Evaluation of the MRSA/SA ELITe MGB Assay for the Detection of Staphylococcus aureus in Bone and Joint Infections.

Bone and joint infections represent a potentially devastating complication of prosthetic orthopedic joint replacement, thus requiring both rapid and appropriate antibiotic treatment. Staphylococcus aureus is one of the most common pathogens involved in this pathology. Being able to assert its presence is the first step of efficient patient management. This monocenter study evaluated the MRSA/SA ELITe MGB assay for the molecular detection of S. aureus and methicillin-resistant S. aureus (MRSA) in bone and joint biopsy specimens and synovial fluids. This test, together with conventional techniques, including standard cultures and the 16S rRNA amplification assay, was performed on 208 successive perioperative samples collected prospectively for 1 year obtained from 129 patients. Using conventional techniques, we detected a microbial pathogen in 76 samples from 58 patients, 40 of which were identified as S. aureus. The limit of detection (LOD) of the MRSA/SA ELITe MGB assay was experimentally determined for bone and joint biopsy specimens and synovial fluids using negative samples spiked with S. aureus ATCC 43300. The sensitivities of S. aureus detection with the MRSA/SA ELITe MGB assay were 82.5% (33/40 samples) and 97.5% (39/40 samples) using the manufacturer's LOD and an experimentally determined LOD, respectively. Interestingly, using the osteoarticular specific LOD, 15 additional samples were determined to be positive for S. aureus DNA with the MRSA/SA ELITe MGB assay; in all cases, these samples were obtained from patients considered to be infected with S. aureus according to their clinical and microbiological records. The results were available within 24 h, which could help to expedite therapeutic decisions.

Duration of rifampin therapy is a key determinant of improved outcomes in early-onset acute prosthetic joint infection due to Staphylococcus treated with a debridement, antibiotics and implant retention (DAIR): a retrospective multicenter study in France.

Introduction: In patients undergoing a « debridement, antibiotics, and implant retention ¼ (DAIR) procedure for acute staphylococcal prosthetic joint infection (PJI), post-operative treatment with rifampin has been associated with a higher probability of success.(1,2) However, it is not known whether it is the total dose, delay of introduction or length of therapy with rifampin that is most strongly associated with the observed improved outcomes. Methods: A multicentric, retrospective cohort study of patients with acute staphylococcal hip and knee PJI treated with DAIR between January 2011 and December 2016. Failure of the DAIR procedure was defined as persistent infection, need for another surgery or death. We fitted logistic and Cox regression multivariate models to identify predictors of DAIR failure. We compared Kaplan-Meier estimates of failure probability in different levels of the 3 variables of interest - total dose, delay of introduction or length of therapy with rifampin - with the log-rank test. Results: 79 patients included (median age 71 years [63.5-81]; 55 men [70%]), including 54 (68%) DAIR successes and 25 (32%) DAIR failures. Patients observed for a median of 435 days [IQR 107.5-834]. Median ASA score significantly lower in DAIR successes than in DAIR failures (2 vs. 3, respectively p = 0.011). Bacterial cultures revealed 65 (82.3%) S. aureus and 16 (20.3%) coagulase negative staphylococci, with 2 patients being infected simultaneously with S. aureus and CNS. Among S. aureus isolates, 7 (10.8%) resistant to methicillin; 2 (3.1 %) resistant to rifampin. Median duration of antimicrobial therapy was 85 days [IQR 28.5-97.8]. Fifty-eight patients (73.4%) received rifampin at a median dose of 14.6 mg/kg/day |IQR 13-16.7], started at a median delay of 8.5 days [IQR, 4-7.5] after debridement surgery. Twenty-one patients (26.6%) developed a drug-related adverse event, leading to rifampin interruption in 6 of them (7.6% of total cohort). Determinants of DAIR failure were rifampin use (HR 0.17, IC [0.06, 0.45], p-value <0.001), association of rifampin with a fluoroquinolone (HR 0.19, IC [0.07, 0.53], p-value = 0.002) and duration of rifampin therapy (HR 0.97, IC [0.95, 1], p-value = 0.022). We did not observe a significant difference between DAIR successes and failures in rifampin use, dose and delay of introduction. In a multivariate Cox model, only duration of rifampin therapy was significantly associated with DAIR failure. Kaplan Meier estimate of DAIR failure probability was significantly higher in patients receiving less than 14 days of rifampin in comparison with those receiving more than 14 days of rifampin (p = 0.0017). Conclusion: Duration of rifampin therapy is a key determinant of improved outcomes in early-onset acute prosthetic joint infection due to Staphylococcus treated with DAIR.

