Mycobacterium abscessus is an emerging rapidly growing mycobacterium that causes tuberculous-like... more Mycobacterium abscessus is an emerging rapidly growing mycobacterium that causes tuberculous-like lesions in humans. We studied the immune control of this organism in C57BL/6 mice challenged intravenously with 10 7 CFU. Bacteria were eliminated from both the spleen and the liver within 90 days, and liver histology showed organized granulomatous lesions. A T- and B-cell requirement was investigated by challenging Rag2 − / − , Cd3 ε − / − , and μ MT − / − mice. Rag2 − / − and Cd3 ε − / − mice were significantly impaired in the ability to clear M. abscessus from the liver and spleen, and μ MT − / − mice were significantly impaired in the ability to clear M. abscessus from the liver, suggesting that infection control was primarily T cell dependent in the spleen and both T and B cell dependent in the liver. The liver granulomatous response was similar to that of wild-type controls in μ MT − / − mice but completely absent in Cd3 ε − / − and Rag2 − / − mice. We studied the involvement of g...
Aim Pre-operative distinction between prosthetic joint infections (PJI) and non-infectious causes... more Aim Pre-operative distinction between prosthetic joint infections (PJI) and non-infectious causes of joint failure is particularly challenging, especially in chronic situations. Guidelines propose different algorithms using numerous preoperative tests. We evaluated place of serology. Method During a 9 month period, we included consecutive patients undergoing arthroplasty revision for a suspected chronic hip or knee infection. Serologies were sampled at the same day than the other blood tests. Results were compared with the final diagnosis, determined with peroperative bacteriological and histological results. Serology was performed using a multiplex antibody detection*. This multiplex antibody detection assay detects antibodies against Staphylococcus species, Propionibacterium acnes and Streptococcus agalactiae. Results A total of 52 patients were enrolled. Median time from last arthroplasty was 30 months (extremes 8 months − 17 years). Median clinical signs duration was 6 months (e...
OBJECTIVES Blood culture bottles (BCBs) are commonly used for the diagnosis of infections associa... more OBJECTIVES Blood culture bottles (BCBs) are commonly used for the diagnosis of infections associated with orthopedic devices. Although Cutibacterium acnes is an important pathogen in orthopedics, relatively little is known about its growth characteristics in BCBs. This prompted us to analyze the influence of bacterial genotype and clinical significance on time-to-detection (TTD) in BCBs. METHODS We reviewed 59 cases of orthopedic device-related infections in which at least one intraoperative specimen yielded a pure C. acnes culture from anaerobic BCBs (BD Bactec Lytic/10 Anaerobic/F; Lytic-Ana) and/or solid media. A strain was considered infectant if the same genotype was present in two or more intraoperative samples. From these cases, we isolated a total of 72 unique C. acnes strains belonging to four multilocus sequence type clonal complexes (CCs): CC18, CC28, CC36 and CC53. Growth rate and TTD in Lytic-Ana BCB were studied under experimental conditions (inoculation of standard inoculum) and in clinical samples (inoculation of periprosthetic tissue samples). RESULTS Median TTD values were shorter for CC53 compared to other CCs under experimental conditions (69 vs. 103 h; p < 0.001) and from clinical specimens (70 vs. 200 h; p = 0.02). Infectant strains had a shorter median TTD compared to contaminant strains in a clinical situation, while the difference was not observed under experimental conditions. CONCLUSIONS The detection dynamics of C. acnes in Lytic-Ana BCBs were associated with genotype. Thus, TTD not only reflects the bacterial load in clinical samples, but may also reflect the intrinsic properties of the clonal complex of C. acnes.
