Turicella otitidis and Corynebacterium auris: 20 years on.

Turicella otitidis and Corynebacterium auris, described as new species 20 years ago, have been isolated mainly from the external ear canal and middle ear fluid. While their taxonomic position has been clearly established, their diagnosis in the routine laboratory is difficult. The question of their pathogenic potential in otitis is still open but might be elucidated better if corynebacteria are speciated more often.

Identification of coryneform and other gram-positive rods with several methods.

The identification of 202 isolates of aerobically growing Gram-positive rods from clinical material was attempted by using a combination of "traditional" morphological and biochemical tests (Hollis & Weaver (20)) plus patterns of cellular and metabolic fatty acids. This system served as the "gold standard" for three others, i.e. API Coryne (Rapid Coryne), MIDI TSBA and MIDI CLIN Aerobic. In addition, several growth, biochemical and susceptibility tests (growth on cystine-tellurite blood agar, DNase, hippurate and starch hydrolysis, methanethiol formation, API ZYM, CAMP reaction, susceptibility to O/129 and to six antimicrobials) were done in order to check their usefulness for the identification of this group of bacteria. Our system, with the help of chemotaxonomic tests (m-DAP and mycolic acids), was able to identify 154/202 (76%) of the isolates by species and an additional 41/202 (21%) by genus only; 7 (3%) could not be identified. The API Coryne system identified to species or genus level 140/195 isolates (72%). Corresponding figures for the MIDI TSBA and CLIN systems were 63/195 (32%) and 88/195 (45%); further details of species and genus identification are presented in the text. The main drawback of the commercial systems is the extent and probably the numerical depth of the data base. We recommend the use of our multisystem approach for the identification of Gram-positive rods until commercial systems are based on a broader and numerically more extensive data base. The additional tests did not prove species- or genus-specific.

Heterogeneity within Corynebacterium minutissimum strains is explained by misidentified Corynebacterium amycolatum strains.

Forty-eight clinical strains that were tentatively identified as Corynebacterium minutissimum on the basis of standard biochemical reactions (Hollis-Weaver tables) as well as by the use of the API (RAPID) Coryne system were examined further. Two different groups of strains were observed. The first group (including the type strain of C minutissimum) contained 27 strains showing creamy colonies. These strains grew homogeneously in 6.5% NaCl broth, exhibited DNase activity, were susceptible to the vibriocidal compound O/129, produced succinic acid, and contained mycolic acids. The second group comprised 21 strains with dry colonies. They grew in clumps at the surface of 6.5% NaCl broth, DNase activity was not detected, they were resistant against O/129, produced large amounts of propionic acid, and mycolic acids were not detected. In combination with quantitative DNA-DNA hybridizations, it was demonstrated that strains of the second cluster belonged, in fact, to C amycolatum. Furthermore, it was observed that a few C minutissimum strains may also ferment mannitol. These data indicate that the clinical microbiologist must be careful not to misidentify C amycolatum strains as C minutissimum.

Rahnella aquatilis bacteremia in an HIV-infected intravenous drug abuser.

Rahnella aquatilis, an unusual enteric Gram-negative rod, was isolated from three of four blood cultures of an HIV-infected intravenous drug abuser. The outcome was favorable after a 14-day course with ciprofloxacin. The identification of R. aquatilis isolates is discussed and a synopsis of the previously published antimicrobial susceptibility patterns of this microorganism is given.

Corynebacterium lipophiloflavum sp. nov. isolated from a patient with bacterial vaginosis.

A unique coryneform bacterium was isolated from a patient with bacterial vaginosis. Chemotaxonomical investigations demonstrated that the unknown bacterium belonged to the genus Corynebacterium. The yellow-pigmented, slightly lipophilic, oxidative, urea-hydrolyzing bacterium could be phenotypically readily differentiated from the other members of the genus Corynebacterium. Comparative 16S rRNA gene analysis revealed that the bacterium represented a new subline within the genus Corynebacterium for which the name Corynebacterium lipophiloflavum sp. nov. is proposed. The type strain is CCUG 37336 (DSM 44291).