Acute kidney injury in infective endocarditis: A retrospective analysis.

BACKGROUND: Acute kidney injury (AKI) is associated with high case fatality in infective endocarditis (IE), but epidemiological data on the frequency of AKI during IE is scarce. We aimed to describe the frequency and risk factors for AKI during the course of IE using Kidney Disease: Improving Global Outcomes consensual criteria. METHODS: Using the French hospital discharge database (French acronym PMSI), we retrospectively reviewed the charts of 112 patients presenting with a first episode of probable or definite IE between January 2010 and May 2015. RESULTS: Seventy-seven patients (68.8%) developed AKI. In univariate analysis, risk factors for AKI were cardiac surgery for IE (n=29, 37.7% vs. n=4, 1.4%, P<0.0005), cardiac failure (n=29, 36.7% vs. n=1, 2.9%, P<0.0005), diabetes mellitus (n=14, 18.2% vs. n=1, 0.9%, P=0.034), and prosthetic valve IEs (n=24, 31.2% vs. n=4, 11.4%). No differences were observed for gentamicin exposure (n=57, 64% vs. n=32, 86.5%, P=0.286). Prosthetic valve IE, cardiac failure, and vancomycin exposure were independently associated with AKI with respective odds ratio of 5.49 (95% CI 1.92-17.9), 4.37 (95% CI 4.37-465.7), and 1.084 (1.084-16.2). Mean length of hospital stay was significantly longer in patients presenting with AKI than in controls (respectively 52.4±22.1 days vs. 39.6±12.6, P<0.005). CONCLUSION: AKI is very frequent during IE, particularly in patients with prosthetic valve IE, cardiac failure, and those receiving vancomycin.

CKD-EPI equation: A suitable Glomerular Filtration Rate estimate for drug dosing in HIV-infected patients.

OBJECTIVES: To evaluate concordance between glomerular filtration rate (GFR) estimates (Cockcroft and Gault, modification of diet in renal diseases, chronic kidney disease epidemiology study group equations) for drug dosing in HIV-infected patients. PATIENTS AND METHODS: We performed a monocentric study. GFR was measured using the gold standard method (plasma clearance of iohexol) in 230 HIV-infected patients. Concordance rate was evaluated between measured GFR (mGFR) and estimated GFR (eGFR) for different GFR categories (GFR>90 mL/min, GFR<90 mL/min, GFR>70 mL/min, and GFR<70 mL/min). MDRD and CKD-EPI were used with and without indexation to body surface area (BSA). RESULTS: Mean age was 48±10 years, mean mGFR was 101±26 mL/min. Concordance between mGFR and eGFR estimated with CG, CKD-EPI (indexed and not indexed to BSA), or MDRD equations (not indexed to BSA) was similar (73%, 73%, 74%, and 73% respectively) for a breakpoint value of 90 mL/min for GFR. At this value, the concordance rate between mGFR and MDRD indexed to BSA was significantly lower (65%, P<0.05). Using 70 mL/min of GFR as the breakpoint value, all equations had similar concordance rates with mGFR (with or without indexation to BSA). CONCLUSION: CKD-EPI equation has the same concordance with GFR and with CG when used for drug dosing.

Is nasal carriage of Staphylococcus aureus the main acquisition pathway for surgical-site infection in orthopaedic surgery?

