Enterococcus hirae and Barnesiella intestinihominis Facilitate Cyclophosphamide-Induced Therapeutic Immunomodulatory Effects.

The efficacy of the anti-cancer immunomodulatory agent cyclophosphamide (CTX) relies on intestinal bacteria. How and which relevant bacterial species are involved in tumor immunosurveillance, and their mechanism of action are unclear. Here, we identified two bacterial species, Enterococcus hirae and Barnesiella intestinihominis that are involved during CTX therapy. Whereas E. hirae translocated from the small intestine to secondary lymphoid organs and increased the intratumoral CD8/Treg ratio, B. intestinihominis accumulated in the colon and promoted the infiltration of IFN-γ-producing γδT cells in cancer lesions. The immune sensor, NOD2, limited CTX-induced cancer immunosurveillance and the bioactivity of these microbes. Finally, E. hirae and B. intestinihominis specific-memory Th1 cell immune responses selectively predicted longer progression-free survival in advanced lung and ovarian cancer patients treated with chemo-immunotherapy. Altogether, E. hirae and B. intestinihominis represent valuable "oncomicrobiotics" ameliorating the efficacy of the most common alkylating immunomodulatory compound.

Thyroid nocardiosis: Case report and review of the literature.

Disseminated nocardiosis is a rare but growing concern in immunocompromised patients. Typical localizations include the lung, brain and/or soft tissues, but laboratory confirmation of nocardiosis usually requires sampling of infected organs by invasive procedures such as bronchoalveolar lavage or brain biopsy. We report a case of disseminated nocardiosis occurring in a hematopoietic stem-cell transplant recipient, with clinical lung and brain localizations. Examination of the thyroid gland was suggestive of a unilateral abscess. A culture of thyroid pus sampled by fine-needle aspiration was positive for Nocardia farcinica and therefore avoided a more invasive procedure. The patient recovered after a six-month antibiotic therapy without thyroid surgery. We reviewed other ten cases of thyroid nocardiosis published in the medical literature. Among the ten cases of disseminated nocardiosis established during the patient's lifetime including ours, six (60%) were asymptomatic and seven (70%) were confirmed by culture of the aspiration of thyroid pus. When disseminated nocardiosis is suspected, systematic examination for a thyroid abscess may help establish a microbiological diagnosis and prevent further invasive procedures.

[Gastric bacterial overgrowth: An unusual histological observation, not to be overlooked]. / Pullulation bactérienne gastrique : une observation histologique inhabituelle, à ne pas méconnaître.

Gastric bacterial overgrowth is a rare situation, which may be associated with short- and long-term complications. It must be known from pathologists, since it might be detected incidentally at histological examination of gastric biopsies. We report here the case of a 74-year old woman, obese, without significant medical history, apart from a gastro-esophageal reflux treated by the long-term administration of proton pump inhibitors (PPI). In this patient, gastric bacterial overgrowth was detected at histological examination of gastric biopsies performed after colectomy for left colon adenocarcinoma. Large clusters of small, round, "coccoid" bacteria were present in the gastric mucus. Their characteristics were suggestive of enterobacteria. Bacterial proliferation was associated with severe and diffuse lesions of active gastritis. The course was rapidly unfavorable, and the patient rapidly deceased with multiple infections and multi-organ failure. In our observation, the pathogenesis of gastric bacterial overgrowth was probably multifactorial. It might have been facilitated by long-term PPI treatment and obesity, which are known risk factors, and promoted, in the post-operative setting, by multiple infections and immune failure. Our observation underlines that gastric bacterial overgrowth might be associated with severe gastritis, which might justify antibiotherapy. Other consequences of prolonged gastric dysbiosis cannot be excluded, such as the promotion of neoplastic lesions.

Protection of the Human Gut Microbiome From Antibiotics.

