Complete genome sequences of eight Auritidibacter ignavus strains isolated from ear infections in Germany.

Here, we present the complete genome sequences of eight Auritidibacter ignavus strains isolated from clinical samples of patients with ear infections in Bochum, Germany. The sequence information will give assistance to greater knowledge about the virulence potential of this unfamiliar putative pathogen.

MALDI-TOF mass spectrometry following short incubation on a solid medium is a valuable tool for rapid pathogen identification from positive blood cultures.

INTRODUCTION: Rapid identification of the causative microorganism is a key element in appropriate antimicrobial therapy of bloodstream infections. Whereas traditional analysis of positive blood cultures requires subculture over at least 16-24h prior to pathogen identification by, e.g. matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), sample preparation procedures enabling direct MALDI-TOF MS, i.e. without preceding subculture, are associated with additional effort and costs. Hence, we integrated an alternative MALDI-TOF MS approach in diagnostic routine using a short incubation on a solid medium. MATERIALS AND METHODS: Positive blood cultures were routinely plated on chocolate agar plates and incubated for 4h (37 °C, 5% CO2). Subsequently, MALDI-TOF MS using a Microflex LT instrument (Bruker Daltonics) and direct smear method was performed once per sample. For successful identification of bacteria at species level, score cut-off values were used as proposed by the manufacturer (≥ 2.0) and in a modified form (≥ 1.5 for MALDI-TOF MS results referring to Gram-positive cocci and ≥ 1.7 for MALDI-TOF MS results referring to bacteria other than Gram-positive cocci). Further data analysis also included an assessment of the clinical impact of the MALDI-TOF MS result. RESULTS: Applying the modified score cut-off values, our approach led to an overall correct species identification in 69.5% with misidentification in 3.4% (original cut-offs: 49.2% and 1.8%, respectively); for Gram-positive cocci, correct identification in 68.4% (100% for Staphylococcus aureus and enterococci, 80% for beta-hemolytic streptococci), for Gram-negative bacteria, correct identification in 97.6%. In polymicrobial blood cultures, in 72.7% one of the pathogens was correctly identified. Results were not reliable for Gram-positive rods and yeasts. The approach was easy to implement in diagnostic routine. In cases with available clinical data and successful pathogen identification, in 51.1% our approach allowed an optimized treatment recommendation. CONCLUSION: MALDI-TOF MS following 4h pre-culture is a valuable tool for rapid pathogen identification from positive blood cultures, allowing easy integration in diagnostic routine and the opportunity of considerably earlier treatment adaptation.

Description of IMP-31, a novel metallo-ß-lactamase found in an ST235 Pseudomonas aeruginosa strain in Western Germany.

OBJECTIVES: The objective of this study was to characterize a novel IMP-type metallo-ß-lactamase (MBL) found in an MDR clinical isolate of Pseudomonas aeruginosa. METHODS: The P. aeruginosa isolate NRZ-00156 was recovered from an inguinal swab from a patient hospitalized in Western Germany and showed high MICs of carbapenems. MBL production was analysed by Etest for MBLs, an EDTA combined disc test and an EDTA bioassay. Typing of the isolate was performed by MLST. Genetic characterization of the new blaIMP gene was performed by sequencing the PCR products. A phylogenetic tree was constructed. The novel blaIMP gene was expressed in Escherichia coli TOP10 and the enzyme was subjected to biochemical characterization. RESULTS: The P. aeruginosa isolate NRZ-00156 expressed the ST235 allelic profile and was resistant to all the ß-lactams tested except aztreonam. The isolate was positive for MBL production and harboured a new IMP allele, blaIMP-31, located on a disrupted class I integron [also carrying the blaOXA-35, aac(6')-Ib, aac(3)-Ic and aphA15 genes]. Its closest relative was IMP-35, with 96.7% amino acid identity. Expression of blaIMP-31 demonstrated that E. coli TOP10 producing IMP-31 had elevated resistance to all the ß-lactams tested except aztreonam. Kinetic data were obtained for both IMP-31 and IMP-1. In comparison with IMP-1, IMP-31 showed weaker hydrolytic activity against all the ß-lactams tested, which resulted from lower kcat values. CONCLUSIONS: The characterization of the new IMP-type gene blaIMP-31 from an ST235 P. aeruginosa isolate indicates an ongoing spread of highly divergent IMP-type carbapenemases in clinical P. aeruginosa strains and highlights the continuous need for the prevention of nosocomial infections caused by MDR Gram-negative bacteria.

Hare-to-human transmission of Francisella tularensis subsp. holarctica, Germany.

In November 2012, a group of 7 persons who participated in a hare hunt in North Rhine-Westphalia, Germany, acquired tularemia. Two F. tularensis subsp. holarctica isolates were cultivated from human and hare biopsy material. Both isolates belonged to the FTN002-00 genetic subclade (derived for single nucleotide polymorphisms B.10 and B.18), thus indicating likely hare-to-human transmission.

