Corynebacterium Propinquum Research Articles

NirK and nirS Nitrite reductase genes from non-agricultural forest soil bacteria in Thailand

The genetic heterogeneity of the nitrite reductase gene (nirK and nirS) fragments from denitrifying prokaryotes in a non-agricultural forest soil in Thailand was investigated using soil samples from the Plant Germplasm-Royal Initiation Project area in Kanchanaburi Province, Thailand. Soil bacteria were screened for denitrification activity and 13 (from 211) positive isolates were obtained and further evaluated for their ability to reduce nitrate and to accumulate or reduce nitrite. Three species with potentially previously unreported denitrifying activities were recorded. Analysis of the partial nirK and nirS sequences of these 13 strains revealed a diverse sequence heterogeneity in these two genes within the same environment and even potentially within the same host species, the potential existence of lateral gene transfer and the first record of both nirK and nirS homologues in one bacterial species. Finally, isolates of two species of bacteria (Corynebacterium propinquum and Micrococcus lylae) are recorded as denitrifiers for the first time.

<I>Corynebacterium propinquum</I>呼吸器感染症の3症例

Corynebacterium propinquum, which is included in Corynebacterium group ANF-3, exists as a commensal in the oral flora. This organism has not yet been fully recognized as a respiratory pathogen. We previously reported that the first case with respiratory infection caused by C. propinquum. On the other hand, Corynebacterium pseudodiphtheriticum is recognized as a causative organism in respiratory infections. Recently we experienced two cases with C. propinquum respiratory infections in our hospital. Three types of the onset such as a community-acquired infection, a hospital-acquired infection, and a nursing home acquired infections were observed. Our analysis indicated that gram staining of the purulent sputum is an essential tool to evaluate whether C. propinquum is a respiratory pathogen or not, because this organism is a commensal bacteria.

Nondiphtherial Corynebacterium species isolated from clinical specimens of patients in a university hospital, Rio de Janeiro, Brazil

Over a five-year period, 163 strains of Corynebacterium sp. were recovered from different clinical specimens of patients from a Brazilian University hospital. Genitourinary tract and intravenous sites specimens were the most frequent sources of corynebacteria (46.62%). Corynebacterium amycolatum (29.55%), Corynebacterium minutissimum (20.45%) and Corynebacterium pseudodiphtheriticum (13.63%) were the predominant species found in genitourinary tract. C. minutissimum (24.14%) and Corynebacterium propinquum (17.24%) in surgical and/or other skin wounds and abscesses; Corynebacterium xerosis (25%), C. amycolatum (21.87%) and C. pseudodiphtheriticum (18.75%) in intravenous sites; C. pseudodiphtheriticum (33.33%) and C. propinquum (33.33%) in lower respiratory tract. Microorganisms were all susceptible to vancomycin and most of the species was predominantly resistant to b-lactams. Antimicrobial susceptibility patterns of corynebacteria were not predictable. Multiple antibiotic resistance observed in C. jeikeium was also found among C. xerosis, C. minutissimum, C. afermentans, C. propinquum, C. amycolatum and C. pseudodiphtheriticum strains. Data suggest awareness of clinicians and microbiologists to nosocomial infections especially due to antimicrobial multiresistant strains of Corynebacterium sp.

Coryneform bacteria isolated from blood cultures and their antibiotic susceptibilities.

We aimed to determine the types of corynebacteria isolated from the blood of patients at Gaziantep University Hospital, Turkey, and their antibiotic susceptibilities. Between February 1999 and June 2001, 3530 blood samples were cultured, of which 915 were found to be positive, and these were further investigated in the bacteriology laboratory. Among positive blood cultures, coryneform bacteria were identified in 31 (3.4%) isolates. Of these, 16 (51.6%) were Corynebacterium jeikeium, six (19.4%) were Corynebacterium striatum, four (12.9%) were Corynebacterium amycolatum, two (6.5%) were Cellulomonas species, two (6.5%) were Corynebacterium afermentans and one isolate (3.2%) was Corynebacterium propinquum. Antibiotic susceptibility tests showed that C. jeikeium was resistant to various antibiotics, whereas all isolates were susceptible to vancomycin and teicoplanin. This study illustrates the importance of taking coryneform bacteria into consideration when culturing blood samples. The need to identify the species and determine its antibiotic sensitivity is emphasized.

Pleural Effusion Due toCorynebacterium Propinquumin a Patient with Squamous Cell Carcinoma

Pleural Effusion Due to<i>Corynebacterium Propinquum</i>in a Patient with Squamous Cell Carcinoma

Species identities and antimicrobial susceptibilities of corynebacteria isolated from various clinical sources.

Over a 14-month period, 415 clinical isolates of coryneform gram-positive rods were recovered from various sources and identified to the species level according to recent identification schemes. Corynebacterium urealyticum, Corynebacterium striatum, Corynebacterium amycolatum, and Corynebacterium jeikeium predominated, accounting for 63% of all isolates. Corynebacterium accolens, Corynebacterium striatum, Corynebacterium argentoratense, Corynebacterium propinquum and Corynebacterium pseudodiphtheriticum were mostly recovered from the respiratory tract, whereas Corynebacterium afermentans, CDC group G, and Corynebacterium jeikeium were mainly isolated from blood. None of the isolates was identified as Corynebacterium diphtheriae or Corynebacterium xerosis. Ampicillin resistance was detected in Corynebacterium jeikeium (96%) and Corynebacterium urealyticum (99%) and varied among Corynebacterium amycolatum (56%) and CDC group G (26%). These data emphasize the need for an accurate identification of coryneform organisms at the species level and for antimicrobial susceptibility testing of these organisms.

Proposal ofCorynebacterium propinquumsp. nov. forCorynebacteriumgroup ANF-3 strains

Chemotaxonomic and genomic studies were performed on seven Corynebacterium group ANF-3 strains isolated from human sources. All these strains possess cell wall component type IV (meso-diaminopimelic acid, arabinose and galactose), corynemycolic acids and a G+C content of DNA of 57 to 59 mol%. These results confirm that they can be placed in the genus Corynebacterium. Six of these strains were found to constitute a tight hybridization group distinct from named Corynebacterium species or related organisms. This genomic group constitutes a new species which can be identified within the genus Corynebacterium by ribotyping or phenotypic tests and for which the name Corynebacterium propinquum is proposed. The type strain is strain B 77159 (= Collection of the Institut Pasteur CIP 103792).