Dear Editor, Corticosteroids are recommended for complicated sepsis [1]. However, their positive ... more Dear Editor, Corticosteroids are recommended for complicated sepsis [1]. However, their positive average effects demonstrated in trials translates into individual effects ranging from harm to survival benefit [2]. Biomarkers preventing unsafe corticosteroids exposure are needed. Owing to the role of monocyte in corticosteroids effects [3], we hypothesized that monocyte distribution width (MDW) may identify corticosteroids-resistance in sepsis. We prospectively categorized consecutive hospitalized adults according to the presence of infection, sepsis or septic shock, and corticotherapy [4] (Supplementary material). Ethics Committee and Commission Nationale de l’Informatique et des Libertés approved waiver of consent. The study protocol and statistical analysis plan are available at https:// www. fhusepsis. uvsq. fr/ sepsis, and registered at ClinicalTrials.gov under NCT04292431. Corticosteroids-resistance was defined by day-7 death, vasopressors or mechanical ventilation-dependency, or sequential organ failure assessment (SOFA) score > 6. Data were abstracted weekly from the electronic health record, deidentified, and stored for subsequent analysis. Researchers remained blinded to participants’ identity. At routine blood sampling, MDW, the index test, was analysed (Unicell DxH 900 analyzer, Beckman Coulter, USA) and results were kept undisclosed. This exploratory study had no formal sample size calculation. Evaluation of biomarkers performance to identify the corticosteroids-resistance used analysis of receiver operating characteristic (ROC) and decision curves, i.e. estimates of standardized net benefit by probability threshold categorizing observations as corticosteroids-resistance, and logistic regression models with odds ratio (OR). Of 1676 patients, 1496 had measurements of MDW (Supplementary material, Fig. 1). There were 197 patients with infection, 89 with sepsis, and 40 with septic shock (Supplementary material, Table 1). Age was not significantly different between groups (P = 0.16). Patients with sepsis or septic shock were more likely male (P = 0.018), mechanically ventilated (P < 0.0001), ICU-dependent (P < 0.0001). Of 191 corticosteroids-treated patients, 67 had corticosteroidsresistance (Supplementary material, Table 2). MDW increased gradually from no infection to septic shock (Fig. 1A). Median MDW was 24.5 (IQR, 22.2–27.9) and 21.7 (19.9–25.5) in patients with versus without corticosteroids-resistance (P = 0.0004) (Fig. 1B, Supplementary material, Table 3 and Fig. 2). Figure 1C displayed ROC curves analysis for corticosteroids-resistance. Sensitivity analyses by individual criteria and excluding one criteria of the definition of corticosteroids-resistance, yielded consistent AUC (Supplementary material, Figs. 3, 4). When MDW > 25, the OR for corticosteroids-resistance was 2.33 (95% CI 1.33–4.44, P = 0.0098) and outperforming other laboratory tests (Supplementary material, Tables 3, 4). By multivariate analysis, corticosteroids-resistance was associated with higher MDW (P = 0.0082), and lower neutrophil mean volume (P = 0.0094) and lymphocytes count (P = 0.0017) (Table 1). After adjusting for baseline requirement of vasopressor, mechanical ventilation and SOFA score, corticosteroids-resistance remained associated with higher MDW (P = 0.035, Table 1). There was no interaction between MDW effect on corticosteroids-resistance, *Correspondence: Djillali.annane@aphp.fr Department of Intensive Care, Hôpital Raymond Poincaré (APHP), 104 Boulevard Raymond Poincaré, 92380 Garches, France
Potential of hydrogen (pH) is one of the most relevant parameters characterizing aqueous solution... more Potential of hydrogen (pH) is one of the most relevant parameters characterizing aqueous solutions. In biology, pH is intrinsically linked to cellular life since all metabolic pathways are implicated into ionic flows. In that way, determination of local pH offers a unique and major opportunity to increase our understanding of biological systems. Whereas the most common technique to obtain these data in analytical chemistry is to directly measure potential between two electrodes, in biological systems, this information has to be recovered in-situ without any physical interaction. Based on their non-invasive optical properties, fluorescent pH-sensitive probe are pertinent tools to develop. One of the most notorious pH-sensitive probes is fluorescein. In addition to excellent photophysical properties, this fluorophore presents a pH-sensitivity around neutral and physiologic domains. This review intends to shed new light on the recent use of fluorescein as pH-sensitive probes for biolog...
Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lu... more Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lung cancer (NSCLC). An unmet need remains for new biomarkers associated with ICIs. In this study, consecutive patients with advanced NSCLC treated with nivolumab or pembrolizumab were included. Plasma at ICIs initiation was prospectively collected and a multiplex ELISA assay testing 48 cytokines and growth factors was performed. Exploratory endpoints were the association between plasma biomarkers with outcome and grade III–IV immune related adverse events (irAEs). Thirty-five patients were included. Patients without clinical benefit (n = 22) had higher pre-ICI soluble Hepatocyte Growth Factor (sHGF) (210.9 vs. 155.8 pg/mL, p = 0.010), lower pre-ICI soluble Fibroblast Growth Factor (sFGF) (4.0 vs. 4.8 pg/mL, p = 0.043) and lower pre-ICI interleukine-12 (IL-12) (1.3 vs. 2.2 pg/mL, p = 0.043) concentrations. Patients with early progression (n = 23) had higher pre-ICIs sHGF (206.2 vs. 155.8 p...