Background: Antibiotics are life-saving drugs but severely affect the gut microbiome with short-term consequences including diarrhea and selection of antibiotic-resistant bacteria. Long-term links to allergy and obesity are also suggested. We devised a product, DAV132, and previously showed its ability to deliver a powerful adsorbent, activated charcoal, in the late ileum of human volunteers. Methods: We performed a randomized controlled trial in 28 human volunteers treated with a 5-day clinical regimen of the fluoroquinolone antibiotic moxifloxacin in 2 parallel groups, with or without DAV132 coadministration. Two control goups of 8 volunteers each receiving DAV132 alone, or a nonactive substitute, were added. Results: The coadministration of DAV132 decreased free moxifloxacin fecal concentrations by 99%, while plasmatic levels were unaffected. Shotgun quantitative metagenomics showed that the richness and composition of the intestinal microbiota were largely preserved in subjects co-treated with DAV132 in addition to moxifloxacin. No adverse effect was observed. In addition, DAV132 efficiently adsorbed a wide range of clinically relevant antibiotics ex vivo. Conclusions: DAV132 was highly effective to protect the gut microbiome of moxifloxacin-treated healthy volunteers and may constitute a clinical breakthrough by preventing adverse health consequences of a wide range of antibiotic treatments. Clinical Trials Registration: NCT02176005.

Mycobacterium mucogenicum bacteremia: major role of clinical microbiologists.

INTRODUCTION: Mycobacterium mucogenicum is a rare but emerging cause of infections, especially in immunocompromised patients. CASE PRESENTATION: We describe a new case of M. mucogenicum catheter-related bloodstream infection in a 34-year-old woman with ovarian cancer. M. mucogenicum was at first considered as a contaminant, and susceptibility testing was not performed. Usual susceptibility of M. mucogenicum motivated prescription of clarithromycin and moxifloxacin. Finally, our isolate was confirmed susceptible to both drugs. Clinical outcome was favorable with no relapse of infection after antibiotics discontinuation despite concomitant chemotherapy. CONCLUSION: Our case illustrates the need for a clinician-microbiologist dialogue in case of suspected M. mucogenicum infection to avoid delaying appropriate management.

Invasive cutaneous infection due to Scopulariopsis brevicaulis unsuccessfully treated with high-dose micafungin in a neutropenic patient.

Scopulariopsis brevicaulis onychomycosis with local cutaneous invasion was diagnosed in an acute leukemia patient and unsuccessfully treated with high-dose micafungin, based on antifungal susceptibility testing. This case should alert clinicians to the possible severe evolution of onychomycosis in neutropenic patients and suggests that surgery should be preferred in such a situation.

Eggerthella lenta bacteremia in solid tumor cancer patients: Pathogen or witness of frailty?

Eggerthella lenta is increasingly found in patients with severe comorbidities. Because oncologic patients are exposed to emerging pathogens, we aimed to describe the factors associated with E. lenta bacteremia in this immunosuppressed population. Oncology patients with blood cultures positive for E. lenta were retrospectively recorded from 2009 to 2015. Socio-demographic and medical/biological data as well as potential risk factors and mortality were recorded and analyzed. Twenty-three patients were included. Gastro intestinal (GI) and gynecological cancers were reported in 12/23 (52%) and 7/23 cases (30%), respectively. Eleven/23 patients (48%) had metastatics lesions and 6/23 (26%) had peritoneal carcinomatosis. No associated tissue infection was found in 14/23 cases (61%). Blood cultures yielded at least one other species in addition to E. lenta in 10/23 cases (43%). Mortality associated with E. lenta bacteremia was 22% (5/23). E. lenta bacteremia often occurred in patients with advanced cancer disease without documented infection. In most of the cases, intestinal obstruction and/or isolated fever were the only recorded symptoms. In these cases, the damages of intestinal barrier induced by the cancer and/or its specific treatments may be the cause of bacterial translocation.

Mathematical modeling of bacterial kinetics to predict the impact of antibiotic colonic exposure and treatment duration on the amount of resistant enterobacteria excreted.

