is either 100 % sensitive or 100 % specific, and despite investigations, aetiology remains unanswered in more than 30 % of pneumonia. No sample may be necessary for patients treated as outpatients, non invasive respiratory specimens are preferred in hospitalised individuals (community or healthcare associated), while invasive specimens are used as second line for community acquired pneumonia (CAP) in intensive care, and in the first line where pneumonia occurs in immunosuppressed patients. Bacterial cultures have an important place, if the sample is taken before the introduction of antibiotic therapy. Some contexts may justify the use of blood cultures, testing for urinary antigens or serology. PCR is already becoming available as a daily service but the short-term future probably belongs to molecular multiplex panels capable of detecting many microorganisms within hours, especially in severe CAP resuscitation and in pneumonia in the immunosuppressed. High-throughput sequencing nucleotide techniques will soon revolutionize microbiological diagnosis in respiratory medicine, as in other areas of infectious diseases.

A penicillin- and metronidazole-resistant Clostridium botulinum strain responsible for an infant botulism case.

The clinical course of a case of infant botulism was characterized by several relapses despite therapy with amoxicillin and metronidazole. Botulism was confirmed by identification of botulinum toxin and Clostridium botulinum in stools. A C. botulinum A2 strain resistant to penicillins and with heterogeneous resistance to metronidazole was isolated from stool samples up to 110 days after onset. Antibiotic susceptibility was tested by disc agar diffusion and MICs were determined by Etest. Whole genome sequencing allowed detection of a gene cluster composed of blaCBP for a novel penicillinase, blaI for a regulator, and blaR1 for a membrane-bound penicillin receptor in the chromosome of the C. botulinum isolate. The purified recombinant penicillinase was assayed. Resistance to ß-lactams was in agreement with the kinetic parameters of the enzyme. In addition, the ß-lactamase gene cluster was found in three C. botulinum genomes in databanks and in two of 62 genomes of our collection, all the strains belonging to group I C. botulinum. This is the first report of a C. botulinum isolate resistant to penicillins. This stresses the importance of antibiotic susceptibility testing for adequate therapy of botulism.

High bacterial titers in urine are predictive of abnormal postvoid residual urine in patients with urinary tract infection.

Urine bacterial titers (BTs) are influenced by bacterial and host factors. The impact of an abnormal postvoid residual (PVR) on BT in urine was investigated. A total of 103 inpatients with a urine growing Enterobacteriacae (≥ 10(2) CFU/mL) and a PVR measure were analyzed, mostly female (62%), elderly (mean age: 72 years), with urinary tract infection (25% of asymptomatic bacteriuria) due to Escherichia coli (85%). Fifty-two subjects (56%) had BT ≥ 10(6) CFU/mL; 48 (53%) had a PVR ≤ 100 mL, while 26 (25%) had a PVR >250 mL. PVR increased with BT, and a significant (P<0.0001) threshold was reached for 10(6) CFU/mL: 100mL mean PVR for patients with BT ≤ 10(5) CFU/mL versus 248 mL for patients with BT >10(5) CFU/mL. High PVR and BT were associated with complicated infections, concomitant bacteremia, and delayed apyrexia. Screening for patients with BT ≥ 10(6) CFU/mL is an easy way to identify patients at high risk for acute retention and voiding disorders.

Bacterial ClpB heat-shock protein, an antigen-mimetic of the anorexigenic peptide α-MSH, at the origin of eating disorders.

The molecular mechanisms at the origin of eating disorders (EDs), including anorexia nervosa (AN), bulimia and binge-eating disorder (BED), are currently unknown. Previous data indicated that immunoglobulins (Igs) or autoantibodies (auto-Abs) reactive with α-melanocyte-stimulating hormone (α-MSH) are involved in regulation of feeding and emotion; however, the origin of such auto-Abs is unknown. Here, using proteomics, we identified ClpB heat-shock disaggregation chaperone protein of commensal gut bacteria Escherichia coli as a conformational antigen mimetic of α-MSH. We show that ClpB-immunized mice produce anti-ClpB IgG crossreactive with α-MSH, influencing food intake, body weight, anxiety and melanocortin receptor 4 signaling. Furthermore, chronic intragastric delivery of E. coli in mice decreased food intake and stimulated formation of ClpB- and α-MSH-reactive antibodies, while ClpB-deficient E. coli did not affect food intake or antibody levels. Finally, we show that plasma levels of anti-ClpB IgG crossreactive with α-MSH are increased in patients with AN, bulimia and BED, and that the ED Inventory-2 scores in ED patients correlate with anti-ClpB IgG and IgM, which is similar to our previous findings for α-MSH auto-Abs. In conclusion, this work shows that the bacterial ClpB protein, which is present in several commensal and pathogenic microorganisms, can be responsible for the production of auto-Abs crossreactive with α-MSH, associated with altered feeding and emotion in humans with ED. Our data suggest that ClpB-expressing gut microorganisms might be involved in the etiology of EDs.

