Dietzia cinnamea sp. nov., a novel species isolated from a perianal swab of a patient with a bone marrow transplant

The taxonomic status of a bacterium isolated from a perianal swab of a patient with a bone marrow transplant was characterized using a polyphasic taxonomic approach. Chemotaxonomic investigations revealed the presence of cell wall chemotype IV, short chain mycolic acids that co-migrated with those extracted from members of the genus Dietzia, and a dihydrogenated menaquinone with eight isoprene units as the predominant menaquinone. Generic assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that this isolate constitutes a distinct phyletic line within the genus Dietzia, displaying 97·5–98·7 % sequence similarity with Dietzia species with validly published names. The isolate could be distinguished from the type strain of Dietzia maris (1·6 % sequence divergence) and other species of the genus Dietzia by DNA–DNA hybridization, as well as by using a set of biochemical tests. Genotypic and phenotypic data show that the strain merits classification as a novel species of the genus Dietzia for which the name Dietzia cinnamea sp. nov. is proposed; the type strain is IMMIB RIV-399T (=DSM 44904T=CCUG 50875T).

Reclassification of Nocardia corynebacterioides Serrano et al. 1972 (Approved Lists 1980) as Rhodococcus corynebacterioides comb. nov

The type strain of Nocardia corynebacterioides was the subject of a polyphasic taxonomic study. The 16S rRNA gene sequence was aligned with the sequences of representatives of the genera Corynebacterium, Dietzia, Gordonia, Mycobacterium, Nocardia, Rhodococcus, Skermania, Tsukamurella and Williamsia, and phylogenetic trees were constructed by using maximum-parsimony, maximum-likelihood and neighbour-joining methods. It was evident from the phylogenetic analysis that N. corynebacterioides represents a distinct phyletic line within the genus Rhodococcus. Menaquinone analysis showed that the organism contained dihydrogenated menaquinone with eight isoprene units, MK-8(H2), as the major isoprenologue. The genealogical evidence, together with chemotaxonomic and phenotypic data from this and previous studies, indicates that N. corynebacterioides DSM 20151T (=CIP 104510T) should be reclassified in the genus Rhodococcus as Rhodococcus corynebacterioides comb. nov.

Isolation of Fungi, Especially Exophiala dermatitidis, in Patients Suffering from Cystic Fibrosis

BACKGROUND

Patients with cystic fibrosis (CF) are at an increased risk of pulmonary colonisation by opportunistic micro-organisms. Using specialised methods, the black yeast Exophiala dermatitidis could consistently be cultured from CF patients. Isolation rates from sputum samples ranged between 1.8 and 15.7%. Occasionally, infection could be recognised.

OBJECTIVES

This study aimed at investigating the isolation rates of E. dermatitidis in samples taken from CF patients at the University of Bonn, Germany.

METHODS

Altogether, 439 respiratory specimens taken from 81 CF patients were screened for the occurrence of E. dermatitidis over a period of 18 months. For the selective isolation of this fungus erythritol-chloramphenicol agar (ECA) produced in house was applied.

RESULTS

The isolation rate of E. dermatitidis was 1.1% from all specimens, 1.6% from all sputum samples and 6.2% in all patients examined.

CONCLUSIONS

Prior to the introduction of ECA, E. dermatitidis had never been isolated in our laboratory, either from CF, or from any other patient. During this study, E. dermatitidis was found to colonise the respiratory tract of some CF patients. The use of additional selective culture media is necessary for the recognition of uncommon fungi, e.g. E. dermatitidis, in CF patients.

Wound infection due toAbsidiacorymbiferaandCandida albicanswith fatal outcome

A case of a mixed infection due to Candida albicans and the zygomycete Absidia corymbifera in a 38-year-old, previously healthy, Caucasian male is presented. The infection developed following serial rib fractures, and ruptures of kidney, liver and biliary tract as well as a pancreatic contusion resulting from a traffic accident. During intensive care treatment the patient underwent several surgical procedures but subsequently experienced multi-organ failure and sepsis. Some weeks later, fungal growth was observed macroscopically on the patient's skin and wounds. From wound swabs C. albicans and A. corymbifera were grown. Histopathology of abdominal tissue yielded pseudohyphae and coenocytic hyphae. Although surgical debridement and antifungal treatment with amphotericin B and 5-flucytosine were started immediately, the patient died in therapy-refractory septic multi-organ failure.

Fatal pulmonary scedosporiosis. Letal verlaufende pulmonale Scedosporiose

We report on a case of scedosporiosis in a 72-year-old German woman. Her disease started with a purulent ulceration of unknown course at her left foot. Soon after onset of oral antibacterial therapy she needed in-hospital treatment because of an acute pneumonia. The infection progressed despite the application of different antibiotics. Microscopic examination of tracheal fluid revealed fungal hyphae and therefore treatment with itraconazole was initiated. However, the patient developed renal failure, required mechanical ventilation and finally died in treatment-resistant septic shock. Post-mortem Scedosporium apiospermum was cultured from lung tissue taken during autopsy. This is the fourth case of human infection caused by Scedosporium species diagnosed in our laboratory during the last 4 years.