Description of the metallo-ß-lactamase GIM-1 in Acinetobacter pittii.

OBJECTIVES: To characterize the mechanisms involved in the reduced carbapenem susceptibility of five Acinetobacter pittii strains isolated from different regions of Germany. METHODS: The strains were analysed by susceptibility testing, phenotypic tests for metallo-ß-lactamase production, sequencing of the integron structure and strain typing by PFGE, as well as multilocus sequence typing (MLST) and plasmid analysis by S1 restriction and hybridization. RESULTS: Despite GIM-1 production, the MICs of imipenem were only 4 mg/L for four strains and some methods of phenotypic MBL detection failed. According to PFGE and MLST, the strains belonged to four different clones, but blaGIM-1 was present in identical integron structures in all strains and carried on plasmids of ∼60 kb. CONCLUSIONS: For the first time, GIM-1 has been demonstrated in A. pittii. This resistance mechanism has previously been reported only in Enterobacteriaceae and Pseudomonas aeruginosa. As GIM-1 was found in strains with diverse clonal backgrounds, but encoded on plasmids of a similar size, further spread among Acinetobacter spp. seems possible. The detection of GIM-1 production might be challenging in some strains due to the low MICs of carbapenems.

MRSA in dermatology - Prospective epidemiological study in employees and patients of a dermatological department of a university hospital.

BACKGROUND: In recent years, the prevalence of MRSA has increased worldwide. There is a lack of systematic epidemiological studies evaluating the prevalence of MRSA in dermatology in Germany. OBJECTIVE: What is the prevalence of MRSA in the employees and hospitalized patients in a dermatological department? What dermatological diagnoses have the highest risk for MRSA? PATIENTS AND METHODS: Nasal swabs taken twice (at admission and discharge) from all consenting hospitalized patients and once from all consenting employees were analyzed for MRSA. RESULTS: Analysis von 798 swabs (715 patients, 83 employees). Detection of MRSA in 31 swabs (MRSA rates: all = 4.3 %, patients = 3.7 %, employees = 4.8 %). Patients with a chronic leg ulcer had a significantly increased risk for MRSA (p = 0.03). Increased MRSA rates without statistical significance were found for men, patients with at least one hospitalization during the last 12 weeks and a hospitalization of at least 5 days. None of the patients with psoriasis had MRSA. CONCLUSIONS: In comparison to international studies, the prevalence of MRSA in the current study is in the lower third. In dermatology, patients with a chronic leg ulcer have an increased risk for MRSA and should be screened at admission. A general screening for MRSA seems to be not reasonable in view of the low MRSA rates in the investigated department.

Screening of platelet concentrates for bacterial contamination: spectrum of bacteria detected, proportion of transfused units, and clinical follow-up.

Screening of platelet concentrates (PCs) for bacterial contamination with cultivation methods is carried out as a routine procedure in some countries. The aim is to prevent the transfusion of contaminated PCs. The German Evaluation of Regular Monitoring Study Group conducted a prospective multicenter study on 52,243 PCs to investigate the prevalence of bacteria (BacT/ALERT, bioMerieux). This study describes the detected bacterial spectrum, the proportion of PCs with a positive test result that had been transfused, and the results of the clinical follow-up. One hundred thirteen (67%) of 169 potentially or confirmed positive units had already been transfused at the time of the first positive signal. The transfusion of units contaminated by Staphylococcus aureus, Serratia marcescens, and 73% of the units contaminated with Staphylococcus epidermidis, Staphylococcus capitis, or Staphylococcus saccharolyticus was prevented. In contrast, 85% of units with Propionibacterium acnes were transfused. A clonal relationship of the isolates from the pooled PCs and from the associated red blood cell concentrates was found in all investigated cases. The follow-up revealed six febrile reactions to culture-positive PCs not classified as transfusion reaction (TRs) by treating physicians. This demonstrates the importance of hemovigilance. Serious septic reactions due to Klebsiella pneumoniae in two units of one apheresis PC that had tested false-negative were reported; one had a fatal outcome. Culture systems reduce the risk of transfusion of contaminated PCs but cannot guarantee sterility. Physicians must be aware of bacterial contamination of PCs as a potential cause of TRs and must report all adverse events.

Bacterial contamination of platelet concentrates: results of a prospective multicenter study comparing pooled whole blood-derived platelets and apheresis platelets.

BACKGROUND: The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy-coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system. STUDY DESIGN AND METHODS: In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux). RESULTS: In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed-positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed-positive units. With a "negative-to-date" issue strategy, most PC units (55%) had already been issued by time of the first positive culture. CONCLUSION: The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false-negative results.