Antibiotic resistance in adult female patients hospitalized for acute pyelonephritis: rates and predicting factors.

INTRODUCTION: The empiric treatment of acute pyelonephritis (APN) with third generation cephalosporins (3GC) or fluoroquinolones (FQ) has been challenged by Escherichia coli resistance reported by community surveillance networks. But these could overestimate resistance because they do not discriminate between uncomplicated and complicated, or between community and care-related infections. OBJECTIVES: We had for aim to: quantify resistance rates in hospitalized patients presenting with APN; identify subgroups with resistance <10% that could still be treated empirically with FQ or 3GC. PATIENTS AND METHODS: We retrospectively analyzed files of patients presenting with documented APN, hospitalized in an Infectious Diseases Department from October 2010 to December 2012. RESULTS: Hundred and fifty-six female patients (median age: 66, interquartile range: 37), were admitted for uncomplicated APN (36%) or APN (64%) at risk of complications by 1 (46%), 2 (40%), or 3 or more (14%) risk factors. Bacteremia was associated in 44% of uncomplicated and 8% of APN at risk of complications. E. coli was predominant (82%), resistant to 3GC in 6% of patients (including 4% ESBL) and to FQ in 15% of patients. The rate of resistance to FQ increased with the number of risk factors for complication, from 6% in uncomplicated APN, to 25% in patients with ≥3 risk factors. No enterobacteria was resistant to either 3GC or aminoglycosides. CONCLUSION: The resistance rates of 3GC and aminoglycosides were <10% in patients hospitalized for APN. FQ resistance rates reached 15% but only 6% in uncomplicated APN. Hence, FQ empiric regimen should now be restricted to the treatment of uncomplicated APN without severe sepsis.

Unique blood culture for diagnosis of bloodstream infections in emergency departments: a prospective multicentre study.

Detection of microorganisms by blood cultures (BCs) is essential in managing patients with bacteraemia. Rather than the number of punctures, the volume of blood drawn is considered paramount in efficient and reliable detection of microorganisms. We performed a 1-year prospective multicentre study in adult emergency departments of three French university hospitals comparing two methods for BCs: a unique blood culture (UBC) collecting a large volume of blood (40 mL) and the standard method of multiple blood cultures (MBC). The performances of both methods for bacterial contamination and efficient microbial detection were compared, each patient serving as his own control. Amongst the 2314 patients included, three hundred were positive for pathogens (n=245) or contaminants (n=55). Out of the 245 patients, 11 were positive for pathogens by UBC but negative by MBC and seven negative by UBC but positive by MBC (p 0.480). In the subgroup of 137 patients with only two BCs, UBC was superior to MBC (p 0.044). Seven and 17 patients had contaminated BCs by UBC and MBC only, respectively (p 0.062). Considering the sums of pathogens missed and contaminants, UBC significantly outperformed MBC (p 0.045). Considering the complete picture of cost savings, efficient detection of microorganisms and decrease in contaminations, UBC offers an interesting alternative to MBC.

[Acute respiratory failure due to Mycoplasma pneumonia]. / Détresse respiratoire aiguë due à Mycoplasma pneumoniae.

INTRODUCTION: Respiratory infections due to Mycoplasma pneumoniae are typically mild and subacute. We report the case of a 40-year-old man hospitalized for acute respiratory distress in the context of an acute infection with Mycoplasma pneumoniae. Radiological and pulmonary function test were consistent with an acute infectious bronchiolitis. CASE REPORT: The patient presented with isolated respiratory failure with profound hypoxemia requiring oxygen delivered at high concentration by face mask. The CT appearance of the lesions corresponded to a spread of bilateral micro-connected pulmonary nodules (a "tree-in-bud" pattern) associated with obstructive ventilatory disorder. The only pathogen identified by PCR on BAL and serology was Mycoplasma pneumoniae. The evolution was favorable with antibiotic therapy combined with corticosteroids. CONCLUSION: Mycoplasma pneumoniae may be responsible for severe respiratory illness in the form of bronchiolitis. In the setting of severe acute community pneumoniae antibiotic treatment which is also effective against Mycoplasma pneumonia should be considered. In this case, corticosteroids may be an effective adjunct by their action on the small airways.

Aerial dispersal of meticillin-resistant Staphylococcus aureus in hospital rooms by infected or colonised patients.