The endogenous or exogenous origin of Staphylococcus aureus, responsible for orthopaedic surgical-site infections (SSI), remains debated. We conducted a multicentre prospective cohort study to analyse the respective part of exogenous contamination and endogenous self-inoculation by S. aureus during elective orthopaedic surgery. The nose of each consecutive patient was sampled before surgery. Strains of S. aureus isolated from the nose and the wound, in the case of SSI, were compared by antibiotypes or pulsed-field gel electrophoresis (PFGE). A total of 3,908 consecutive patients undergoing orthopaedic surgery were included. Seventy-seven patients developed an SSI (2%), including 22 related to S. aureus (0.6%). S. aureus was isolated from the nose of 790 patients (20.2%) at the time of surgery. In the multivariate analysis, S. aureus nasal carriage was found to be a risk factor for S. aureus SSI in orthopaedic surgery. However, only nine subjects exhibiting S. aureus SSI had been found to be carriers before surgery: when compared, three pairs of strains were considered to be different and six similar. In most cases of S. aureus SSI, either an endogenous origin could not be demonstrated or pre-operative nasal colonisation retrieved a strain that was different from the one recovered from the surgical site.

Q fever osteoarticular infection: four new cases and a review of the literature.

Q fever is a worldwide-occurring zoonosis caused by Coxiella burnetii. Better knowledge of the disease and of evolving diagnostics can enable recognition of unusual manifestations. Reported here are four cases of Q fever osteoarticular infections in adults: two cases of Q fever tenosynovitis, which represent the first two reports of this infection, and two cases of Q fever spondylodiscitis complicated by paravertebral abscess. In addition, the literature is reviewed on the 15 previously reported cases of Q fever osteoarticular infection, six of which were vertebral infections. Osteomyelitis is the usual manifestation Q fever osteoarticular infection. Because its onset is frequently insidious, diagnosis is usually delayed. The main differential diagnosis is mycobacterial infection, based on the histological granulomatous presentation of lesions. Whereas serology is the reference diagnostic method for Q fever, detection of C. burnetii in tissue specimens by PCR and cell culture provides useful additional evidence of infection. Culture-negative osteoarticular samples with granulomatous presentation upon histological examination should raise suspicion of Q fever.

Arthroplastic and osteosynthetic infections due to Propionibacterium acnes: a retrospective study of 52 cases, 1995-2002.

The cases of 52 patients with Propionibacterium acnes infection of orthopaedic implants are summarized: 20 patients with definite infection (sepsis, with P. acnes recovered from multiple specimens per patient), 15 with probable infection (sepsis, with P. acnes recovered from one specimen), and 17 with possible infection (signs of prosthetic malfunction or pseudo-osteoarthritis, with P. acnes recovered from one specimen). The patient population consisted of 37 males and 15 females with a mean age of 51.8 years (range 17-88). Besides bone surgery, 21% of these patients had severe coexisting illness. The study population was very heterogeneous and clinical presentation very polymorphic; infections became clinically apparent through sepsis, prosthetic malfunction, or a delay in consolidation. The diagnosis was highly dependent on the quality of the samples taken and the methodology used by the microbiology laboratory to isolate this bacterium. Culture time was long, on average 11.4 days. Treatment involved a combination of antibiotic treatments (67% of cases) and ablation of the material (83% of cases). Although P. acnes is considered to be weakly pathogenic, this bacterium may be responsible for infections in patients with implanted orthopaedic material. Ablation of the arthroplastic or osteosynthetic material is necessary in the majority of cases.

[Infectious complications and misuse of high-dose buprenorphine]. / Complications infectieuses et mésusage de la buprénorphine à haut dosage.