Aureobacterium resistens sp. nov., exhibiting vancomycin resistance and teicoplanin susceptibility.

Two similar strains of a coryneform bacterium were isolated from human clinical material. Both strains were resistant to vancomycin but susceptible to teicoplanin. Detailed biochemical, chemotaxonomical, and molecular genetic investigations revealed that both isolates were members of a hitherto undescribed species of genus Aureobacterium. The name Aureobacterium resistens sp. nov. is proposed for the new bacterium and the type strain is CCUG 38312.

Natural antibiotic susceptibility of Listeria species: L. grayi, L. innocua, L. ivanovii, L. monocytogenes, L. seeligeri and L. welshimeri strains.

OBJECTIVE: To investigate the natural susceptibility to 71 antimicrobial agents of 103 Listeria strains belonging to all known Listeria species (L. monocytogenes (N = 21), L. innocua (N = 21), L. seeligeri (N = 21), L. ivanovii (N = 19), L. welshimeri (N = 11), and L. grayi (N = 10)). METHODS: MICs were determined using a microdilution procedure in H-Medium. RESULTS: All listeriae were naturally sensitive or intermediate to tetracyclines, aminoglycosides, penicillins (except oxacillin), loracarbef, cefazoline, cefaclor, cefotiam, cefoperazone, carbapenems, macrolides, lincosamides, glycopeptides, dalfopristin/quinupristin, chloramphenicol and rifampicin (probably except L. grayi). Listeria spp. were naturally resistant or intermediate to most 'modern' cephalosporins (cefetamet, cefixime, ceftibuten, ceftazidime, cefdinir, cefpodoxime, cefotaxime, ceftriaxone, cefuroxime), aztreonam, pipemidic acid, dalfopristin quinupristin and sulfamethoxazole. Significant differences in natural susceptibility among the species were seen with the quinolones, trimethoprim, co-trimoxazole, rifampicin, fosfomycin and fusidic acid. It seems likely that L. grayi is naturally resistant to all antifolates; the species was least susceptible to rifampicin and most susceptible to quinolones, whereas L. ivanovii was naturally resistant to most quinolones. L. ivanovii was naturally sensitive to fosfomycin, whereas L. innocua and L. monocytogenes were naturally resistant. L. ivanovii was also the most susceptible species to fusidic acid. CONCLUSIONS: The present study describes a database on the natural susceptibility of Listeria spp. to a wide range of antibiotics, which can be used to validate susceptibility testing results of these microorganisms.

Corynebacterium macginleyi: a conjunctiva specific pathogen.

BACKGROUND: Although non-diphtherial corynebacteria are ubiquitous in nature and commonly colonise the skin and mucous membranes of humans, they rarely account for clinical infection. METHODS AND RESULTS: 10 patients with unilateral conjunctivitis are described in which Corynebacterium macginleyi was isolated. This species has only recently been reported to be exclusively isolated form ocular surfaces. C macginleyi was uniformly susceptible to topical antibiotics commonly used in ophthalmology. CONCLUSION: Despite the fact that the pathogenicity of C macginleyi is not yet assured, this micro-organism should be recognised as a potential cause of bacterial superinfections. Appropriate antibiotic therapy leads to its elimination and resolution of the conjunctivitis.

[Interference factors in the in vivo diagnosis of the thyroid]. / Störfaktoren bei der In-vivo-Diagnostik der Schilddrüse.

Anamnestic iodine contamination and medication with thyroid drugs were registered in 260 patients of a clinical thyroid care unit and 200 patients of a thyroid doctor's office in the southern German endemic goiter region. We found in the university clinic 54% patients with interfering factors, 30% with iodine contamination and 20% with multiple interferences. In the physician's practice there were 18%, nearly all treated with thyroid hormone. The influence of those factors on thyroidal technetium uptake and the resulting restriction on its diagnostic value is discussed.

[Quality-agreement colonoscopy: an outcome evaluation from the district of North-Württemberg, Germany, 2003 - 2007]. / Qualitätssicherungsvereinbarung Koloskopie: Eine Ergebnisevaluierung aus Nord-Württemberg 2003 - 2007.