The aim of this study was to assess to what extent patients with meticillin-resistant Staphylococcus aureus (MRSA) at respiratory sites shed viable MRSA into the air of hospital rooms. We also evaluated whether the distance from the patient could influence the level of contamination. Air sampling was performed directly onto MRSA-selective agar in 24 hospital rooms containing patients with MRSA colonization or infection of the respiratory tract. Samplings were performed in duplicate at 0.5, 1 and 2-3 m from the patients' heads. Clinical and environmental isolates were compared using antimicrobial resistance patterns and pulsed-field gel electrophoresis. MRSA strains were isolated from 21 out of 24 rooms, in quantities varying from between 1 and 78 cfu/m3. In each of the 21 rooms, at least one of the environmental isolates was identical to a clinical isolate from the patient in that room. There was no significant difference in MRSA counts between the distance from the patient's head and the sampler. This study demonstrates that most patients with MRSA infection or colonisation of the respiratory tract shed viable MRSA into the air of their room. The results emphasise the need to study MRSA in air in more detail in order to improve infection control recommendations.

In vitro synergistic effects of double and triple combinations of beta-lactams, vancomycin, and netilmicin against methicillin-resistant Staphylococcus aureus strains.

Several studies have previously reported synergistic effects between vancomycin and a given beta-lactam or a given aminoglycoside against methicillin-resistant Staphylococcus aureus (MRSA) strains. The aim of our study was to exhaustively compare the effects of different combinations of a beta-lactam, vancomycin, and/or an aminoglycoside against 32 clinical MRSA strains with different aminoglycoside susceptibility patterns. The effects of 26 different beta-lactam-vancomycin and 8 different aminoglycoside-vancomycin combinations were first studied using a disk diffusion screening method. The best interactions with vancomycin were observed with either imipenem, cefazolin, or netilmicin. By checkerboard studies, imipenem-vancomycin and cefazolin-vancomycin each provided a synergistic bacteriostatic effect against 22 strains; the mean fractional inhibitory concentration (FIC) indexes were 0.35 and 0.46 for imipenem-vancomycin and cefazolin-vancomycin, respectively. The vancomycin-netilmicin combination provided an indifferent effect against all of the 32 strains tested; the mean of FIC index was 1. 096. The mean concentrations of imipenem, cefazolin, netilmicin, and vancomycin at which FIC indexes were calculated were clinically achievable. Killing experiments were then performed using imipenem, cefazolin, netilmicin, and vancomycin at one-half of the MIC, alone and in different combinations, against 10 strains. The vancomycin-netilmicin regimen was rarely bactericidal, even against strains susceptible to netilmicin. The imipenem-vancomycin and cefazolin-vancomycin combinations were strongly bactericidal against six and five strains, respectively. The addition of netilmicin markedly enhanced the killing activity of the combination of cefazolin or imipenem plus vancomycin, but only for the MRSA strains against which the beta-lactam-vancomycin combinations had no bactericidal effect. It is noteworthy that the latter strains were both susceptible to netilmicin and heterogeneously resistant to methicillin.

Multilocus enzyme analysis in aerobic and anaerobic bacteria using gel electrophoresis-nitrocellulose blotting.

An optimized multilocus enzyme electrophoresis method, which involves polyacrylamide-agarose gel electrophoresis followed by electrophoretic transfers on nitrocellulose sheets, was developed for the analysis of enzyme polymorphism in several aerobic and anaerobic bacterial species including Staphylococcus aureus, Streptococcus pneumoniae, S. agalactiae, Klebsiella pneumoniae and K. oxytoca, Clostridium bifermentans and C. sordellii, and Prevotella bivia. Serial electrophoretic transfers (during 5-15 min each) from a single polyacrylamide gel could be achieved for most enzymes studied, and allowed an increased definition of enzyme bands on nitrocellulose as compared to migration gels. Four enzymes, which could not be blotted in such conditions, could still be stained in gels after blotting. Thus, the method allowed the combined analysis of several enzymes after a single gel electrophoresis separation. The analysis of enzyme polymorphism in the various species studied raised the interest of polymorphic loci such as esterase or glutamic-oxaloacetic transaminase for epidemiologic studies. The method characterized a genetic diversity of enzyme loci of S. pneumoniae higher than previously reported, and is thus convenient for the analysis of genetic relationships between related isolates. Since the present method reduces the tediousness of multilocus enzyme electrophoresis and requires experimental conditions that are not specific for the bacterial population studied, it may be proposed for rapid population genetics analysis of a wide variety of bacteria.

Usefulness of pulsed-field gel electrophoresis in assessing nosocomial transmission of pertussis.

During a 2-week period, three infants with a cough lasting at least 8 days with whoops, were admitted to the pediatric unit; Bordetella pertussis was isolated from nasopharyngeal aspirates collected from the three infants. Approximately 1 week later, a nurse working on the same unit developed influenza-like symptoms followed by whooping cough; B pertussis was isolated. Isolates from the nurse and from one of the infants were shown to be indistinguishable by pulsed-field gel electrophoresis. These data demonstrate that B pertussis transmission to healthcare workers is possible and emphasize the need to use respiratory protection devices (Droplet Precautions) for healthcare workers having close contact with infected children.

