Objectives: Multiplex PCR assays offer highly sensitive and specific tools for the detection of enteric pathogens. This prospective study aimed at comparing the novel Roche LightMix Modular Assay Gastro Parasites (LMAGP) detecting Giardia duodenalis, Entamoeba histolytica, Cryptosporidium spp., Blastocystis hominis, and Dientamoeba fragilis with routine laboratory procedures. Methods: Stool specimens (n ¼ 1062 from 1009 patients) were consecutively examined by LMAGP, R-Biopharm Ridascreen enzyme immunoassays (EIAs) detecting G. duodenalis or E. histolytica/dispar, and microscopy of wet mounts. Discrepant results were analysed by in-house PCR. Results: D. fragilis or B. hominis were detected by LMAGP in 131 (14.4%) and 179 (19.9%; 16 samples positive by microscopy; p < 0.0001) of 909 samples, respectively. Of 918 samples analysed for Cryptosporidium spp., six were positive by LMAGP (three could be confirmed by Kinyoun staining and one by inhouse PCR). G. duodenalis was detected by LMAGP, EIA, or microscopy in 20, 16, or 9 of 1039 stool samples, respectively; all four samples missed by EIA were confirmed by in-house PCR. In total, 938 stool samples were analysed for E. histolytica/dispar. Nine of ten EIA-positive samples were negative by LMAGP but positive by in-house PCR for E. dispar. One E. histolytica infection (positive by both LMAGP and inhouse PCR) was missed by EIA and microscopy. Parasites only detected by microscopy included Enterobius vermicularis eggs (n ¼ 3) and apathogenic amoebae (n ¼ 27). Conclusions: The data call for routine use of multiplex PCR assays for the detection of enteric protozoan parasites in laboratory diagnostics.

Objectives: To characterize deep skin and soft tissue infections (dSSTI) caused by Panton-Valentine leukocidin (PVL)-positive versus PVL-negative Staphylococcus aureus isolates. Methods: We 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 2007e2017. Bacterial isolates were identified and tested for antimicrobial susceptibility by VITEK 2; PVL was detected by PCR. Results: In total, 1199 S. aureus isolates from 1074 patients with dSSTI were identified, and 613 (51.1%) of 1199 samples were PVL þ . The median age of patients with PVL þ S. aureus was lower than in patients with PVLÀ S. aureus (34 years, range 0e88 years, vs. 44 years, range 0e98 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), 2.2e5.8). Interestingly, the highest PVL positivity rate was found in isolates from gluteal (82/108, 75.9%; OR, 3.6; 95% CI, 2e5) or axillary (76/123, 61.8%; OR, 2; 95% CI, 1.1e3.3) 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 þ isolates, mainly methicillin-sensitive S. aureus, when considering SXT resistance rates of 2007e2012 versus 2013e2017 (35/226, 15.5% vs. 74/289, 25.6%; p 0.01). Conclusions: In outpatients, gluteal and axillary dSSTI are indicative of PVL þ S. aureus. Providing SXT as a complementary treatment for dSSTI should be based on susceptibility testing.

This study aimed at evaluating in outpatients an algorithm for the laboratory diagnosis of Clostridioides (Clostridium) difficile infection (CDI), i.e., enzyme immunoassays (EIAs) detecting bacterial glutamate dehydrogenase (GDH) and toxin A/B, followed by polymerase chain reaction (PCR) analyses of samples with discordant EIA results.In total, 9802 examinations of stool samples by GDH and toxin EIAs performed in 7263 outpatients and 488 inpatients were analyzed retrospectively. Samples with discordant EIA results had been tested by a commercially available PCR assay detecting genes of the C. difficile-specific triose phosphate isomerase (tpi) and toxin B (tcdB). Concordant EIA results (686 C. difficile-positive, 8121 negative) were observed for 8807 (89.8%; 95% CI, 89.2–90.4%) samples. Of 958 samples with discordant EIA results, 895 were analyzed using PCR and 580 of 854 GDH-positive/borderline, toxin-negative samples (67.9%; 95% CI, 64.7–71.0%) were positive for tpi and tcdB, while 274 samples (32.1%; 95% CI, 29.0–35.3%) were tcdB-negative. In contrast, 35 of 41 GDH-negative, toxin-positive/borderline samples (85.4%; 95% CI, 71.2–93.5%) were tcdB-negative. Still, 6 samples (14.6%; 95% CI, 6.5–28.8%) yielded positive PCR results for both genes.In conclusion, around 90% of the samples were analyzed appropriately by only applying EIAs. Approximately one third of the PCR-analyzed samples were tcdB-negative; thus, patients most likely did not require CDI treatment.

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