BACKGROUND: High-dose buprenorphine (HDB) treatment began in France in 1996 according to relatively unrestricted prescription rules. Continued heroin injection by patients on HDB maintenance treatment and even HDB injection remain underestimated and may lead to a variety of infectious diseases. OBJECTIVES: Description of infectious complications occurring in patients receiving HDB maintenance treatment. METHODS: Retrospective study of drug addicts receiving HDB maintenance treatment, injecting (or highly suspected of injecting) it, and hospitalized for infections (other than HIV or viral hepatitis) in the department of infectious and tropical diseases in Nancy University Hospital. Data collection covered 1998 through 2003. RESULTS: We identified 21 case reports, 9 concerning infectious endocarditis, 8 cutaneous abscesses, 2 osteoarticular infections, 1 meningitis and 1 Candida retinitis. The sex-ratio was of 1 woman for 2 men, and the patients' mean age was 29.8 years. Globally 13 patients had systemic infections. Nine patients admitted having injected HDB (and no other drugs) (including the case of Candida retinitis), while in the other 12 cases, the patients continued injecting heroin as well. The role of misused HDB was strongly suspected in those 12 infections, but was not clearly confirmed. All patients recovered from the infections. The long-term psychosocial outcome remains unknown. CONCLUSION: The cases analyzed illustrate the dual reality that HDB is often ineffective as a maintenance treatment, since some patients continue to inject heroin, and that its misuse can have infectious consequences. The results of HDB maintenance treatment substitution are mixed. The individual benefit/risk ratio must be improved. Networking is crucial, notably between physician and pharmacist, and the monitoring system must be reinforced.

[What data is needed today to deal with cellulitis and necrotizing fasciitis?]. / De quelles données a-t-on besoin aujourd'hui pour prendre en charge les cellulites et fasciites nécrosantes?

Cellulitis and necrotizing fasciitis can be distinguished by the depth of the cutaneous lesion and classically by the different bacteria implicated. This classification is not taken into account by the practitioner because of a similar therapeutic strategy. That is why most authors used a single title: necrotizing soft tissue infection. The potential severity of these infections required a quick diagnosis to decrease the risk of mortality and severe functional consequences. The analysis of the literature doesn't allow to establish the incidence of these infections. It was demonstrated that infections due to Streptococcus serogroup A increased over the last few years, thanks to a specific surveillance system. Risk factors leading to these infections are: cutaneous trauma, age, diabetes, varicella in children, contact with people infected by Streptococcus. The most recent studies demonstrated a frequent polymicrobism of the infections, with anaerobes, Streptococcus, Staphylococcus, and gram-negative rods. At the onset of the disease, the diagnosis is difficult to establish. Pain, induration of tissues, a rapid evolution, the inefficacy of antibiotic treatment suggest the diagnosis of necrotizing infection. MRI, when available, is a good technique to reveal the depth of the infection and necrosis. Surgery will confirm the diagnosis and allow for debridement of necrotized tissues. A delayed surgery increases the mortality risk factor, as stated in numerous studies.

[Factors associated with survival in Kaposi's sarcoma in patients infected with the human immunodeficiency virus. Clinical Epidemiological Group for AIDS in Aquitaine]. / Facteurs associés à la survenue de la maladie de Kaposi chez les patients infectés par le virus de l'immunodéficience humaine. Groupe d'Epidémiologie Clinique du SIDA en Aquitaine (GECSA).

BACKGROUND: To study behavioral risk factors of Kaposi's sarcoma (KS) among HIV infected homosexuals in Bordeaux, southwest France. METHODS: A case-control study was performed within the Aquitaine Cohort. Cases of KS surviving in 1995 and homosexuals were systematically enrolled. For each case, two controls were selected among homosexuals surviving in the cohort. Cases and controls were matched on year of diagnosis of HIV infection. Data collection was based on a self administered questionnaire focusing on use of recreational drugs, detailed sexual practices and sexually transmitted diseases in the year preceeding the diagnosis of HIV infection, in the year after the HIV diagnosis and in the year preceeding the diagnosis of KS (or an equivalent period of time for controls). RESULTS: Twelve cases were matched to 2 controls, 15 cases to one control and 13 cases remained unmatched. Matched analysis identified an association between KS and regular sexual partner (odds ratio = 0.07; 95% confidence interval: 0.01-0.52 and p < 0.001) and active and passive oro-anal intercourse before HIV diagnosis and before KS diagnosis (p = 0.01). In the unmatched analysis including all cases, we found an association between KS and the overall number of sexual partners (p < 0.03) for all periods of interest. CONCLUSIONS: This case-control study identified sexual practices in favor of a sexually transmitted agent of KS.