Fecal excretion of antibiotics and resistant bacteria in the environment are major public health threats associated with extensive farming and modern medical care. Innovative strategies that can reduce the intestinal antibiotic concentrations during treatments are in development. However, the effect of lower exposure on the amount of resistant enterobacteria excreted has not been quantified, making it difficult to anticipate the impact of these strategies. Here, we introduce a bacterial kinetic model to capture the complex relationships between drug exposure, loss of susceptible enterobacteria and growth of resistant strains in the feces of piglets receiving placebo, 1.5 or 15 mg/kg/day ciprofloxacin, a fluoroquinolone, for 5 days. The model could well describe the kinetics of drug susceptible and resistant enterobacteria observed during treatment, and up to 22 days after treatment cessation. Next, the model was used to predict the expected amount of resistant enterobacteria excreted over an average piglet's lifetime (150 days) when varying drug exposure and treatment duration. For the clinically relevant dose of 15 mg/kg/day for 5 days, the total amount of resistant enterobacteria excreted was predicted to be reduced by 75% and 98% when reducing treatment duration to 3 and 1 day treatment, respectively. Alternatively, for a fixed 5-days treatment, the level of resistance excreted could be reduced by 18%, 33%, 57.5% and 97% if 3, 5, 10 and 30 times lower levels of colonic drug concentrations were achieved, respectively. This characterization on in vivo data of the dynamics of resistance to antibiotics in the colonic flora could provide new insights into the mechanism of dissemination of resistance and can be used to design strategies aiming to reduce it.

Trends in human fecal carriage of extended-spectrum ß-lactamases in the community: toward the globalization of CTX-M.

In the last 10 years, extended-spectrum ß-lactamase-producing enterobacteria (ESBL-E) have become one of the main challenges for antibiotic treatment of enterobacterial infections, largely because of the current CTX-M enzyme pandemic. However, most studies have focused on hospitalized patients, though today it appears that the community is strongly affected as well. We therefore decided to devote our investigation to trends in ESBL-E fecal carriage rates and comprehensively reviewed data from studies conducted on healthy populations in various parts of the world. We show that (i) community ESBL-E fecal carriage, which was unknown before the turn of the millennium, has since increased significantly everywhere, with developing countries being the most affected; (ii) intercontinental travel may have emphasized and globalized the issue; and (iii) CTX-M enzymes, especially CTX-M-15, are the dominant type of ESBL. Altogether, these results suggest that CTX-M carriage is evolving toward a global pandemic but is still insufficiently described. Only a better knowledge of its dynamics and biology will lead to further development of appropriate control measures.

Oral DAV131, a charcoal-based adsorbent, inhibits intestinal colonization by ß-lactam-resistant Klebsiella pneumoniae in cefotaxime-treated mice.

Antibiotics excreted into the intestinal tract, such as broad-spectrum cephalosporins, disrupt the indigenous microflora, affect colonization resistance (CR), and promote intestinal colonization by resistant bacteria. We tested whether oral DAV131, a charcoal-based adsorbent, would prevent colonization by a cefotaxime (CTX)-resistant Klebsiella pneumoniae strain (PUG-2) in CTX-treated mice. Mice received CTX, saline, CTX and DAV131, or saline and DAV131 for 3 days before oral challenge with 10(6) CFU of PUG-2. The fecal CTX concentrations and counts of PUG-2 were assayed. Fecal CTX disappeared when DAV131 was given concomitantly with CTX (P < 0.05), and the area under the curve of PUG-2 fecal density was significantly reduced (P < 0.01). In conclusion, reducing intestinal antibiotic exposure with DAV131 may reduce colonization by resistant strains during treatment compared to treatment with CTX only. This might open new possibilities for decreasing the impact of antibiotics on the intestinal microbiota during treatments.

Correlation between fecal concentrations of ciprofloxacin and fecal counts of resistant Enterobacteriaceae in piglets treated with ciprofloxacin: toward new means to control the spread of resistance?

We assessed in a piglet model the relationship between fecal ciprofloxacin concentrations and ciprofloxacin-resistant Enterobacteriaceae counts. Twenty-nine piglets were orally treated with placebo or with 1.5 or 15 mg ciprofloxacin/kg of body weight/day from day 1 (D1) to D5. Areas under the curve (AUC) of concentrations increased sharply with dose and correlated positively with AUC of resistant bacteria log counts between D1 and D9. Removing residual colonic quinolones could help to control the emergence of resistance in fecal flora.

