Species and antimicrobial susceptibility testing of coagulase-negative staphylococci in periprosthetic joint infections.

The objective was to evaluate the distribution of coagulase-negative staphylococci (CNS) involved in periprosthetic-joint infections (PJIs) and to describe their susceptibility profile to antibiotics. We conducted a multicentre retrospective study in France, including 215 CNS PJIs between 2011 and 2015. CNS PJIs involved knees in 54% of the cases, hips in 39%, other sites in 7%. The distribution of the 215 strains was: Staphylococcus epidermidis 129 (60%), Staphylococcus capitis 24 (11%), Staphylococcus lugdunensis 21 (10%), Staphylococcus warneri 8 (4%), Staphylococcus hominis 7 (3%), Staphylococcus haemolyticus 7 (3%). More than half of the strains (52.1%) were resistant to methicillin, 40.9% to ofloxacin, 20% to rifampicin. The species most resistant to antibiotics were S. hominis, S. haemolyticus, S. epidermidis, with 69.7% of the strains resistant to methicillin and 30% simultaneously resistant to clindamycin, cotrimoxazole, ofloxacin and rifampicin. No strain was resistant to linezolid or daptomycin. In this study on CNS involved in PJIs, resistance to methicillin is greater than 50%. S. epidermidis is the most frequent and resistant species to antibiotics. Emerging species such S. lugdunensis, S. capitis and Staphylococcus caprae exhibit profiles more sensitive to antibiotics. The antibiotics most often active in vitro are linezolid and daptomycin.

Characteristics of Enterobacter cloacae prosthetic joint infections.

OBJECTIVES: Enterobacter cloacae prosthetic joint infections (PJI) are rare and poorly documented. PATIENTS AND METHODS: We conducted a retrospective and monocentric study in an orthopedic unit supporting complex bone and joint infections. Between 2012 and 2016 we collected background, clinical, biological, and microbiological data from 20 patients presenting with prosthetic joint infection and positive for E. cloacae, as well as data on their surgical and medical treatment and outcome. RESULTS: Infections were localized in the hip (n=14), knee (n=5), or ankle (n=1). The median time between arthroplasty and septic revision was three years. Fourteen patients (70%) had undergone at least two surgeries due to previous prosthetic joint infections. The median time between the last surgery and the revision for E. cloacae infection was 31 days. Eleven patients (55%) were infected with ESBL-producing strains. The most frequently used antibiotics were carbapenems (n=9), cefepime (n=7), quinolones (n=7), and fosfomycin (n=4). The infection was cured in 15 patients (78.9%) after a 24-month follow-up. Five patients had a recurrent infection with another microorganism and four patients had a relapse of E. cloacae infection. The global success rate was 52.7% (58.3% for DAIR and 75% for DAIR+ciprofloxacin). CONCLUSION: Prosthetic joint infections due to E. cloacae usually occur early after the last prosthetic surgery, typically in patients with complex surgical and medical histories. The success rate seems to be increased when DAIR is associated with ciprofloxacin.

[Interest of admission blood sampling for the detection of somatic comorbidity in hospitalized psychiatric patients]. / Intérêt du bilan biologique d'entrée dans le dépistage de comorbidités chez les patients hospitalisés en psychiatrie.

INTRODUCTION: Elevated prevalence of somatic disorders among psychiatric patients is well known and studied since latest years. According to several studies, all-cause death risk is three to fivefold to that in the general population, and a somatic comorbidity was found in 30 to 60% of patients hospitalized in a psychiatric hospital, but was unknown in 50% of cases. OBJECTIVE: Our aim was to evaluate the interest of admission blood sampling analyses for the detection of somatic comorbidity, such as impaired glucose tolerance, diabetes mellitus, lipid abnormalities or infectious diseases among hospitalized psychiatric patients. DESIGN: During three months, laboratory tests (blood cell count, glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, sodium, potassium, chlorine, urea, creatinine, alanine aminotransferase, aspartate aminotransferase, gamma glutamyltransferase, alkaline phosphatase, and TSH) were determined in admission blood samples from 366 patients of two psychiatric hospitals. Then, according to the blood results, other biological tests (iron, ferritin, etc.) were made. RESULTS: For 194 of the 366 blood samples included (53%), at least one biological abnormality was detected. Moreover, variations in haematological variables, glucose and lipid concentrations were the most frequent. We found that 45 (10.6%) of the patients had impaired glucose tolerance (glycaemia > or =1.10 g/l), 21 (5.7%) had glycaemia > or =1.26 g/l, and 76 (23%) had dyslipidemia (HDL-cholesterol < or =0.40 g/l, LDL-cholesterol > or =1.60 g/l, or triglycerides > or =1.50 g/l). None of them had used glucose or cholesterol lowering drugs before the blood sampling. Furthermore, low haemoglobin concentrations were detected in 34 patients (9.3%) and high white cell counts (above 12 g/l) in 26 patients (7.1%). CONCLUSION: Despite methodological limits, these results showed the frequency of somatic comorbidity in patients hospitalized in psychiatric hospitals. Thus, admission blood sampling would be likely to improve the detection of somatic disorders, such as diabetes mellitus, dyslipidemia, or infectious diseases.

