Panton-Valentine leukocidin–positive Staphylococcus aureus in skin and soft tissue infections from primary care patients

ObjectivesTo characterize deep skin and soft tissue infections (dSSTI) caused by Panton-Valentine leukocidin (PVL)-positive versus PVL-negative Staphylococcus aureus isolates.MethodsWe performed a retrospective analysis of patients' records including S. aureus isolates from outpatients with dSSTI. Samples had been submitted by primary care physicians, i.e. general practitioners, surgeons, dermatologists and paediatricians, located in Berlin, Germany, in 2007–2017. Bacterial isolates were identified and tested for antimicrobial susceptibility by VITEK 2; PVL was detected by PCR.ResultsIn total, 1199 S. aureus isolates from 1074 patients with dSSTI were identified, and 613 (51.1%) of 1199 samples were PVL⁺. The median age of patients with PVL⁺ S. aureus was lower than in patients with PVL− S. aureus (34 years, range 0–88 years, vs. 44 years, range 0–98 years; p < 0.0001). PVL was associated with repeated/multiple samples compared to single sample submission (69/92, 75% vs. 448/982, 45.6%, p < 0.0001; odds ratio (OR), 3.6; 95% confidence interval (CI), 2.2–5.8). Interestingly, the highest PVL positivity rate was found in isolates from gluteal (82/108, 75.9%; OR, 3.6; 95% CI, 2–5) or axillary (76/123, 61.8%; OR, 2; 95% CI, 1.1–3.3) localizations compared to isolates from the arm. The PVL positivity rate did not increase over time. Yet we noticed an increase in the trimethoprim/sulfamethoxazole (SXT) resistance rate in PVL⁺ isolates, mainly methicillin-sensitive S. aureus, when considering SXT resistance rates of 2007–2012 versus 2013–2017 (35/226, 15.5% vs. 74/289, 25.6%; p 0.01).ConclusionsIn outpatients, gluteal and axillary dSSTI are indicative of PVL⁺ S. aureus. Providing SXT as a complementary treatment for dSSTI should be based on susceptibility testing.     

Prevalence of community-associated meticillin-resistant Staphylococcus aureus and Panton–Valentine leucocidin-positive S. aureus in general practice patients with skin and soft tissue infections in the northern and southern regions of The Netherlands

The purpose of this investigation was to determine the prevalence of community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) and Panton–Valentine leucocidin (PVL)-positive S. aureus in general practice (GP) patients with skin and soft tissue infections (SSTI) in the northern (Groningen and Drenthe) and southern (Limburg) regions of The Netherlands. Secondary objectives were to assess the possible risk factors for patients with SSTI caused by S. aureus and PVL-positive S. aureus using a questionnaire-based survey. From 2007 to 2008, wound and nose cultures were obtained from patients with SSTI in general practice. These swabs were analysed for the presence of S. aureus and the antibiotic susceptibility was determined. The presence of the PVL toxin gene was determined by polymerase chain reaction (PCR) and the genetic background with the use of spa typing. A survey was performed to detect risk factors for S. aureus infection and for the presence of PVL toxin.S. aureus was isolated from 219 out of 314 (70%) patients with SSTI, of which two (0.9%) patients were MRSA-positive. In 25 (11%) patients, the PVL toxin gene was found. A higher prevalence of PVL-positive S. aureus of patients with SSTI was found in the northern region compared to the south (p < 0.05). Regional differences were found in the spa types of PVL-positive S. aureus isolates, and for PVL-negative S. aureus isolates, the genetic background was similar in both regions. The prevalence of CA-MRSA in GP patients with SSTI in The Netherlands is low. Regional differences were found in the prevalence of PVL-positive S. aureus isolates from GP patients with SSTI. Household contacts having similar symptoms were found to be a risk factor for SSTI with S. aureus.     

Are guidelines on the management of non-tuberculous mycobacteria lung infections respected and what are the consequences for patients? A French retrospective study from 2007 to 2014

Diagnosis and treatment of lung infections caused by non-tuberculous mycobacteria (NTM) remain challenging. Adherence of the clinicians to the American Thoracic Society (ATS) and the Infectious Diseases Society of America (IDSA) 2007 guidelines is often incomplete. Between 2007 and 2014, in Grenoble Alpes University Hospital, France, 132 patients had NTM-positive cultures from lower respiratory tract (LRT) samples. We retrospectively collected diagnosis, treatment, and outcome data of patients, and evaluated the adherence of clinicians to ATS/IDSA guidelines and the consequences of patients’ prognoses. Using the ATS/IDSA definitions, 31 out of 132 patients (23.5%) were considered infected, 57 out of 132 patients (43.2%) were considered colonised, 33 out of 132 (25%) were contaminated and 11 (8.4%) had missing data. Among the 31 NTM-infected patients, M. avium (23 out of 31, 74.2%) was most frequently involved. The main risk factor for NTM lung infection was underlying lung disease (30 out of 31, 96.8%). Treatment was not appropriate according to current guidelines in 58.1% of infected patients (18 out of 31). Mainly, the antibiotic treatment was installed based on radiological signs (p = 0.0006), sputum results and bronchoalveolar lavage results (p < 0.0001 and p = 0.003 respectively). Most antibiotic regimens included a macrolide (83.4%). Patients receiving appropriate treatment had the same cure rates as those receiving inappropriate treatment (p = 0.22) and similar relapse rates (p = 0.92). Current medical practices for the treatment of NTM lung infections in our institution are not consistent with the ATS/IDSA guidelines. This could potentially affect the prognosis of these patients and favour the emergence of macrolide resistance in NTM species.