Cutibacterium acnes is a major etiologic agent of orthopaedic implant-associated infections (IAIs... more Cutibacterium acnes is a major etiologic agent of orthopaedic implant-associated infections (IAIs) and requires up to 14 days of incubation in an anaerobic atmosphere for growth detection. As blood culture (BC) systems are increasingly being used to monitor the growth of IAI specimens, we compared different BC media for growth detection of C. acnes. Non-duplicate C. acnes isolates (n = 99) obtained from sonicate-fluid cultures of orthopaedic IAIs from Slovenia (n = 54), conventional tissue samples of monomicrobial orthopaedic IAIs from France (n = 43) and two reference strains were inoculated to anaerobic BC bottles of two major BC systems and 3 conventional culture media types (thioglycolate broth, Schaedler and chocolate agar). Growth and time-to-detection (TTD) were recorded. Only Lytic (BACTEC) and SN (BacT/ALERT) bottles consistently detected growth of C. acnes within 14 days with 94% (n = 93) and 92% (n = 91) detection rates, respectively (p = 0.79). Lytic was superior to Plus BACTEC medium (p < 0.001), while SN was superior to all other BacT/ALERT media (p < 0.001). Mean TTD was 128 ± 43 h (61-336 h) for Lytic and 158 ± 65 h (77-336 h) for SN medium. Among the conventional media, 99% (n = 98) of the isolates grew on Schaedler agar, 96% (n = 95) in thioglycolate broth and 74% (n = 73) on chocolate agar. Inconsistent growth of C. acnes in different BC media can critically influence the detection of this major IAI pathogen. Only Lytic (BACTEC) and SN (BacT/ALERT) BC media types were consistently able to detect C. acnes within 14 days of incubation. However, visible growth was observed faster in thioglycolate broth and Schaedler agar media.
European Journal of Clinical Microbiology & Infectious Diseases
Corynebacterium striatum is a ubiquitous colonizer of human skin and mucous membranes. It is incr... more Corynebacterium striatum is a ubiquitous colonizer of human skin and mucous membranes. It is increasingly involved in infections, especially with prosthetic devices or in immunocompromised individuals. Microbiological diagnosis is challenging and bacterial resistance is a major concern. We performed a retrospective study of monomicrobial bone and joint infections (BJI) due to C. striatum in two referral centers from April 2012 to July 2017. We collected the patients’ clinical and microbiological characteristics and outcomes. We also performed a literature review of BJI due to C. striatum. We identified 12 cases (nine prosthetic joint infections, one osteosynthetic device infection, one non-union, and one arthritis) in 11 patients, five of which were immunocompromised. Microbiological diagnosis was performed with prolonged culture media. Ten out of 12 strains were susceptible to aminopenicillin, a drug class not recommended for testing by the EUCAST/CASFM guidelines, and 8/12 patients were treated with amoxicillin-rifampicin. The cure rate was 8/12, after a median follow-up period of 487.5 days (IQR 140.3–1348.5). Twelve cases of BJI due to C. striatum were previously reported. Among them, 5/12 patients were immunocompromised, 3/12 cases were acute BJI, and 2/12 were device-related infections. The diagnosis was performed by PCR in one case, and 10/12 patients were treated with glycolipopeptides, with a cure rate of 11/12. We report the largest cohort of monomicrobial BJI with C. striatum. Determination of aminopenicillin susceptibility is essential since it is frequently active in our experience, even in BJI. The cure rate of this infection seems high.
Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium responsible for pulmonary ... more Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium responsible for pulmonary and cutaneous infections in immunocompetent patients and in patients with Mendelian disorders, such as cystic fibrosis (CF). Mycobacterium abscessus is known to transition from a smooth (S) morphotype with cell surface-associated glycopeptidolipids (GPL) to a rough (R) morphotype lacking GPL. Herein, we show that M. abscessus S and R variants are able to grow inside macrophages and are present in morphologically distinct phagosomes. The S forms are found mostly as single bacteria within phagosomes characterized by a tightly apposed phagosomal membrane and the presence of an electron translucent zone (ETZ) surrounding the bacilli. By contrast, infection with the R form leads to phagosomes often containing more than two bacilli, surrounded by a loose phagosomal membrane and lacking the ETZ. In contrast to the R variant, the S variant is capable of restricting intraphagosomal acidification ...