Nocardia puris sp. nov

A bacterial isolate (IMMIB R-145(T)) from a human abscess was subjected to a polyphasic taxonomic study. Chemotaxonomic investigations revealed the isolate to have cell wall chemotype IV and mycolic acids consistent with characteristics of the genus NOCARDIA: Comparative 16S rRNA gene sequencing showed that the isolate constituted a distinct subline within the genus Nocardia, displaying greater than 1.7 % sequence divergence with established species. However, a DNA-DNA hybridization study demonstrated unambiguously that the isolate was genealogically distinct from closely related species, namely, Nocardia abscessus, Nocardia cyriacigeorgica and Nocardia farcinica, with which it showed high levels of 16S rDNA sequence similarity (97.8, 97.9 and 98.3 %, respectively). Based on phenotypic and phylogenetic data, it is proposed that this isolate be classified as a new species of the genus Nocardia, for which the name Nocardia puris (type strain IMMIB R-145(T)=DSM 44599(T)=NRRL B-24204(T)) is proposed.

Human cervicofacial actinomycoses: microbiological data for 1997 cases

Actinomycoses are sporadically occurring endogenous polymicrobial inflammatory processes, in which fermentative actinomycetes of the genera Actinomyces, Propionibacterium, or Bifidobacterium act as the principal pathogens. Difficulties in diagnosing the disease in a timely and reliable fashion have led clinicians and microbiologists to grossly underestimate its medical importance. Therefore, we evaluated microbiological and selected clinical data derived from 1997 culture-positive cases of human cervicofacial actinomycoses examined in our laboratories during 1972-1999. The causative actinomycetes belonged to at least 9 different species, among which Actinomyces israelii and Actinomyces gerencseriae predominated. The well-known predisposition of male patients to acquire the disease varied with age and appeared to be especially pronounced in patients aged 20-60 years, the highest incidence being found in female patients aged 11-40 years and in male patients aged 21-50 years. The relevant procedures necessary for diagnosing human actinomycoses reliably, as well as details of their complex etiology, are discussed.

Case Report. Maxillary sinus infection due to Emericella nidulans

Fungal infections of the maxillary sinus are frequently caused by Aspergillus species, particularly A. fumigatus. In otherwise healthy persons there is an association with overfilling of dental root canals, when zinc-containing filling materials were used. Below, a maxillary sinus aspergilloma is reported in a young immunocompetent female patient caused by Aspergillus (Emericella) nidulans.

Mycetoma due to Pseudallescheria boydii and co-isolation of Nocardia abscessus in a patient injured in road accident

We report the case of a patient who developed a mycetoma after experiencing a road accident. From surgical biopsies Pseudallescheria boydii was isolated. Subsequently, after the infection had been treated with itraconazole, a Gram-positive bacterium, identified as the newly described species Nocardia abscessus, was cultured from wound fluids.

Isolation of Nocardia paucivorans from the cerebrospinal fluid of a patient with relapse of cerebral nocardiosis

Nocardia paucivorans represents a new species of the genus Nocardia that has recently been isolated from bronchial secretions of a patient with chronic lung disease. Here, we report on the course of a disseminated infection caused by this species: i.e., cerebral and subsequent meningeal manifestations, isolation from the cerebrospinal fluid, and in vitro susceptibility to various antimicrobial agents.

A case of imported paracoccidioidomycosis in a German legionnaire

We report on a case of the chronic form of paracoccidioidomycosis with swelling and ulcerations of the mouth in a German legionnaire who also suffered from a chronic bronchitis. The patient had worked for many years in Brazil, an area endemic for the disease. Infection due to Paracoccidioides brasiliensis was diagnosed in Germany, more than 10 years after the patient's return. Diagnosis was established by the presence of yeast cells with multipolar budding in the tissue of the oral lesion. Furthermore, the fungus was grown in a liquid Leishmania culture medium. Identification of the fungus was based on morphology and genetic sequencing. Furthermore, IgG antibodies against a 43-kDa antigen of P. brasiliensis were detected in a western blot. After itraconazole therapy (400 mg day(-1)) for 4 weeks, the lesions had disappeared almost completely, but the therapy was continued for further 5 months to avoid relapse of the infection.

Case report. Fungaemia due to Penicillium piceum, a member of the Penicillium marneffei complex

Due to the inability of most Penicillium species to grow at 37 degrees C, systemic non-marneffei infections are very rare in the human host. We describe a case of fungemia due to Penicillium piceum in a female patient, who died a few days after repeated isolation of this fungus from blood cultures. The species is a member of the section Biverticillata of Penicillium, as was confirmed by rDNA Internal Transcribed Spacer (ITS) sequence data, and hence may share virulence factors with P. marneffei.

