Characterization and antimicrobial susceptibility of one antibiotic-sensitive and one multidrug-resistant Corynebacterium kroppenstedtii strain isolated from patients with granulomatous mastitis.

Human infections associated with Corynebacterium kroppenstedtii are rarely reported, and this organism is usually described as antibiotic sensitive. Almost all published cases of C. kroppenstedtii infections have been associated with breast pathology in women and have been described in New Zealand, France, Canada, India and Japan. Here we describe the microbiologic characteristics of two strains isolated from two women diagnosed of granulomatous mastitis in Spain. One C. kroppenstedtii isolate was antibiotic sensitive while the other was multidrug resistant. Biochemical identification was possible using a wide battery of methods including API Coryne V2.0, API Strep, API NH, API NE, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene amplification and sequencing. Antimicrobial susceptibility to 28 antibiotics as determined by Etest showed one isolate being sensitive to benzylpenicillin, ciprofloxacin, moxifloxacin, gentamicin, vancomycin, clindamycin, tetracycline, linezolid and rifampin. The second isolate showed resistance to ciprofloxacin, moxifloxacin, clindamycin, tetracycline and rifampin. The multidrug-resistant isolate contained the erm(X), tet(W), cmx, aphA1-IAB, strAB and sul1 resistance genes known from the R plasmid pJA144188 of Corynebacterium resistens. These genes were absent in the genome of the antibiotic-sensitive isolate. This report confirms the tropism of this microorganism for women's breasts and presents the first description of a multidrug-resistant C. kroppenstedtii strain.

Phenotypic, molecular characterization, antimicrobial susceptibility and draft genome sequence of Corynebacterium argentoratense strains isolated from clinical samples.

During a 12-year period we isolated five Corynebacterium argentoratense strains identified by phenotypic methods, including the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and 16S rRNA gene sequencing. In addition, antimicrobial susceptibility was determined, and genome sequencing for the detection of antibiotic resistance genes was performed. The organisms were isolated from blood and throat cultures and could be identified by all methods used. All strains were resistant to cotrimoxazole, and resistance to ß-lactams was partly present. Two strains were resistant to erythromycin and clindamycin. The draft genome sequences of theses isolates revealed the presence of the erm(X) resistance gene that is embedded in the genetic structure of the transposable element Tn5423. Although rarely reported as a human pathogen, C. argentoratense can be involved in bacteraemia and probably in other infections. Our results also show that horizontal transfer of genes responsible for antibiotic resistance is occurring in this species.

Dermabacter hominis: a usually daptomycin-resistant gram-positive organism infrequently isolated from human clinical samples.

During a 12-year period, Dermabacter hominis was isolated from 21 clinical samples belonging to 14 patients attending a tertiary hospital in León, Spain. Samples included blood cultures (14), peritoneal dialysis catheter exit sites (three), cutaneous abscesses (two), an infected vascular catheter (one) and a wound swab (one). Identification was made by API Coryne™ V2.0, Biolog™ GP2 and 16S rRNA gene amplification. Six febrile patients had positive blood cultures (one, two or three sets) and all of them were treated with teicoplanin (two patients), vancomycin, ampicillin plus gentamicin, amoxicillin/clavulanic acid and ciprofloxacin (one each). An additional patient with a single positive blood culture was not treated, the finding being considered non-significant. In the remaining seven patients the organism was isolated from a single specimen and three of them received antimicrobial treatment (ciprofloxacin, ceftriaxone plus vancomycin and amoxicillin/clavulanic acid). At least ten patients had several underlying diseases and conditions, and no direct mortality was observed in relation to the isolated organism. All isolates were susceptible to vancomycin, rifampin and linezolid. Resistance to other antibiotics varied: erythromycin (100%), clindamycin (78.5%), ciprofloxacin (21.4%) and gentamicin, quinupristin-dalfopristin, benzylpenicillin and imipenem 7.1% each. Thirteen isolates were highly resistant to daptomycin with MICs ranging from 8 to 48 (MIC90 = 32 mg/L); only one was daptomycin-sensitive (MIC = 0.19 mg/L).

[Cavited pneumonia with Mycobacterium gastri positive culture smear]. / Neumonía cavitada con cultivo de esputo positivo para Mycobacterium gastri.

BACKGROUND: Mycobacterium gastri is an atypical non pigmented mycobacteria infrequent in clinical practice. Few reports have been published about infections caused by microorganism, and only three of them, all before 1986, were respiratory infections. METHODS: We report a case of cavitary pneumonia with sputum culture positive for Mycobacterium gastri, and we review the previous published cases. RESULTS: We describe a 79-years old man diagnosed of chronic obstructive pulmonary disease (COPD), with chronic respiratory failure, hypertension, Alzheimer's disease and multiple myeloma IgG lambda type IIA, with multiple previous admissions in our institution. He has again admitted because of an acute episode of cough and fever. The chest radiography demonstrated a right lower cavitary infiltrate, and the sputum culture showed growth of Mycobacterium gastri. DISCUSSION: We report a case of cavitary pneumonia in an immunocompromised patient caused by M. gastri resistant to isoniazid and pyrazinamide with fatal evolution. All of the cases previously described had a favourable outcome with the different treatment used.

Identification of the emerging skin pathogen Corynebacterium amycolatum using PCR-amplification of the essential divIVA gene as a target.

The actinomycete Corynebacterium amycolatum is a saprophytic bacterium usually associated with the human skin, but it is at present considered an emergent pathogen as it is isolated from nosocomial settings from samples of immunosuppressed patients. The conventional method to distinguish C. amycolatum from closely related species is mainly based on phenotypic or chemotaxonomic studies. We developed a molecular method to identify rapidly C. amycolatum based on the use of different primers for amplification of the cell division divIVA gene using conventional or real-time PCR. This technique was used for the first time to distinguish C. amycolatum from the closely related Corynebacterium striatum, Corynebacterium minutissimum and Corynebacterium xerosis, without the requirement of further molecular analysis. The suitability of the identification method was tested on 51 clinical isolates belonging to the nonlipophilic fermentative group of corynebacteria (cluster C. striatum/C. amycolatum), which were accurately characterized by sequencing a 0.8 kb fragment of the 16S rRNA gene.

Bacteriemia por Campylobacter fetus en paciente inmunocompetente / Campylobacter fetus bacteremia in immunocompetent patient

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[Corynebacterium D2 as a ureolytic organism: report of 5 cases]. / Corynebacterium D2 como germen ureolítico: a propósito de cinco casos.

Corynebacterium D2, a saprophytic microorganism of skin, causes alkaline encrusted cystitis in patients with a previous bladder injury. In 5 patients that had presented this nosological entity, these gram-positive rods were isolated in urine cultures and calculi. Four patients had undergone urological instrumentation maneuvers and one patient (female) had a history of recurrent cystitis from gram-negative bacteria. Corynebacterium D2 grows slowly and under certain conditions, as those described above, must be considered pathological despite counts of less than 100,000/ufc-cc. It is ureolytic and highly resistant to antibiotics. The synergistic effects of antimicrobials, acetohydroxamic acid and transurethral resection of the lithiasic plaques achieve satisfactory treatment of alkaline encrusted cystitis from Corynebacterium D2.