International retrospective analysis of 73 cases of invasive fusariosis treated with voriconazole.

The outcomes for 73 invasive fusariosis patients treated with voriconazole were investigated. Patients with proven (n = 67) or probable (n = 6) infections were identified from the voriconazole clinical database (n = 39) and the French National Reference Center for Mycoses and Antifungals database (n = 34). Investigator-determined success was a complete or partial response. Survival was determined from day 1 of voriconazole therapy to the last day known alive. Patients were 2 to 79 years old (median, 43 years), and 66% were male. Identified Fusarium species (62%) were F. solani, F. moniliforme, F. proliferatum, and F. oxysporum. Underlying conditions analyzed included hematopoietic stem cell transplant (HSCT; 18%), hematologic malignancy (HM; 60%), chronic immunosuppression (CI; 12%), or other condition (OC; 10%). Infection sites were brain (5%), disseminated excluding brain (67%), lungs/sinus (15%), and other (12%). Most patients (64%) were or had recently been neutropenic (<500 cells/mm(3)). Therapy duration was 1 to 480 days (median, 57 days), with a 47% success rate. Baseline neutropenia impacted success adversely (P ≤ 0.03). Success varied by underlying condition (HSCT, 38%; HM, 45%; CI, 44%; OC, 71%) and infection site (brain, 0%; disseminated, 45%; other, 56%; lung/sinus, 64%) (P > 0.05). Combination therapy (13 patients) was no better than treatment with voriconazole alone. Overall, 59% of the patients died (49% died of fusariosis), and 90-day survival was 42%. Site of infection influenced survival (P = 0.02). Median survival (in days) by species was as follows: F. solani, 213; F. oxysporum, 112; Fusarium spp., 101; F. proliferatum, 84; F. moniliforme, 76. We conclude that voriconazole is a therapeutic option for invasive fusariosis.

Paradoxical High-Level Spiramycin Resistance and Erythromycin Susceptibility due to 23S rRNA Mutation in Streptococcus constellatus.

Objectives: The aim of the study was to characterize phenotypically and genotypically an uncommon mechanism of resistance to macrolides, lincosamides, and streptogramins (MLS) in a Streptococcus milleri group clinical isolate. Materials and Methods: The isolate UCN96 was recovered from an osteoradionecrosis wound, and was identified using the matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and the partial sequencing of the sodA gene. Antimicrobial susceptibility testing were carried out by the disk diffusion method and minimal inhibitory concentrations (MICs) were determined by the broth microdilution technique. PCR screening was performed for MLS resistance genes described in Gram-positive bacteria. Specific mutations in the ribosomal proteins L3-, L4-, and L22-encoding genes were also screened and those in domain V of the 23S rRNA gene (rrl). The number of mutated copies of the rrl gene was determined using amplification-refractory mutation system quantitative-polymerase chain reaction (qPCR) analysis. Results: The clinical isolate UCN96 was unambiguously identified as Streptococcus constellatus. It was susceptible to all macrolides and lincosamides (ML) antibiotics except spiramycin (MIC >256 mg/L) while it was also resistant to streptogramins. Screening for all acquired resistance genes was negative and no mutation was found in genes coding for L3, L4, and L22 ribosomal proteins. Of interest, a single mutation, A2062C (according to Escherichia coli numbering), was detected in the domain V of 23S rRNA. Conclusion: Mutations at the position 2062 of 23S rRNA have been detected once in Streptococcus pneumoniae, and not yet in other Streptococcus spp. This mechanism is very likely uncommon in Gram-positive bacteria because different copies of 23S rRNA operons should be mutated for development of such a resistance pattern.

Clonal population of flucytosine-resistant Candida tropicalis from blood cultures, Paris, France.