Typing and antimicrobial susceptibilities of methicillin resistant Staphylococcus aureus (MRSA) strains isolated in a hospital in Korea

Methicillin-resistant Staphylococcus aureus (MRSA) strains may cause serious nosocomial infections, including pneumonia and septicemia. The rate of methicillin-resistance among S. aureus isolates in Korea is over 50%. In this study, 90 MRSA isolates from Kyung Hee University Hospital were characterized employing bacteriophage typing, pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility testing. Eighty percent of the strains could be phage-typed. The largest group or 40% of the strains belonged to lyso group III, followed by 32% of the isolates which produced a reaction with regional additional phages. Phage type 83A was most frequently encountered, followed by phage type D11. PFGE patterns confirmed the presence of two major clusters, which comprise the isolates belonging to lyso group III and the strains that were typable with regional additional phages. The latter group also contained a number of strains that were nontypable with bacteriophages. The resistance rates to ciprofloxacin, erythromycin, tetracycline, gentamicin and clindamycin were over 94%. Strains with intermediate resistance to vancomycin strains or resistance to mupirocin were not found. In conclusion, this study demonstrates that the results of phage typing are confirmed and supplemented by PFGE data.

[Scedosporiosis of the brain with fatal outcome after traumatizatio of the foot. case report]

A 33 year old German man suffered from a wound of his foot after an accident. He developed an osteomyelitis. From wound probes Scedosporium apiospermum could be isolated for several times. Some weeks later a cerebral lesion could be diagnosed. The lesion was extirpated and again S. apiospermum could be cultured from the cerebral probes. A few weeks later the patient died and some new cerebral lesions could be diagnosed by CT-scan.

Nocardia abscessus sp. nov

Chemotaxonomic and 16S rRNA gene sequence analyses of four bacterial strains isolated from clinical material clearly demonstrated that these bacteria belong to the genus Nocardia. DNA-DNA hybridization data as well as the physiological characteristics of the isolates indicated that they are closely related and belong to a single species that differs from previously described members of the genus. The name Nocardia abscessus sp. nov. is proposed for these organisms represented by strain IMMIB D-1592T (= DSM 44432T). Strain IMMIB D-1592T exhibits 56.8 and 60.0% DNA-DNA relatedness to Nocardia asteroides ATCC 19247T and Nocardia paucivorans DSM 44386T, respectively.

Nocardia paucivorans sp. nov

Chemotaxonomic and 16S rDNA sequence analyses of an isolate from the sputa and bronchial secretions of a patient with chronic lung disease clearly demonstrated that it belongs to the genus Nocardia. DNA-DNA hybridization data, as well as the biochemical characteristics of the isolate, indicate that it belongs to a new species that differs from previously described members of the genus Nocardia. The name Nocardia paucivorans sp. nov. is proposed for this isolate and is represented by strain IMMIB D-1632T (= DSM 44386T).

The cell wall porin of the gram-positive bacterium Nocardia asteroides forms cation-selective channels that exhibit asymmetric voltage dependence

Detergent-solubilized cell wall extracts of the gram-positive, strictly aerobic bacterium Nocardia asteroides contain channel-forming activity as judged from reconstitution experiments using lipid bilayer membranes. The cell wall porin was identified as a protein with an apparent molecular mass of about 84 kDa based on SDS-PAGE. The porin was purified to homogeneity using preparative SDS-PAGE. The 84-kDa protein was no longer observed after heating in SDS buffer. The presumed dissociation products were not observed on SDS-polyacrylamide gels. The cell wall porin increased the specific conductance of artificial lipid bilayer membranes from phosphatidylcholine/phosphatidylserine mixtures by the formation of cation-selective channels, which had an average single-channel conductance of 3.0 nS in 1 M KCl. The single-channel conductance was only moderately dependent on the bulk aqueous KCl concentration, which indicated negative point charge effects on the channel properties. The analysis of the concentration dependence of the single-channel conductance using the effect of negative charges on channel conductance suggested that the diameter of the cell wall channel is about 1.4 nm. Asymmetric addition of the cell wall porin to lipid bilayer membranes resulted in an asymmetric voltage dependence. The cell wall channel switched into substates, when the cis side of the membrane, the side of the addition of the protein, had negative polarity. Positive potentials at the cis side had no influence on the conductance of the cell wall channel.

Necrotizing fasciitis caused by Vibrio vulnificus: first published infection acquired in Turkey is the second time a strain is isolated in Germany

Vibrio vulnificus, a marine vibrio, has recently been recognized as a potential human pathogen. It causes human infections with mortality rates up to 60%. Until 1991, most human isolations were reported from the USA, Japan and Taiwan. The second strain isolated in Germany is documented and a significant case of V. vulnificus infection acquired in Turkey is published for the first time.

The cell wall porin of Nocardia farcinica: biochemical identification of the channel-forming protein and biophysical characterization of the channel properties

A channel-forming protein was identified in cell wall extracts of the Gram-positive, strictly aerobic bacterium Nocardia farcinica. The cell wall porin was purified to homogeneity and had an apparent molecular mass of about 87 kDa on tricine-containing SDS-PAGE. When the 87 kDa protein was boiled for a longer time in sodium dodecylsulphate (SDS) it dissociated into two subunits with molecular masses of about 19 and 23 kDa. The 87 kDa form of the protein was able to increase the specific conductance of artificial lipid bilayer membranes from phosphatidylcholine (PC) phosphatidylserine (PS) mixtures by the formation of ion-permeable channels. The channels had on average a single-channel conductance of 3.0 nS in 1M KCl, 10mM Tris-HCl, pH8, and were found to be cation selective. Asymmetric addition of the cell wall porin to lipid bilayer membranes resulted in an asymmetric voltage dependence. The single-channel conductance was only moderately dependent on the bulk aqueous KCl concentration, which indicated point charge effects on the channel properties. The analysis of the single-channel conductance data in different salt solutions using the Renkin correction factor, and the effect of negative charges on channel conductance suggested that the diameter of the cell wall porin is about 1.4-1.6nm. Channel-forming properties of the cell wall porin of N. farcinica were compared with those of mycobacteria and corynebacteria. The cell wall porins of these members of the order Actinomycetales share common features because they form large and water-filled channels that contain negative point charges.

