Comparison of the in vitro activities of delafloxacin and comparators against Staphylococcus epidermidis clinical strains involved in osteoarticular infections: a CRIOGO multicentre retrospective study.

OBJECTIVES: Staphylococcus epidermidis bone and joint infections (BJIs) on material are often difficult to treat. The activity of delafloxacin has not yet been studied on S. epidermidis in this context. The aim of this study was to assess its in vitro activity compared with other fluoroquinolones, against a large collection of S. epidermidis clinical strains. METHODS: We selected 538 S. epidermidis strains isolated between January 2015 and February 2023 from six French teaching hospitals. One hundred and fifty-two strains were ofloxacin susceptible and 386 were ofloxacin resistant. Identifications were performed by MS and MICs were determined using gradient concentration strips for ofloxacin, levofloxacin, moxifloxacin and delafloxacin. RESULTS: Ofloxacin-susceptible strains were susceptible to all fluoroquinolones. Resistant strains had higher MICs of all fluoroquinolones. Strains resistant to ofloxacin (89.1%) still showed susceptibility to delafloxacin when using the Staphylococcus aureus 2021 CA-SFM/EUCAST threshold of 0.25 mg/L. In contrast, only 3.9% of the ofloxacin-resistant strains remained susceptible to delafloxacin with the 0.016 mg/L S. aureus breakpoint according to CA-SFM/EUCAST guidelines in 2022. The MIC50 was 0.094 mg/L and the MIC90 was 0.38 mg/L. CONCLUSIONS: We showed low delafloxacin MICs for ofloxacin-susceptible S. epidermidis strains and a double population for ofloxacin-resistant strains. Despite the absence of breakpoints for S. epidermidis, delafloxacin may be an option for the treatment of complex BJI, including strains with MICs of ≤0.094 mg/L, leading to 64% susceptibility. This study underlines the importance for determining specific S. epidermidis delafloxacin breakpoints for the management of BJI on material.

Cutibacterium namnetense osteosynthetic cervical spine infections: experience with two cases.

We report two uncommon cases of osteosynthetic cervical spine infection. Clinical patient features, microbiological strain characteristics, diagnostic methods, and treatment were analyzed. Both patients were male, and one had risk factors for surgical site infection. During surgery, perioperative samples were positive yielding an anaerobic microorganism identified as Cutibacterium namnetense by MALDI-TOF MS and confirmed by 16S rRNA/gyrB genes sequencing. All isolates were fully susceptible. C. namnetense osteosynthetic cervical spine infections are rare. Both cases were early surgical site infections. Bruker MALDI-TOF MS appears to be an excellent tool for rapid and accurate identification. Amoxicillin seems to be an option for the treatment.

Development and evaluation of automated synovial fluid total cell count on an Iris iQ® 200 for identifying patients at risk of septic arthritis.

Septic arthritis is a diagnostic emergency. The white blood cell (WBC) count, in synovial fluid (SF), can guide the diagnosis. From November 2021 to November 2022, we included 350 SF. The WBC count was performed with the Iris iQ® 200 compared with the manual method. Automated and manual counts displayed good correlation. However, a Bland Altman plot demonstrates a higher percentage difference at higher WBC counts. The use of Iris iQ® 200 for SF analysis enables a rapid and accurate assessment for WBC count. Its implementation would advantageously replace the long and tedious optical analysis in daily routine.

Assessment of the Performance of the Aptima Bacterial Vaginosis Assay Over a 3-Month Period in a French Hospital.

Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge. BV represents a dysbiosis with the acquisition of a diverse community of anaerobic bacteria and a reduction in lactobacilli burden. Our objective was to evaluate the Aptima BV assay kit for the diagnosis of BV. From May to August 2019, we enrolled outpatients and inpatients, including nonpregnant women above 18 with vaginosis symptoms, consulting at Nantes University hospital. The Aptima BV assay measures the loads of Gardnerella vaginalis, Atopobium vaginae, and Lactobacillus species in relation to overall bacterial load. The Aptima BV assay was compared to Nugent scoring (NS). A total of 456 women were enrolled, and 347 patients met the inclusion criteria with data available for the analysis. NS was used to classify the samples and 144 (41.5%) samples were classified as normal (NS = 0-3), 45 (13%) as BV (NS = 7-10), 38 (11%) presented an intermediate vaginal microbiota (3 < NS < 7), 79 (22.7%) had various bacteria (excluding vaginal flora), 29 (8.3%) had insufficient bacterial density, and 12 (3.5%) had a predominance of yeasts. The Aptima BV kit displayed a sensitivity of 91.1% and specificity of 94.4% with a positive predictive value (PPV) of 83.7% and a negative predictive (NPV) value of 97.1%. The results of this monocentric retrospective study show that Aptima BV kit has a good diagnostic correlation compared to standard of care for dysbiotic diagnosis cases. IMPORTANCE The possibility exists of the involvement of a new molecular test in the routine algorithm of bacterial vaginosis diagnosis in microbiology laboratories. This manuscript reports on our experience, and we propose an organization combining Nugent scoring and molecular testing, especially for intermediate Nugent scores.

Epidemiology and clinical characteristics of Klebsiella spp. meningitis in France.