Staphylococcus lugdunensis, a serious pathogen in periprosthetic joint infections: comparison to Staphylococcus aureus and Staphylococcus epidermidis.

OBJECTIVES: The aim of this study was to assess the characteristics of periprosthetic joint infection (PJI) due to Staphylococcus lugdunensis and to compare these to the characteristics of PJI due to Staphylococcus aureus and Staphylococcus epidermidis. METHODS: A retrospective multicentre study including all consecutive cases of S. lugdunensis PJI (2000-2014) was performed. Eighty-eight cases of staphylococcal PJI were recorded: 28 due to S. lugdunensis, 30 to S. aureus, and 30 to S. epidermidis, as identified by Vitek 2 or API Staph (bioMérieux). RESULTS: Clinical symptoms were more often reported in the S. lugdunensis group, and the median delay between surgery and infection was shorter for the S. lugdunensis group than for the S. aureus and S. epidermidis groups. Regarding antibiotic susceptibility, the S. lugdunensis strains were susceptible to antibiotics and 61% of the patients could be treated with levofloxacin + rifampicin. The outcome of the PJI was favourable for 89% of patients with S. lugdunensis, 83% with S. aureus, and 97% with S. epidermidis. CONCLUSION: S. lugdunensis is an emerging pathogen with a pathogenicity quite similar to that of S. aureus. This coagulase-negative Staphylococcus must be identified precisely in PJI, in order to select the appropriate surgical treatment and antibiotics .

Is Xpert MRSA/SA SSTI real-time PCR a reliable tool for fast detection of methicillin-resistant coagulase-negative staphylococci in periprosthetic joint infections?

Periprosthetic joint infections (PJIs) are frequently caused by methicillin-resistant coagulase-negative staphylococci (CoNS). Cultures remain the gold standard but often require a few days. Thus, a rapid test could be interesting to guide antibiotic strategy earlier. The purpose of this study was to evaluate the performances of RT-PCR Xpert® MRSA/SA technique for the detection of methicillin-resistant CoNS (MRCoNS) from deep samples in patients with PJIs. RT-PCR was tested on 72 samples. Sensitivity, specificity, positive predictive value, and negative predictive value of RT-PCR method were 0.36, 0.98, 0.90, and 0.74, respectively. Although RT-PCR may allow early microbial diagnosis of PJI due to Staphylococcus aureus (MSSA and MRSA), the low sensitivity and the high cost of this method to detect MRCoNS could limit its use in this field.

[Knowledge of nursing students about occupational biological risk]. / Conoscenze degli allievi infermieri sul rischio biologico occupazionale.

The health care staff is potentially more exposed to contract infectious diseases at work. This risk becomes true if the DPI are not utilized and the operators don't work according to the standard protocol, and, with regard to the health care students, they begin their clinical training without the right knowledges. To verify the adequacy of knowledges and the consequent behaviours we effected a study among the students at first year of the D. U. for nurses in the University of L'Aquila, through a questionnaire. It came out many gaps of knowledges about the standard practice and about the Universal Precautions in about 20% of the interviewed.

Viridans streptococcal bacteraemia in patients with neutropenia.

Viridans streptococcal bacteraemia is frequent in neutropenic patients. 25 neutropenic patients with viridans streptococcal bacteraemia were compared with 64 control patients. Exposure to repeated chemotherapy or cytarabine were independent risk-factors for streptococcal bacteraemia. The use of carboxyureidopenicillins and a stay in laminar-airflow rooms were protective. In a further cohort study of 49 patients, oral streptococci with the same ribotype as blood isolates were recovered from all 7 bacteraemic patients. The oral cavity is a portal of entry for viridans streptococci bacteraemia in neutropenic patients, especially after oral mucosal damage induced by repeated chemotherapy.