Typing of Nocardia farcinica by pulsed-field gel electrophoresis reveals an endemic strain as source of hospital infections

Severe postoperative wound infections caused by Nocardia farcinica were repeatedly observed in a German hospital surgical ward. A pulsed-field gel electrophoresis (PFGE) protocol was established to characterize the genetic relatedness of the bacterial isolates from these infections. All 18 isolates from postoperative infections that have occurred since 1985 belong to a common endemic genotype; organisms of this genotype were also detected in the air of two rooms of the department where these postoperative infections occurred. In contrast, two environmental isolates from another building on the same campus showed a distinct genotype. Three cases of pulmonary infections, at a department which is located in proximity to the surgical department, were also caused by the endemic type, which suggests aerogenic spread of the endemic strain to these patients. Controls consisting of epidemiologically unrelated isolates from sporadic infections in other towns belonged in each case to a different genotype. PFGE was well suited to differentiate various types of N. farcinica and revealed an endemic strain causing postoperative wound infections possibly after aerogenic transmission.

Description of Nocardiopsis synnemataformans sp. nov., elevation of Nocardiopsis alba subsp. prasina to Nocardiopsis prasina comb. nov., and designation of Nocardiopsis antarctica and Nocardiopsis alborubida as later subjective synonyms of Nocardiopsis dassonvillei

Data from chemotaxonomic and 16S ribosomal DNA sequence analyses of an isolate obtained from the sputum of a kidney transplant patient identified the isolate as a member of the genus Nocardiopsis. DNA-DNA hybridization data, as well as physiological characteristics, indicated that the isolate represents a new species of the genus Nocardiopsis, designated Nocardiopsis synnemataformans; the type strain is strain IMMIB D-1215 (= DSM 44143). In addition, DNA-DNA hybridization data, as well as the results of biochemical tests, indicated that Nocardiopsis alborubida DSM 40465T, Nocardiopsis antarctica DSM 43884T, and Nocardiopsis dassonvillei DSM 43111T represent a single species designated N. dassonvillei. We also found that Nocardiopsis alba subsp. alba DSM 43377T and N. alba subsp. prasina DSM 43845T are genetically different and therefore propose that N. alba subsp. prasina be elevated to species status as Nocardiopsis prasina comb. nov., whose type strain is strain DSM 43845.

Tsukamurella tyrosinosolvens sp. nov

Chemotaxonomic and 16S ribosomal DNA sequence analyses of four bacterial isolates from blood cultures from patients with cardiac pacemaker implants and sputa of patients with chronic lung infections clearly demonstrated that these bacteria belong to the genus Tsukamurella. DNA-DNA hybridization data, as well as the physiological characteristics of the isolates, indicate that they are closely related and belong to a single species that differs from previously described members of the genus Tsukamurella. The name Tsukamurella tyrosinosolvens sp. nov. is proposed for these isolates, and the new species is represented by strain IMMIB D-1397T (= DSM 44234T). Strain IMMIB D-1397T exhibits 53.4, 53.5, and 54.7% DNA-DNA relatedness to Tsukamurella paurometabola DSM 20162T, Tsukamurella inchonensis DSM 44067T, and Tsukamurella pulmonis DSM 44142T, respectively.

An investigation of the intra-generic structure of Rothia by pyrolysis mass spectrometry

Previous studies of the genus Rothia have indicated that members of the only species, Rothia dentocariosa, are heterogeneous and may form more than one species. To study the intrageneric taxonomic structure of the Rothia taxon eighteen strains identified as R. dentocariosa, including reference organisms from culture collections (3 strains), isolates from healthy subjects (5 strains) and from clinical sources (10 strains) were examined using pyrolysis mass spectrometry. The ordination plots of the pyrolysis data indicated that all the strains clustered in a closely related group, with the exception of three strains which out-grouped. Phenotypic testing and fatty acid data indicated that the latter three strains are probably misclassified in the genus Rothia. Reanalysis of the PyMS data including only the fifteen authentic Rothia strains indicated that ten of these organisms formed a group which included the type strain, R. dentocariosa NCTC 10917. Four out of the remaining five organisms formed a diffuse group; the remaining strain was recovered as a single member cluster. These data indicate that R. dentocariosa is heterogeneous though at present there are no suitable criteria for assigning members of this taxon to more than one species.

[Systemic Nocardia asteroides infection with endocardial involvement in a patient undergoing immunosuppressive therapy]

HISTORY

A 62 year-old male patient developed malaise, unproductive cough and high temperature (39.5 degrees C) during immunosuppressive therapy with methylprednisolon and cyclosporin A six months after kidney transplantation for glomerulonephritis.