Diverse problems with the hygienically correct reprocessing of endoscopes and resulting transmissions of pathogens over the last decades are well documented. As a consequence, the worldwide first evidence-based compulsory guidelines for all endoscopy units in clinics and practices were implemented in Germany in 2002. The presented study reports for the first time ever on a detailed outcome evaluation of these guidelines. Data of all routine and all required 1st and 2nd re-examinations of endoscopes from all units (clinics and practices) performing endoscopy in the district of Nord-Württemberg, Germany, between 2003 and 2007 were analysed. A significant (p < 0.0001) overall decrease of insufficiently sterilised endoscopes was found during the observation period. The proportion of required re-examinations in clinics was below 10 % already in 2003 and remained within single figure percentages over the following years. In doctors' practices, however, in 2003 nearly every second routine examination of endoscopes required a re-examination and a significant (p < 0.0001) decrease of these figures was only found from 2004 onwards. A significant trend (p < 0.01) of re-processing techniques away from manual techniques towards fully automated procedures could be documented. No significant changes with respect to the localisation or the spectrum of the detected pathogens during control examinations were found. The presented outcome evaluation demonstrates that the implementation of stringent compulsory guidelines in Germany (and the conditional refund from the public health system for screening procedures linked to them) resulted in a substantial and significant improvement of hygiene in the re-processing of flexible endoscopes.

Vehicle automation: a remedy for driver stress?

The present study addressed the effects of stress, vehicle automation and subjective state on driver performance and mood in a simulated driving task. A total of 168 college students participated. Participants in the stress-induction condition completed a 'winter' drive, which included periodic loss of control episodes. Participants in the no-stress-induction condition were not exposed to loss of control. An additional, independent manipulation of vehicle speed was also conducted, consisting of two control conditions requiring manual speed regulation and a third in which vehicle speed was automatically regulated by the simulation. Stress and automation both influenced subjective distress, but the two factors did not interact. Driver performance data indicated that vehicle automation impacted performance similarly in the stress and no-stress conditions. Individual differences in subjective stress response and performance were also investigated. Resource theory provides a framework that partially but not completely explains the relationship between vehicle automation and driver stress. Implications for driver workload, safety and training are discussed.

Minimal inhibitory concentrations of linezolid against clinical isolates of coryneform bacteria.

In order to evaluate the efficacy of linezolid for treating severe infections with coryneform bacteria, the activity of linezolid was tested in vitro against 425 clinically relevant isolates of coryneform bacteria and compared with the activity of penicillin and erythromycin. The minimal inhibitory concentration of linezolid did not exceed 2 microg/ml for any of the isolates tested, indicating that this agent has very good activity against coryneform bacteria. These results suggest linezolid is a possible alternative antimicrobial agent for the treatment of severe infections caused by coryneform bacteria.

Differentiation of Brevibacterium spp. encountered in clinical specimens.

Forty-three strains belonging to the genus Brevibacterium which were encountered in clinical materials over 2 decades were compared with reference strains, including the type strains, of B. casei, B. epidermidis, B. mcbrellneri, B. iodinum, and B. linens. By means of carbohydrate assimilation tests (CATs) the 43 clinical isolates could be assigned to the species B. casei (n = 41) and B. epidermidis (n = 2). DNA-DNA hybridizations were performed for 20 clinical isolates and confirmed the species identification of the isolates. Cellular fatty acid profiles of all strains were determined and found to have less discriminative power than CATs. This is the first report indicating that most clinical Brevibacterium isolates are B. casei and that CATs provide an easy-to-perform method for species determination within the genus, thus avoiding nucleic acid techniques.

Isolation of Escherichia fergusonii from four different sites in a patient with pancreatic carcinoma and cholangiosepsis.

Escherichia fergusonii was isolated from a 69-year-old male with pancreatic carcinoma and cholangiosepsis from gallbladder fluid, three blood cultures, feces, and a superficial wound of the abdomen. Biochemical reactions, antimicrobial susceptibility patterns, susceptibility to polyvalent phage 0-1, and rRNA gene restriction analysis suggested that the four strains were of clonal origin. Our data indicate that E. fergusonii possesses a pathogenic potential in humans.