Mycobacterium abscessus is an emerging rapidly growing mycobacterium that causes tuberculous-like... more Mycobacterium abscessus is an emerging rapidly growing mycobacterium that causes tuberculous-like lesions in humans. We studied the immune control of this organism in C57BL/6 mice challenged intravenously with 10 7 CFU. Bacteria were eliminated from both the spleen and the liver within 90 days, and liver histology showed organized granulomatous lesions. A T- and B-cell requirement was investigated by challenging Rag2 − / − , Cd3 ε − / − , and μ MT − / − mice. Rag2 − / − and Cd3 ε − / − mice were significantly impaired in the ability to clear M. abscessus from the liver and spleen, and μ MT − / − mice were significantly impaired in the ability to clear M. abscessus from the liver, suggesting that infection control was primarily T cell dependent in the spleen and both T and B cell dependent in the liver. The liver granulomatous response was similar to that of wild-type controls in μ MT − / − mice but completely absent in Cd3 ε − / − and Rag2 − / − mice. We studied the involvement of g...
Aim Pre-operative distinction between prosthetic joint infections (PJI) and non-infectious causes... more Aim Pre-operative distinction between prosthetic joint infections (PJI) and non-infectious causes of joint failure is particularly challenging, especially in chronic situations. Guidelines propose different algorithms using numerous preoperative tests. We evaluated place of serology. Method During a 9 month period, we included consecutive patients undergoing arthroplasty revision for a suspected chronic hip or knee infection. Serologies were sampled at the same day than the other blood tests. Results were compared with the final diagnosis, determined with peroperative bacteriological and histological results. Serology was performed using a multiplex antibody detection*. This multiplex antibody detection assay detects antibodies against Staphylococcus species, Propionibacterium acnes and Streptococcus agalactiae. Results A total of 52 patients were enrolled. Median time from last arthroplasty was 30 months (extremes 8 months − 17 years). Median clinical signs duration was 6 months (e...
OBJECTIVES Blood culture bottles (BCBs) are commonly used for the diagnosis of infections associa... more OBJECTIVES Blood culture bottles (BCBs) are commonly used for the diagnosis of infections associated with orthopedic devices. Although Cutibacterium acnes is an important pathogen in orthopedics, relatively little is known about its growth characteristics in BCBs. This prompted us to analyze the influence of bacterial genotype and clinical significance on time-to-detection (TTD) in BCBs. METHODS We reviewed 59 cases of orthopedic device-related infections in which at least one intraoperative specimen yielded a pure C. acnes culture from anaerobic BCBs (BD Bactec Lytic/10 Anaerobic/F; Lytic-Ana) and/or solid media. A strain was considered infectant if the same genotype was present in two or more intraoperative samples. From these cases, we isolated a total of 72 unique C. acnes strains belonging to four multilocus sequence type clonal complexes (CCs): CC18, CC28, CC36 and CC53. Growth rate and TTD in Lytic-Ana BCB were studied under experimental conditions (inoculation of standard inoculum) and in clinical samples (inoculation of periprosthetic tissue samples). RESULTS Median TTD values were shorter for CC53 compared to other CCs under experimental conditions (69 vs. 103 h; p < 0.001) and from clinical specimens (70 vs. 200 h; p = 0.02). Infectant strains had a shorter median TTD compared to contaminant strains in a clinical situation, while the difference was not observed under experimental conditions. CONCLUSIONS The detection dynamics of C. acnes in Lytic-Ana BCBs were associated with genotype. Thus, TTD not only reflects the bacterial load in clinical samples, but may also reflect the intrinsic properties of the clonal complex of C. acnes.