INVESTIGATIONS

Clinical examination revealed an endophthalmitis and chest X ray a left-sided lobar pulmonic infiltration. Computed tomography and magnetic resonance imaging examination performed because of recurrent petit-mal-convulsions demonstrated multiple intracranial infiltrations. Transoesophageal echocardiography revealed floating vegetations up to 8 mm in diameter predominantly attached to the aortic valve. A total of 39 consecutive blood cultures drawn during several days remained sterile. However, Nocardia asteroides (Biovar A1) was isolated from a small cutaneous tumor excised from the right thigh.

TREATMENT AND COURSE

After initiation of a specific antibiotic treatment with imipenem/cilastatin (each 1 g three times daily), and doxycyclin (100 mg twice daily), computed tomography and magnetic resonance imaging showed a reduction in size and number of the intracranial infiltrations. Neurological symptoms were progressive despite maximal anticonvulsant therapy. The patient died 83 days after hospital admission from an epileptic state resistant to therapy.

CONCLUSION

Though nocardiosis is still rare, it should early be included in the differential diagnosis of infections in immunocompromised patients to allow timely diagnosis and therapy.

European multicentre evaluation of a commercial system for identification of methicillin-resistant Staphylococcus aureus

A commercial system for the rapid detection of methicillin-resistant Staphylococcus aureus, the BBL Crystal MRSA test (C-MRSA ID; Becton Dickinson, USA), was evaluated prospectively and compared with a polymerase chain reaction test for the presence of the mecA gene. Ten European centres tested a total of 676 isolates of Staphylococcus aureus from blood cultures. The system correctly identified 661 (97.8%) isolates within 4 h. All but three mecA gene-negative isolates (99.4% specificity) yielded a negative C-MRSA ID reaction, and 158 of 170 mecA gene-positive isolates were accurately detected (92.9% sensitivity). After repeated testing of discrepant results, sensitivity and specificity increased to 99% and 100%, respectively.

Comparison of BBL Crystal ANR ID Kit and API rapid ID 32 A for identification of anaerobic bacteria

BBL Crystal ANR ID Kit and the API System rapid ID 32 A are miniaturized identification systems for anaerobes using enzymatic tests. The incubation period of both systems is 4 hours. A comparative evaluation of the BBL Crystal Identification System Anaerobe ID Kit (Becton Dickinson Microbiology Systems, Cockeysville, USA) with anaerobes grown on Columbia and Schaedler agar plates (Becton Dickinson Microbiology Systems, Cockeysville, USA) and the API System rapid ID 32 A (BioMérieux SA, Lyon, France) with bacteria grown on Columbia agar (Becton Dickinson Microbiology Systems, Cockeysville, USA) which is recommended by the manufacturer as cultivation medium, was performed with 207 mostly fresh clinical anaerobe isolates, including 104 gram-negative bacilli, 12 gram-negative cocci, 15 gram-positive cocci, 14 gram-positive sporeforming bacilli and 62 representatives of gram-positive non-sporeforming bacilli. With supplemental testing the Crystal system with inocula from Columbia and Schaedler agar and API inoculates from Columbia agar identified to genus level 144 (69.6%), 152 (73.4%) and 109 (52.7%) isolates, respectively. Misidentification to genus level was found by Crystal from Columbia and Schaedler agar and by API from Columbia agar in 17 (8.2%), 15 (7.3%) and 12 (5.8%) isolates, respectively. 36 isolates were not determined to species level by classical anaerobic methods or the systems only identified to genus level. 26 anaerobes were not included in the database of the Crystal or API system. From the remaining 145 clinical isolates with supplemental testing, Crystal from Columbia and Schaedler agar plates correctly identified 91 (62.8%) and 102 (70.3%), respectively, and API, 69 (47.6%) isolates. For the correct identification to genus and species level of the 207 clinical isolates tested, the Crystal system from Columbia and Schaedler agar and API system from Columbia agar required supplemental testing, as specified by the manufacturer, for 39 (27.1%), 34 (22.4%) and 14 (12.8%) isolates, respectively. Among the 207 clinical isolates tested, 27 had been frozen and 26 had been lyophilized. In a comparative evaluation, the fresh isolates showed a slightly to significantly better identification rate than the frozen or lyophilized specimens in all three tests. The individual reproducibility of the Crystal ANR ID, which had been tested before the accuracy study was performed, ranged from 90.8% to 100%. The overall reproducibility was determined to be 97.3%. Time consumption studies and cost analysis did not show a significant difference between both systems, but Crystal ANR ID was found to be easier to use than API rapid ID 32.

Rapid chemotaxonomic diagnosis of human tuberculosis

65 different clinical specimens from patients suspected of being infected with Mycobacterium tuberculosis were examined by three different diagnostic methods. Two of these methods were the conventional microscopic and cultural examinations. The third, a modern chemotaxonomical method is based upon the detection of tuberculostearic acid by GC-MS analysis using selected ion monitoring (GC-MS/SIM). Comparison of the results of the GC-MS analysis with those of the conventional methods has indicated that tuberculostearic acid analysis can be used for diagnosing tuberculosis under diagnostic routine conditions. The GC-MS method is rapid, usually providing results within 20 hours or less.