OBJECTIVES: To describe the epidemiology of Klebsiella spp. meningitis in France with respect to clinical and bacteriological data. METHODS: We performed a four-year multicenter, retrospective, observational study. The primary objective was to provide a clinical description of patients with Klebsiella spp. meningitis. Secondary objectives were to compare community-acquired meningitis and healthcare-associated meningitis and to analyze factors associated with mortality. RESULTS: We enrolled 131 patients with Klebsiella spp. meningitis. Eighty-two (62.6%) infections were reported following neurosurgery. Twenty-eight strains (21.4%) were resistant to third-generation cephalosporins (3GC). The median [IQR] cellularity was 980/mm3 [116-5550], the median protein level was 5.67 [1.62-9] g/L and the median CSF glucose level was 2.5 [0-3.4] mmol/L. The in-hospital mortality rate was 23.6%. Community-acquired meningitis isolates were more frequently susceptible to 3GC than isolates from healthcare-associated meningitis (89.2% versus 72%; P=0.04). Comorbidities reported for patients with community-acquired meningitis were mainly diabetes mellitus and liver cirrhosis. In multivariate analysis, focal neurological disorder at the time of diagnosis was the only factor associated with in-hospital mortality (P=0.01). CONCLUSIONS: Purulent meningitis caused by Klebsiella spp. needs to be considered in patients with community-acquired meningitis and preexisting conditions, as well as in case of meningitis following neurosurgical procedures.

Low prevalence of Cutibacterium acnes in prostatic tissue biopsies in a French hospital.

We evaluated the Cutibacterium acnes prevalence in prostatic biopsies and characterized the strains at a molecular level. 18 out of 36 biopsies (50%) were sterile after seven days in culture. C. acnes was observed in only two biopsies. Its prevalence was low (5.6%). Finally, the molecular characterization revealed diverse clusters including phylotypes IA1, IB and II.

Misidentification of Cutibacterium namnetense as Cutibacterium acnes among clinical isolates by MALDI-TOF VitekMS: usefulness of gyrB sequencing and new player in bone infections.

The taxonomy modification of Propionibacterium sp. with the description of new species, especially Cutibacterium namnetense, raises the question of species distribution in routine clinical samples. We performed a retrospective study during 3 years before the implementation of MALDI-TOF. Two hundred sixty-nine isolates were included in the study. MALDI-TOF identification, 16S rRNA, and new developed gyrB partial sequencings were performed. The most representative species was C. acnes in 88% of the cases, regardless of the origin of the clinical sample. Eventually, we identified three C. namnetense strains, representing a 1.1% prevalence over the period of time, including two bone infections. MALDI-TOF databases should be regularly updated to incorporate new species. gyrB sequencing constitutes a both easy and relevant method to identify Cutibacterium sp. especially C. namnetense, a new player in bone infections.

Catheter-related bloodstream infection due to Tsukamurella pulmonis identified by MALDI-TOF spectrometry, 16S rRNA gene sequencing, and secA1 gene sequencing in an immunocompromised child: a case report and literature review.

Tsukamurella species are Gram-positive bacilli related to aerobic Actinomyces. Originally reported from the environment, Tsukamurella species have also been described in human infections, especially in bacteremia. A literature review analysis revealed that Tsukamurella spp. are often initially considered as contaminant microorganisms, especially due to bacterial identification issues. Here, we report a catheter-related bloodstream infection in an immunocompromised child caused by Tsukamurella pulmonis. Matrix-Assisted Laser Desorption/Ionization-Time Of Flight (MALDI-TOF) mass spectrometry allowed rapid genus-level identification and contributed to better patient care. However, accurate species-level identification required 16S rRNA gene sequencing and secA1 gene sequencing. Considering the increased number of Tsukamurella infections, the implementation of new Tsukamurella species in MALDI-TOF databases is required to be more discriminant.

Propionibacterium/Cutibacterium species-related positive samples, identification, clinical and resistance features: a 10-year survey in a French hospital.

A 10-year retrospective study of Propionibacterium/Cutibacterium-positive samples gathered from hospitalized patients was conducted at Nantes University hospital. A total of 2728 Propionibacterium/Cutibacterium-positive samples analyzed between 2007 and 2016 were included. Due to the implementation of MALDI-TOF identification in 2013, most non-Cutibacterium acnes isolates were identified a second time using this technology. Over that period, Cutibacterium acnes remained the most predominant species accounting for 91.5% (2497/2728) of the isolates, followed by Cutibacterium avidum (4.2%, 115/2728) and Cutibacterium granulosum (2.4%, 64/2728). Regarding the origin of samples, the orthopaedic department was the main Cutibacterium sample provider representing 51.9% (1415/2728) of all samples followed by the dermatology department (11.5%, 315/2728). Samples were recovered from various tissue locations: 31.5% (858/2728) from surgery-related samples such as shoulder, spine or hip replacement devices and 19.1% (520/2728) from skin samples. MALDI-TOF method revealed misidentification before 2013. Cutibacterium avidum was falsely identified as C. granulosum (n = 33). Consequently, MALDI-TOF technology using up-to-date databases should be preferred to biochemical identification in order to avoid biased species identification. Regarding antibiotic resistance, 14.7% (20/136) of C. acnes was resistant to erythromycin. 4.1% (41/1005) of C. acnes strains, 17.9% (12/67) of C. avidum strains and 3.6% (1/28) of C. granulosum strains were found resistant to clindamycin.