Dear Editor, Corticosteroids are recommended for complicated sepsis [1]. However, their positive ... more Dear Editor, Corticosteroids are recommended for complicated sepsis [1]. However, their positive average effects demonstrated in trials translates into individual effects ranging from harm to survival benefit [2]. Biomarkers preventing unsafe corticosteroids exposure are needed. Owing to the role of monocyte in corticosteroids effects [3], we hypothesized that monocyte distribution width (MDW) may identify corticosteroids-resistance in sepsis. We prospectively categorized consecutive hospitalized adults according to the presence of infection, sepsis or septic shock, and corticotherapy [4] (Supplementary material). Ethics Committee and Commission Nationale de l’Informatique et des Libertés approved waiver of consent. The study protocol and statistical analysis plan are available at https:// www. fhusepsis. uvsq. fr/ sepsis, and registered at ClinicalTrials.gov under NCT04292431. Corticosteroids-resistance was defined by day-7 death, vasopressors or mechanical ventilation-dependency, or sequential organ failure assessment (SOFA) score > 6. Data were abstracted weekly from the electronic health record, deidentified, and stored for subsequent analysis. Researchers remained blinded to participants’ identity. At routine blood sampling, MDW, the index test, was analysed (Unicell DxH 900 analyzer, Beckman Coulter, USA) and results were kept undisclosed. This exploratory study had no formal sample size calculation. Evaluation of biomarkers performance to identify the corticosteroids-resistance used analysis of receiver operating characteristic (ROC) and decision curves, i.e. estimates of standardized net benefit by probability threshold categorizing observations as corticosteroids-resistance, and logistic regression models with odds ratio (OR). Of 1676 patients, 1496 had measurements of MDW (Supplementary material, Fig. 1). There were 197 patients with infection, 89 with sepsis, and 40 with septic shock (Supplementary material, Table 1). Age was not significantly different between groups (P = 0.16). Patients with sepsis or septic shock were more likely male (P = 0.018), mechanically ventilated (P < 0.0001), ICU-dependent (P < 0.0001). Of 191 corticosteroids-treated patients, 67 had corticosteroidsresistance (Supplementary material, Table 2). MDW increased gradually from no infection to septic shock (Fig. 1A). Median MDW was 24.5 (IQR, 22.2–27.9) and 21.7 (19.9–25.5) in patients with versus without corticosteroids-resistance (P = 0.0004) (Fig. 1B, Supplementary material, Table 3 and Fig. 2). Figure 1C displayed ROC curves analysis for corticosteroids-resistance. Sensitivity analyses by individual criteria and excluding one criteria of the definition of corticosteroids-resistance, yielded consistent AUC (Supplementary material, Figs. 3, 4). When MDW > 25, the OR for corticosteroids-resistance was 2.33 (95% CI 1.33–4.44, P = 0.0098) and outperforming other laboratory tests (Supplementary material, Tables 3, 4). By multivariate analysis, corticosteroids-resistance was associated with higher MDW (P = 0.0082), and lower neutrophil mean volume (P = 0.0094) and lymphocytes count (P = 0.0017) (Table 1). After adjusting for baseline requirement of vasopressor, mechanical ventilation and SOFA score, corticosteroids-resistance remained associated with higher MDW (P = 0.035, Table 1). There was no interaction between MDW effect on corticosteroids-resistance, *Correspondence: Djillali.annane@aphp.fr Department of Intensive Care, Hôpital Raymond Poincaré (APHP), 104 Boulevard Raymond Poincaré, 92380 Garches, France
Potential of hydrogen (pH) is one of the most relevant parameters characterizing aqueous solution... more Potential of hydrogen (pH) is one of the most relevant parameters characterizing aqueous solutions. In biology, pH is intrinsically linked to cellular life since all metabolic pathways are implicated into ionic flows. In that way, determination of local pH offers a unique and major opportunity to increase our understanding of biological systems. Whereas the most common technique to obtain these data in analytical chemistry is to directly measure potential between two electrodes, in biological systems, this information has to be recovered in-situ without any physical interaction. Based on their non-invasive optical properties, fluorescent pH-sensitive probe are pertinent tools to develop. One of the most notorious pH-sensitive probes is fluorescein. In addition to excellent photophysical properties, this fluorophore presents a pH-sensitivity around neutral and physiologic domains. This review intends to shed new light on the recent use of fluorescein as pH-sensitive probes for biolog...
Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lu... more Immune checkpoint inhibitors (ICIs) are commonly used in patients with advanced non-small cell lung cancer (NSCLC). An unmet need remains for new biomarkers associated with ICIs. In this study, consecutive patients with advanced NSCLC treated with nivolumab or pembrolizumab were included. Plasma at ICIs initiation was prospectively collected and a multiplex ELISA assay testing 48 cytokines and growth factors was performed. Exploratory endpoints were the association between plasma biomarkers with outcome and grade III–IV immune related adverse events (irAEs). Thirty-five patients were included. Patients without clinical benefit (n = 22) had higher pre-ICI soluble Hepatocyte Growth Factor (sHGF) (210.9 vs. 155.8 pg/mL, p = 0.010), lower pre-ICI soluble Fibroblast Growth Factor (sFGF) (4.0 vs. 4.8 pg/mL, p = 0.043) and lower pre-ICI interleukine-12 (IL-12) (1.3 vs. 2.2 pg/mL, p = 0.043) concentrations. Patients with early progression (n = 23) had higher pre-ICIs sHGF (206.2 vs. 155.8 p...