Nosocomial pertussis in healthcare workers from a pediatric emergency unit in France.

OBJECTIVE: After pertussis was diagnosed in July 1997 in a 55-year-old nurse (case) from a pediatric emergency unit who had a respiratory illness and paroxysmal cough for 5 weeks, an epidemiological investigation was initiated to determine if other healthcare workers (HCWs) from the same unit also had pertussis. DESIGN: Interviews were conducted to assess symptoms occurring in the previous months. Two sera were collected 2 to 3 months apart for 59 of 61 HCWs of the unit. The IgG response to pertussis toxin was determined using Western blot assay. SETTING: Pediatric emergency unit (61 HCWs) of a 2,500-bed university hospital. RESULTS: There was a total of 10 (5 confirmed and 5 probable) cases of pertussis identified in this outbreak. Nine HCWs (15%) had results suggesting recent or acute pertussis. To avoid transmission to patients and other HCWs, all HCWs with cough were treated for 14 days with erythromycin, and those having acute cough were given a 5-day sick leave. Despite these measures, a new acute pertussis case was identified in a 41-year-old nurse, with a positive culture from nasopharyngeal aspirates. Thus, all HCWs in the unit were prescribed spiramycin for 10 days to prevent any further spread of pertussis. CONCLUSION: Pertussis should be considered a threat to HCWs who are in contact with children. For HCWs, diagnosis of pertussis should be made on a clinical basis, giving greater importance to sensitivity of diagnosis criteria, and on early bacterial identification by culture of the organism or by polymerase chain reaction. RECOMMENDATIONS: In case of pertussis in an HCW, all staff in the unit who have had unprotected and intensive contact with that person should be provided with macrolide treatment to stop any transmission to colleagues and to young patients. Furthermore, the possibility of providing these HCWs with acellular pertussis vaccines warrants further investigation.

Molecular analysis of Mycobacterium avium isolates by using pulsed-field gel electrophoresis and PCR.

Genetic relationships among 46 isolates of Mycobacterium avium recovered from 37 patients in a 2,500-bed hospital from 1993 to 1998 were assessed by pulsed-field gel electrophoresis (PFGE) and PCR amplification of genomic sequences located between the repetitive elements IS1245 and IS1311. Each technique enabled the identification of 27 to 32 different patterns among the 46 isolates, confirming that the genetic heterogeneity of M. avium strains is high in a given community. Furthermore, this retrospective analysis of sporadic isolates allowed us (i) to suggest the existence of two remanent strains in our region, (ii) to raise the question of the possibility of nosocomial acquisition of M. avium strains, and (iii) to document laboratory contamination. The methods applied in the present study were found to be useful for the typing of M. avium isolates. In general, both methods yielded similar results for both related and unrelated isolates. However, the isolates in five of the six PCR clusters were distributed among two to three PFGE patterns, suggesting that this PCR-based method may have limitations for the analysis of strains with low insertion sequence copy numbers or for resolution of extended epidemiologic relationships.

Characterization of IS1245 for strain typing of Mycobacterium avium.

IS1245 is an insertion element widely prevalent among isolates of Mycobacterium avium. We used PvuII Southern blots to analyze IS1245 polymorphisms among 159 M. avium isolates (141 clinical isolates from 40 human immunodeficiency virus-infected patients plus 18 epidemiologically related environmental isolates) that represented 40 distinct M. avium strains, as resolved by previous studies by pulsed-field gel electrophoresis (PFGE). All 40 strains carried DNA homologous to IS1245 and thus were typeable. Twenty-five (63%) strains had > or = 10 copies of the element, 6 (15%) had 4 to 9 copies, and 9 (23%) had only 1 to 3 copies. Among the last group of nine strains (each of which was distinct by PFGE analysis), IS1245 typing resolved only four patterns and thus provided poor discriminatory power. To evaluate the in vivo stability of IS1245, we analyzed 32 strains for which sets of 2 to 19 epidemiologically related isolates were available. For 19 (59%) of these sets, all isolates representing the same strain had indistinguishable IS1245 patterns. Within eight (25%) sets, one or more isolates had IS1245 patterns that differed by one or two fragments from the modal pattern for the isolates of that strain. Five (16%) sets included isolates whose patterns differed by three or more fragments; on the basis of IS1245 typing those isolates would have been designated distinct strains. IS1245 was stable during in vitro passage, suggesting that the variations observed represented natural translocations of the element. IS1245 provides a useful tool for molecular strain typing of M. avium but may have limitations for analyzing strains with low copy numbers or for resolving extended epidemiologic relationships.