Tsukamurella pulmonis sp. nov

Chemotaxonomic and 16S ribosomal DNA sequence analyses of an isolate from the sputum of a patient with a mycobacterial lung infection clearly delineated a new species of the genus Tsukamurella. This new species can be defined on the basis of genotypic and phenotypic data. The name Tsukamurella pulmonis sp. nov. is proposed for this organism; the type strain is IMMIB D-1321T (= DSM 44142T). This isolate shows 44.2 and 36.2% DNA relatedness to Tsukamurella paurometabola DSM 20162T (T = type strain) and Tsukamurella inchonensis DSM 44067T, respectively.

Recurrent bacteremia due to Brevibacterium casei in an immunocompromised patient

A case of an immunocompromised patient who experienced two episodes of septicemia caused by a coryneform bacterium is reported. Biochemical characteristics and analysis of cellular fatty acids and of cell wall components showed two identical strains of Brevibacterium casei to be responsible for these infections. The lack of easy-to-perform methods for identification may have led, in the past, to an underestimation of the role of this bacterium, especially in immunocompromised patients.

Tsukamurella inchonensis sp. nov

Chemotaxonomic and genomic 16S ribosomal DNA sequence analyses of two isolates obtained from two different clinical materials clearly delineated a new species of the genus Tsukamurella. This new species can be identified by its 16S ribosomal DNA similarity values, as well as its physiological characteristics. The name Tsukamurella inchonensis sp. nov. is proposed for these isolates, which are represented by strain IMMIB D-771T (= DSM 44067T) (T = type strain). This strain exhibits only 45% DNA relatedness to Tsukamurella paurometabola.

Lentzea gen. nov., a new genus of the order Actinomycetales

We describe a new genus of mesophilic actinomycetes, for which we propose the name Lentzea. The strains of this genus form abundant aerial hyphae that fragment into rod-shaped elements. Whole-cell hydrolysates contain the meso isomer of diaminopimelic acid and no characteristic sugar (wall chemotype III). The phospholipid pattern type is type PII (phosphatidylethanolamine is the characteristic phospholipid); the major menaquinone is MK-9. The fatty acid profile comprises saturated, unsaturated, and branched-chain fatty acids of the iso and anteiso types in addition to tuberculostearic acid (10Me-C18:0). A 16S ribosomal DNA sequence analysis revealed that the genus Lentzea is phylogenically related to the genera Actinosynnema, Saccharothrix, and Kutzneria. The type species of this genus is Lentzea albidocapillata sp. nov.; the type strain of this species is strain IMMIB D-958 (= DSM 44073).

Identification of some clinically significant actinomycetes

Early recognition of infections caused by actinomycetes tend to be highly dependent on at least a tentative diagnosis derived from microbiological tests, since the clinical symptoms can be difficult to interpret. Reliable identification of clinically significant actinomycetes depends upon the application of taxonomic techniques that are not yet widely used in clinical laboratories. The value of rapid enzyme, chemical and molecular fingerprinting techniques is exemplified by their application to the identification of representatives of clinically significant actinomycete taxa.

Cellular fatty acid methyl ester profiles as a tool in the differentiation of members of the genus Mycobacterium

The cellular fatty acid profiles of 84 strains belonging to 53 different species of the genus Mycobacterium were determined by gas liquid chromatography-mass spectrometry (GCMS). Two main types and four subtypes of fatty acid profiles were recognizable. The first main type is the G type, nominally referring to M. gordonae, members of which lack tuberculostearic acid or other 10-methyl branched-chain fatty acids, but contain normal saturated and unsaturated fatty acids. This type is further subdivided into the G alpha subtype that is characterized by 2-methyl tetradecanoic acid (2-Me-C14:0) as the only 2-methyl branched fatty acid. Strains belonging to the second main type, the T type, nominally referring to tuberculosis, contain tuberculostearic acid and other 10-methyl branched acids in addition to the normal saturated and unsaturated ones. This type has been further subdivided into three subtypes: the T alpha subtype that does not contain any 2-methyl branched fatty acids; the T beta subtype that contains both 2-methyl tetradecanoic (2-Me-C14:0) and 2,4-dimethyl tetradecanoic (2,4-DMe-C14:0) acids as 2-methyl branched fatty acids; the T gamma subtype which contains 2-methyl dodecanoic (2-Me-C12:0), 2,4-dimethyl dodecanoic (2,4-DMe-C12:0) and 2,4-dimethyl tetradecanoic (2,4-DMe-C14:0) acids as 2-methyl branched-chain acids. Fatty acid analysis showed a great homogeneity within the genus and the profiles produced were not very helpful in distinguishing between members of the genus Mycobacterium except for the identification of M. gordonae, M. kansasii, and M. gastri.