Cutibacterium acnes is a major etiologic agent of orthopaedic implant-associated infections (IAIs... more Cutibacterium acnes is a major etiologic agent of orthopaedic implant-associated infections (IAIs) and requires up to 14 days of incubation in an anaerobic atmosphere for growth detection. As blood culture (BC) systems are increasingly being used to monitor the growth of IAI specimens, we compared different BC media for growth detection of C. acnes. Non-duplicate C. acnes isolates (n = 99) obtained from sonicate-fluid cultures of orthopaedic IAIs from Slovenia (n = 54), conventional tissue samples of monomicrobial orthopaedic IAIs from France (n = 43) and two reference strains were inoculated to anaerobic BC bottles of two major BC systems and 3 conventional culture media types (thioglycolate broth, Schaedler and chocolate agar). Growth and time-to-detection (TTD) were recorded. Only Lytic (BACTEC) and SN (BacT/ALERT) bottles consistently detected growth of C. acnes within 14 days with 94% (n = 93) and 92% (n = 91) detection rates, respectively (p = 0.79). Lytic was superior to Plus BACTEC medium (p < 0.001), while SN was superior to all other BacT/ALERT media (p < 0.001). Mean TTD was 128 ± 43 h (61-336 h) for Lytic and 158 ± 65 h (77-336 h) for SN medium. Among the conventional media, 99% (n = 98) of the isolates grew on Schaedler agar, 96% (n = 95) in thioglycolate broth and 74% (n = 73) on chocolate agar. Inconsistent growth of C. acnes in different BC media can critically influence the detection of this major IAI pathogen. Only Lytic (BACTEC) and SN (BacT/ALERT) BC media types were consistently able to detect C. acnes within 14 days of incubation. However, visible growth was observed faster in thioglycolate broth and Schaedler agar media.
European Journal of Clinical Microbiology & Infectious Diseases
Corynebacterium striatum is a ubiquitous colonizer of human skin and mucous membranes. It is incr... more Corynebacterium striatum is a ubiquitous colonizer of human skin and mucous membranes. It is increasingly involved in infections, especially with prosthetic devices or in immunocompromised individuals. Microbiological diagnosis is challenging and bacterial resistance is a major concern. We performed a retrospective study of monomicrobial bone and joint infections (BJI) due to C. striatum in two referral centers from April 2012 to July 2017. We collected the patients’ clinical and microbiological characteristics and outcomes. We also performed a literature review of BJI due to C. striatum. We identified 12 cases (nine prosthetic joint infections, one osteosynthetic device infection, one non-union, and one arthritis) in 11 patients, five of which were immunocompromised. Microbiological diagnosis was performed with prolonged culture media. Ten out of 12 strains were susceptible to aminopenicillin, a drug class not recommended for testing by the EUCAST/CASFM guidelines, and 8/12 patients were treated with amoxicillin-rifampicin. The cure rate was 8/12, after a median follow-up period of 487.5 days (IQR 140.3–1348.5). Twelve cases of BJI due to C. striatum were previously reported. Among them, 5/12 patients were immunocompromised, 3/12 cases were acute BJI, and 2/12 were device-related infections. The diagnosis was performed by PCR in one case, and 10/12 patients were treated with glycolipopeptides, with a cure rate of 11/12. We report the largest cohort of monomicrobial BJI with C. striatum. Determination of aminopenicillin susceptibility is essential since it is frequently active in our experience, even in BJI. The cure rate of this infection seems high.
Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium responsible for pulmonary ... more Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium responsible for pulmonary and cutaneous infections in immunocompetent patients and in patients with Mendelian disorders, such as cystic fibrosis (CF). Mycobacterium abscessus is known to transition from a smooth (S) morphotype with cell surface-associated glycopeptidolipids (GPL) to a rough (R) morphotype lacking GPL. Herein, we show that M. abscessus S and R variants are able to grow inside macrophages and are present in morphologically distinct phagosomes. The S forms are found mostly as single bacteria within phagosomes characterized by a tightly apposed phagosomal membrane and the presence of an electron translucent zone (ETZ) surrounding the bacilli. By contrast, infection with the R form leads to phagosomes often containing more than two bacilli, surrounded by a loose phagosomal membrane and lacking the ETZ. In contrast to the R variant, the S variant is capable of restricting intraphagosomal acidification ...
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Papers by Martin Rottman