Incidence of acquired immunodeficiency syndrome (AIDS)-related Kaposi's sarcoma in the Aquitaine Cohort, France, 1988-1996. Groupe d'Epidémiologie Clinique du SIDA en Aquitaine.

OBJECTIVE: To assess secular trends of the incidence of Kaposi's sarcoma (KS) between 1988 and 1996 in the Aquitaine Cohort of human immunodeficiency virus type 1 (HIV1)-infected subjects (southwestern France). METHODS: Adults of both sexes of all HIV-transmission categories were included. We distinguished between incident and prevalent KS and in case of multiple acquired immunodeficiency syndrome (AIDS) defining illnesses between initial or subsequent KS. Only incident KS were considered for annual incidence rate calculation. RESULTS: Overall, 21.2% (356/1678) of homosexuals and 1.9% (58/3030) of the other patients were diagnosed with KS over time. Although there was a sharp decrease in 1996 for initial KS, the annual incidence rate of KS was stable over time in the overall cohort as well as in homosexuals (4.3% per year on the average for KS as an initial AIDS-defining illness and 2.1% per year for subsequent KS in homosexuals). The median CD4+ cell count at the time of diagnosis of KS was 56 per mm3 (78 for initial KS, 14 for subsequent KS), with no significant variation over time. CONCLUSION: In the Aquitaine Cohort, the annual incidence of KS has remained stable between 1988 and 1995 with a recent decline in 1996, only for initial KS, while case management of HIV-infected subjects changed drastically.

Acquired immunodeficiency syndrome-associated Kaposi's sarcoma and human herpesvirus 8 DNA detection in serial peripheral blood mononuclear cell samples.

Human herpesvirus 8 (HHV8) DNA was amplified from peripheral blood mononuclear cells (PBMCs) using PCR in 120 HIV-seropositive in- and outpatients who were enrolled in a cohort study between January 1994 and June 1995. Risk factors for HIV infection were homosexuality/bisexuality alone in 64 cases (30 with Kaposi's sarcoma (KS) and 34 without KS, 4 of whom had KS lesions that appeared during follow-up in the cohort), heterosexual contact alone in 32 cases (among whom 1 woman with KS who was the spouse of a bisexual with KS), and transfusion of blood or blood products alone in 24 cases. Three blood samples at 3-4-month intervals were scheduled for each patient. Twenty-five HIV1-seronegative patients served as controls. A total of 47.1% of homo- or bisexual males with KS and 26.7% of homo- or bisexual males without KS had positive HHV8 DNA detection as compared with 21.9% of patients contaminated by heterosexual contact, 8.3% of blood product recipients and 0% of controls. HHV8 DNA detection was intermittent in all but 3 patients according to sequential sampling. Multivariate analysis showed that AIDS-KS was associated with sexual transmission, mainly homo- or bisexual practices and with HHV8 infection assessed by PCR in PBMCs.

Massive haemorrhage from rupture of a pancreatic pseudocyst after pentamidine-associated pancreatitis.

A 40 year-old man with the acquired immunodeficiency syndrome who was treated with intravenous pentamidine suffered a massive spontaneous haemorrhage caused by rupture of a pancreatic pseudocyst after pentamidine-induced pancreatitis. The patient previously presented symptomatic hypoglycaemia, severe nephrotoxicity and hyperkalaemia, while not receiving any other drug but pentamidine. This is the first case reported of such a complication of pentamidine induced pancreatitis, and one of the few cases reported of the latter adverse event.