Identification of mycobacterial isolates by thin-layer and capillary gas-liquid chromatography under diagnostic routine conditions

The mycolic acid patterns of 75 strains of mycobacteria belonging to 46 different species were studied by thin-layer chromatography (TLC). Additionally, the mycolic acid pyrolytic cleavage products were determined by capillary gas-liquid chromatography (C-GLC). Eleven different patterns based on number, type and Rf values of the detected lipid spots were identified. The mycolic acid methyl ester profiles of clinical isolates were compared with those of reference strains. In this way, it was possible to relate these clinical isolates to mycobacterial groups defined by their mycolic acid profiles. The 11 patterns and the methods used are described in detail.

Phage Susceptibility and Enterotoxin Production by Staphylococcus aureus Strains Isolated from Nigerian Foods

The sensitivity of Staphylococcus aureus strains isolated from Nigerian foods to phages in the international phage sets for typing human and bovine strains of staphylococci was determined. The enterotoxigenicity of the strains was also determined using the avidin-biotin enzyme-linked immunosorbent assay and the reversed passive latex agglutination test (for staphylococcal enterotoxin D only). One hundred and five (67.7%) of 155 strains tested were susceptible to phages in both typing sets. Phages for staphylococci of human origin lysed all 105 typeable strains while those for staphylococci of bovine origin were responsible for the lysis of 92 strains. Phages in the different phage groups (mixed) were most frequently responsible for lysis, 29 (27.6%), followed by group III phages with 26 (24.8%) strains susceptible. Of the 155 strains tested, 122 (78.7%) were enterotoxigenic producing staphylococcal enterotoxins A, B, C, D, or a combination. Dried beef isolates were most enterotoxigenic (100.0%) and those from fermented milk least (68.8%). Staphylococcal enterotoxins C, B, and A were elaborated either singly or in combination by 71 (58.2%), 69 (56.6%), and 62 (50.8%) strains, respectively. It was concluded that a majority of staphylococcal strains isolated from Nigerian foods originated from humans and their high enterotoxigenicity could be a health risk to consumers.

Detection of enterotoxigenicity of Staphylococcus aureus strains: a comparative use of the modified Ouchterlony precipitation test, reversed passive latex agglutination test, and avidin-biotin ELISA

The avidin-biotin enzyme-linked immunosorbent assay (ELISA), reversed passive latex agglutination (RPLA) test, and the modified Ouchterlony precipitation test (MOPT) were compared in detecting enterotoxin production by Staphylococcus aureus strains. A total of 1015 strains isolated from human beings, animals, and foods were tested for staphylococcal enterotoxins A (SEA), B (SEB), and C (SEC). Of these, 495 (48.8%), 467 (46.0%), and 204 (20.1%) were classified as enterotoxigenic by the ELISA, RPLA test, and MOPT, respectively. The difference in the number of strains classified as enterotoxigenic by the ELISA and RPLA test was not significant (P > or = 0.05; chi 2), but both tests detected significantly (P < 0.001; chi 2) more enterotoxigenic strains than the MOPT. The combined use of the three assay systems classified 258 (25.4%), 278 (27.4%), and 263 (25.9%) of 1015 strains tested as positive for SEA, SEB, and SEC, respectively. However, the three systems were all positive in only 29.1% of SEA-producing strains, 32.0% of SEB-producing strains, and 25.1% of SEC-producing strains. The MOPT was negative when the corresponding ELISA and RPLA test were positive (46.9% for SEA, 43.5% for SEB, and 40% for SEC); the RPLA test was negative when the corresponding ELISA was positive (10.5% for SEA, 15.5% for SEB, and 25.5% for SEC); and the ELISA was negative when the RPLA test was positive (13.6% for SEA, 9.0% for SEB, and 9.5% for SEC). All factors considered, the RPLA test appears most suitable for quantitatively screening large numbers of strains for staphylococcal enterotoxins.

Phage susceptibility, enterotoxigenicity and antibiograms of Staphylococcus aureus strains isolated from human wounds and diarrhoea

The phage types, enterotoxigenicity and antibiograms of Staphylococcus aureus strains isolated from human diarrhoea and skin wounds in Nigeria were determined. Of 194 strains tested, 140 (72.2%) were typable using a combination of phages in the International Phage Set (IPS) for human strains of S. aureus and the bovine phage set. IPS phages lysed 118 (60.8%) strains while 96 (49.5%) were susceptible to bovine phages. S. aureus strains from adult diarrhoea were significantly (P less than or equal to 0.01; x2) more sensitive to bovine phages (52.8%) than to IPS human phages (16.7%). Strains isolated from wounds were however significantly (P less than or equal to 0.001; x2) more susceptible to IPS human phages (72.9%) than to bovine phages (41.5%). Phage group III strains were predominant amongst diarrhoeal isolates while wound strains were most susceptible to group II phages. Phage 119, a bovine phage, lysed all 19 strains of diarrhoeal origin sensitive to group M phages but all wound strains were resistant. Overall, 132 (68.0%) strains were enterotoxigenic producing staphylococcal enterotoxins A (SEA), B (SEB), C (SEC) or a combination of these. A majority of diarrhoeal strains elaborated SEC while SEB production was predominant amongst wound strains. Of the eight antimicrobial agents used, S. aureus strains were most resistant to penicillin (71.6%) and least to sulfamethoxazole/trimethoprim (1.0%). Occurrence of resistance to one or more antibiotics was higher amongst wound strains (97.5%) than amongst strains isolated from diarrhoea (52.6%). It was concluded that bovine phage 119 may be a useful epidemiologic marker for S. aureus strains of bovine origin associated with human diarrhoea in Nigeria. It is however difficult to ascribe any aetiological significance to these strains because other enteropathogens not assayed for may have been present.