Candida tropicalis is a diploid ascomycetes yeast responsible for 4%-24% of candidemia. Resistance to flucytosine is rarely described for this species but was observed for 45 (35%) of 130 C. tropicalis isolates recovered from blood cultures in the Paris area in a 4-year survey. The aims of this study were to test the hypothesis that the flucytosine-resistant isolates could represent a subgroup and to determine the relationship between epidemiologic and genomic data. Epidemiologic data and gene sequences were analyzed, and molecular typing was performed. Our results suggest that a clone of flucytosine-resistant isolates, associated with malignancies and a lower mortality than that for other C. tropicalis isolates, is widespread in the Paris area. We propose the analysis of 2 polymorphic microsatellite markers coupled with URA3 sequencing to track the clone.

A Long-Term Study of the Diversity of OXA-48-Like Carbapenemase-Producing Bacterial Strains in Infected Patients and Carriers.

PURPOSE: Since their emergence at the beginning of the century, OXA-48 carbapenemases have spread in the community and in hospitals. To assess the diversity of OXA-48-producing bacterial strains and plasmids in the hospital setting, we studied the strains isolated from patients in three hospitals in the Paris area. MATERIALS AND METHODS: All possible OXA-48-like strains were included in the study. OXA-48-like and extended-spectrum beta-lactamase-encoding genes were identified, and fingerprinting analysis was performed for all Escherichia coli and Klebsiella pneumoniae strains. The backbones and close genetic environments of blaOXA-48 were assessed by amplifying genes that were specific to the pOXA-48a plasmid and PCR, encompassing the junctions between blaOXA-48 and its direct genetic environment. RESULTS: Overall, 68 strains from 30 patients were studied. These strains belonged to seven different enterobacterial species. OXA-48, OXA-204, and OXA-401 were identified in 62, 3, and 3 isolates, respectively. Additional broad-spectrum beta-lactamases were identified in 34% (23/68) of the strains. The strain diversity was high between and within patients. Identical patterns were observed only within individual patients or among epidemiologically related patients. Plasmid mapping was performed in the 62 OXA-48-producing strains and the 3 OXA-405-producing strains, resulting in the identification of 5 different patterns. CONCLUSION: Because of their ability to transfer between strains, OXA-48 carbapenemases have a high risk of dissemination and may become endemic in France.

Microbiological and physicochemical stability of fentanyl and sufentanil solutions for patient-controlled delivery systems.

The aim of this study was to assess the microbiological and physicochemical stability of opioid solutions containing fentanyl or sufentanil and thereby determine the feasibility of extending the expiration dates after mixing. Five systems containing fentanyl or sufentanil solutions at 50 microg/mL in portable patient-controlled analgesia (PCA) systems were filled and stored at room temperature for 14 days. They were sampled immediately after preparation, at day 3, and each day of the following weeks. Microbiological stability was assessed by performing sterility tests. The physicochemical study was performed by determining aspect, pH, and osmolality evolution. All samples were tested for appearance, change in color, and loss of concentration using an analytical method. There was no significant change in pH and osmolality values of any solutions. No precipitation or change in color was observed in any of the sample solutions. There was no significant loss of fentanyl or sufentanil over 14 days (4.3% and 4.1%, respectively). This study indicates that both drug solutions in the PCA systems are stable for a minimum of 14 days at room temperature.

Indwelling time and risk of infection of dialysis catheters in critically ill cancer patients.

OBJECTIVE: Despite the lack of evidence to support routine scheduled replacement of dialysis catheters (DCs) this practice continues to be widely used in many intensive care units (ICUs). This study evaluated whether additional risks of catheter-related infection (CRI) are incurred with a conservative attitude in critically ill cancer patients. DESIGN AND SETTING: Prospective, observational study over a 14-month period in a 15-bed medicosurgical unit in a comprehensive cancer center. PATIENTS: Seventy-nine double-lumen DCs were evaluated in 47 patients. Incidence rates of infection per 1000 days of catheter use were examined over 7-day periods. MEASUREMENTS AND RESULTS: The mean indwelling time was 6.9+/-5.5 days. Twelve DCs (15.2%) were removed for suspected CRI. Catheter-tip cultures remained negative in 74 cases (93.7%). Overall, one bacteremic CRI, two colonization episodes, and two contaminations were diagnosed, leading to DC colonization and DC-related bacteremia incidence rates of, respectively, 5.4 and 1.8 per 1000 days. When the catheter colonization rate was examined at 7-day intervals, the incidence rate was similar whatever the indwelling time: 5.8, 4.8, and 6.0 per 1000 days, respectively, for the 49 catheters left in place for 7 days or less, 8-14 days (21 DCs), and more than 14 days (9 DCs). The DC colonization incidence rate was similar to that of the 42 short-term catheters inserted during the same period in the same patients (5.9 per 1000 days). CONCLUSIONS: The stable low risk for DC-related infections over time does not support the rationale for scheduled replacement, even in immunocompromised cancer patients.