Pitfalls in the diagnosis of intussusception.

Unusual sonographic behavior of intussusception is demonstrated in 4 cases. The results of 54 well-documented cases have shown two possible deviations from the normal sonographic pattern of an intussusception. The first was a highly reflective target sign, and the second a loss of regular sonographic structure in a tumor-like mass.

An identification scheme for rapidly and aerobically growing gram-positive rods.

An identification scheme for aerobically growing Gram-positive rods (genera Actinomyces, Arcanobacterium, Aureobacterium, Bacillus, Brevibacterium, Cellulomonas, Corynebacterium, Dermabacter, Erysipelothrix, Gardnerella, Lactobacillus, Listeria, Microbacterium, Oerskovia, Propionibacterium, Rhodococcus, Rothia, Turicella, as well as unnamed CDC groups, Clostridium tertium, and Mycobacterium fortuitum/chelonae) is presented. It is derived from the Hollis-Weaver scheme and uses catalase, oxidative/fermentative carbohydrate metabolism and motility as primary reactions. Tests for lipophilism, nitrate reduction, urease, esculin hydrolysis, the CAMP reaction, acid formation from five carbohydrates, as well as for some facultative reactions should lead to a correct diagnosis based on information available at the end of 1995.

Infections due to Actinomyces neuii (former "CDC coryneform group 1" bacteria).

Sixty-seven patients with infections in which the recently proposed species Actinomyces neuii was involved were observed during a 4 1/2-year period. Microbiological as well as clinical features of the patients are presented. A. neuii does not cause typical actinomycosis and is detected most often in material from abscesses or infected atheromas. One case of a fatal septicemia caused by A. neuii in a non-immunocompromised host was seen. Antimicrobial susceptibility patterns of A. neuii isolates and results of various treatment regimens are discussed.

Primary identification of Microbacterium spp. encountered in clinical specimens as CDC coryneform group A-4 and A-5 bacteria.

Over nearly two decades, 13 yellow- or orange-pigmented, fermentative gram-positive rods belonging to the genus Microbacterium were encountered in clinical specimens. All 13 strains, 10 of which came from blood cultures, were initially identified as CDC coryneform group A-4 and A-5 bacteria according to the scheme of Hollis and Weaver for the identification of gram-positive rods. The clinical isolates were compared with the type strains of the six species constituting the genus Microbacterium as well as with three Microbacterium strains isolated from hospital environments. By biochemical methods only 5 of 13 clinical isolates could be identified to species level. Peptidoglycan analysis proved to be a valuable tool for differentiation between Microbacterium spp. and related genera, whereas cellular fatty acid analysis did not allow species identification within the genus Microbacterium. The 22 Microbacterium strains studied were, in general, susceptible to antimicrobial agents used in the treatment of infections caused by gram-positive rods. This report is the first one concerning the isolation of Microbacterium strains from clinical specimens. The sources as well as the mode of transmission remain to be established.

rRNA gene RFLP as an identification tool for Corynebacterium species.

The value of rRNA gene RFLP analysis (ribotyping) as a tool for Corynebacterium and Turicella species identification was evaluated. Seventy-four strains representing 26 different species or subspecies were analysed by BstEII, SmaI and SphI ribotyping. Numerical analysis of the resulting rDNA banding patterns was performed by Dice coefficient correlation in order to establish a database for species identification. In general, most of the strains belonging to the same species clustered together. Interestingly, BstEII clustering of many species followed known phylogenetic lineages. This was not evident with the more heterogeneous SmaI and SphI patterns. The SmaI patterns contained a 1800 bp band in the digests of all species studied with the exception of Corynebacterium urealyticum. SphI digestion resulted in the most heterogeneous patterns. The information provided by all three enzymes was considered essential for the reliable linking of strains of unknown identity with defined species in the database. It is concluded that ribotyping provides an useful tool for screening and characterization of potentially new Corynebacterium species.