Actinomycete infections in humans--a review

Diseases caused by pathogenic aerobic and facultatively anaerobic actinomycetes differ considerably with respect to their etiology, pathogenesis, clinical appearance and epidemiology. Facultatively anaerobic (fermentative) actinomycetes may not only be involved etiologically in the three classical forms of cervicofacial, thoracic and abdominal actinomycoses, but also in infections of the female genital organs, the eye, the tissue adjacent to dental implantation elements and tooth extraction wounds. The species distribution of the fermentative actinomycetes isolated from these conditions varied to a certain, but characteristic, extent, as did the concomitant actinomycotic flora. The sex ratio reported for human Actinomyces infections (male:female = 3:1) appeared to be restricted to actinomycotic abscesses and empyemas. The prevailing pathogenic, obligately aerobic actinomycete species in Germany was found to be Nocardia farcinica followed by Nocardia asteroides. The comparatively high incidence of N. farcinica infections was chiefly due to the occurrence of nosocomial postoperative wound infections by this pathogen observed in two German hospitals. Besides surgical treatment, immunosuppressive treatment appeared to be the most common factor predisposing for nocardiosis. Recent observations strongly suggested that the spectrum of human nocardial infections in Germany has been changing, as regards the overall incidence, the prevalence of N. farcinica, the sex ratio, the mean age of patients, as well as the role of N. farcinica as a possibly important nosocomial pathogen.

Production of toxic shock syndrome toxin-1 (TSST-1) by Staphylococcus aureus strains isolated from humans, animals and foods in Nigeria

The production frequency of toxic shock syndrome toxin-1 (TSST-1) amongst Staphylococcus aureus strains isolated from humans, animals and foods in Nigeria was investigated. Of 1015 strains tested, 120 (11.8%) were positive for TSST-1. Thirty one (16.0%) of 194 strains from human diarrhoea and wounds were positive compared to 47 (7.1%) of 666 isolates from eight animal species. Goat strains were most often positive for this toxin (17.0%). A total of 42 (27.1%) of 155 strains from foods were positive for TSST-1. Regardless of source, phage non-typable strains (48.3%) were most common amongst TSST-1 producers followed by strains sensitive to phages in several groups (mixed), 18.3%, and phage group III strains (17.5%). Only 6 were phage group I strains (5.0%). TSST-1 producing strains were mostly resistant to penicillin. Eighty-four (70.0%) TSST-1 producers were also enterotoxigenic with staphylococcal enterotoxin C (SEC) most frequently elaborated as 46 (38.9%) strains were positive. However, 42 (35.5%) and 39 (32.5%) strains producing TSST-1 were also positive for SEA and SEB, respectively. It was concluded that TSST-1 producing strains of S. aureus are widespread in humans, animals and foods in Nigeria and such distribution may play some role in the epidemiology of toxic shock syndrome, the prevalence of which is currently unknown in the environment.

Lytic activities, protein profiles and morphologic characteristics of new bacteriophages isolated from canine and human Staphylococcus aureus strains

The lytic activity, protein profile and morphology of five newly isolated phages from canine Staphylococcus aureus strains and one from a human S. aureus strain were compared with those of selected phages in the international phage sets (IPS). Five canine phages lysed 57 (76.0%) of 75 canine isolates of Staphylococcus aureus from Nigeria at routine test dilution (RTD) while 34 (IPS) phages typed only 31 (41.3%) strains at RTD or/and 100-RTD. The new human phage lysed 11 (14.7%) of 75 strains isolated from human diarrhoea. The new phages were readily propagated, specific in activity and stable during storage at 4 degrees C. Prominent proteins detected by SDS-PAGE indicated similarities between some of the phages but one canine phage was distinctly different, as was its morphology which was an isometric head with a short tail compared to oval heads and long tails which characterized others. IPS phages in the same serologic group had similar protein profiles but no correlation was observed with lytic groups. The use of protein profile and electron micrographs allowed classification of the phages into serogroups. It is concluded that the newly isolated canine phages could be very useful in typing Nigerian canine strains of S. aureus.

Disseminated actinomycosis due to Actinomyces meyeri and Actinobacillus actinomycetemcomitans

A 44-year-old man presented with pulmonary lesions and neurological symptoms suggestive of lung carcinoma with cerebral metastases. He had non-specific chest X-ray findings since 6 years and he also suffered from relapsing purulent skin lesions which resolved spontaneously or by short courses of antibiotic treatment. When corticosteroids were given, multiple subcutaneous swellings developed that spontaneously ruptured. The pus contained Actinomyces meyeri and Actinobacillus actinomycetemcomitans. On operation, the intracerebral lesions appeared to be abscesses and the same bacteria were cultured as from the skin lesions. Bronchoscopical examination did not reveal a diagnosis. Amoxicillin was given for 12 months and the patient recovered.