Monitoring antibiotic-resistant enterobacteria faecal levels is helpful in predicting antibiotic susceptibility of bacteraemia isolates in patients with haematological malignancies.

Delay of active antimicrobial therapy in haematological patients with Gram-negative bacilli bacteraemia during profound neutropenia exposes them to increased morbidity and mortality. The digestive tract is the main source of enterobacteria causing bacteraemia in these patients. We thus evaluated the usefulness of broad-spectrum beta-lactam resistant enterobacteria (BSBL-RE) faecal shedding assessment in forecasting the susceptibility to BSBLs of the strains isolated from blood cultures. From 2002 to 2011, neutropenic haematological patients with bacteraemia caused by enterobacteria who had a stool culture during the previous 7 days were retrospectively included. BSBL-RE intestinal carriers were compared with non-carriers in terms of clinical and microbiological criteria. One hundred and four patients were included and 16 of them (15.4 %) were BSBL-RE carriers. Multivariate analysis showed that BSBL-RE carriage was independently associated with BSBL-RE identified in blood cultures (P < 0.001) and the use of carbapenems as empirical treatment of the bacteraemia (P = 0.008). Sensitivity, specificity, and the positive and negative predictive values of the test were 80 %, 91 %, 50 % and 98 %, respectively. Among the carriers, those with the highest level of BSBL-RE carriage were also those with the highest risk of bacteraemia due to BSBL-RE (P < 0.001). Close monitoring of BSBL-RE intestinal carriage may help to choose the most appropriate initial antimicrobial treatment for neutropenic haematological patients with bacteraemia.

Anticancer immunotherapy by CTLA-4 blockade relies on the gut microbiota.

Antibodies targeting CTLA-4 have been successfully used as cancer immunotherapy. We find that the antitumor effects of CTLA-4 blockade depend on distinct Bacteroides species. In mice and patients, T cell responses specific for B. thetaiotaomicron or B. fragilis were associated with the efficacy of CTLA-4 blockade. Tumors in antibiotic-treated or germ-free mice did not respond to CTLA blockade. This defect was overcome by gavage with B. fragilis, by immunization with B. fragilis polysaccharides, or by adoptive transfer of B. fragilis-specific T cells. Fecal microbial transplantation from humans to mice confirmed that treatment of melanoma patients with antibodies against CTLA-4 favored the outgrowth of B. fragilis with anticancer properties. This study reveals a key role for Bacteroidales in the immunostimulatory effects of CTLA-4 blockade.

Treatment with piperacillin-tazobactam and false-positive Aspergillus galactomannan antigen test results for patients with hematological malignancies.

We report the occurrence of a high rate of false-positive test results during the surveillance of hematology patients for galactomannan (GM) antigenemia. Among 218 patients surveyed from June 2002 through June 2003, 42 (19.3%) had > or =1 serum sample positive for GM (optical density index, >1.5). Of these patients, 38 had no additional evidence of invasive aspergillosis, and, therefore, their test results were considered to be false-positives. Case-control analysis showed that treatment with piperacillin-tazobactam was the only risk factor significantly associated with receiving false-positive test results. When tested for GM antigen, 3 of 4 piperacillin-tazobactam batches had positive results. Physicians should be aware of the possible interference of treatment with piperacillin-tazobactam when interpreting the results of the GM assay.