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Corynebacterium striatum: a diphtheroid with pathogenic potential.

Although nondiphtherial corynebacteria are ubiquitous in nature and commonly colonize the skin and mucous membranes of humans, they rarely account for clinical infection. Corynebacterium striatum has rarely been reported to be a pathogen, causing pleuropulmonary infections and bacteremia in only immunocompromised or anatomically altered patients. We noted C. striatum to be the infecting pathogen or copathogen in six patients. To our knowledge, this report describes the first cases of C. striatum causing infection of exist sites of central venous catheters, thrombophlebitis associated with central venous catheters, conjunctivitis, and chorioamnionitis as well as a possible pathogen contributing to peritonitis and pyogenic granuloma. Unlike Corynebacterium jeikeium, which is highly resistant to beta-lactam agents, aminoglycosides, and quinolones, all strains of C. striatum isolated from the patients described in this report were susceptible to vancomycin and aminoglycosides, and all strains except one were susceptible to penicillin G, imipenem, and ciprofloxacin. C. striatum should be recognized as a potential pathogen in both immunocompromised and normal hosts in the appropriate circumstances, and appropriate antimicrobial therapy can quickly lead to resolution of infection.

Adult↗

Mycobacterium chelonei masquerading as Corynebacterium in a case of infectious keratitis: a diagnostic dilemma.

PURPOSE: The diagnosis of Mycobacterium keratitis can often be missed both clinically and microbiologically and this report highlights one such case. METHODS: Review of medical and microbiological records. RESULTS: We report a case of Mycobacterium keratitis in a 25-year-old man that was misdiagnosed as Corynebacterium keratitis at initial presentation. Presence of partially stained and beaded bacilli in a Gram-stained smear of repeat corneal scrapings raised the suspicion of an unusual organism. Ziehl-Neelsen staining of the decolorized Gram-stained smear and subculture on Löwenstein-Jensen medium helped us to establish the diagnosis. CONCLUSIONS: A high degree of suspicion needs to be maintained, especially in cases in which (a) there is a history of corneal trauma involving a foreign body, (b) the Gram-stained smear of corneal scrapings shows a paucity of organisms and the presence of partially stained and beaded bacilli in the presence of confluent growth of colonies resembling those of Corynebacterium, and (c) a typical corneal feature like "cracked windshield" stromal lesion is seen, to avoid such a misdiagnosis. Inclusion of a Löwenstein-Jensen culture at the initial presentation, especially when the clinical presentation is atypical, as seen in this case, will lead to an early diagnosis.

Adult↗

Four-valve endocarditis caused by corynebacterium CDC group I1.

I have reported a case of fulminant four-valve endocarditis in an intravenous drug abuser caused by the unusual Corynebacterium CDC group I1. Corynebacteria generally cause endocarditis only on damaged and prosthetic valves; fewer than ten cases have been reported on previously normal valves and fewer still in drug abusers. This is the first reported case of endocarditis caused by Corynebacterium CDC group I1.

Acute Disease↗

Profile analysis of total mycolic acids from skin corynebacteria and from named Corynebacterium strains by gas-liquid chromatography and gas-liquid chromatography/mass spectrometry.

Gas-liquid chromatography (g.l.c.) was investigated as a potential tool in the classification and identification of Cornyebacterium strains isolated from human skin, on the basis of the g.l.c. profile of the trimethylsilyl derivatives of their mycolic acid methyl esters. The g.l.c. patterns of five skin corynebacteria were compared with those of reference strains Corynebacterium diphtheriae PW8 and Corynebacterium xerosis NCTC 9755 and NCTC 7929. Further compositional information was obtained by gas-liquid chromatography/mass spectrometry (g.l.c./m.s.) of mycolates from C. diphtheriae PW8 and two of the skin isolates. In addition to identifying and examining the individual mycolate species and comparing the differences in mycolate profile between skin corynebacteria and between reference strains, a limited assessment was made of the possibility of distinguishing between organisms at both strain and species levels on the basis of mycolic acid composition as revealed by g.l.c. "fingerprinting".

Chromatography, Gas↗

The DNA sequence and minimal replicon of the Corynebacterium glutamicum plasmid pSR1: evidence of a common ancestry with plasmids from C. diphtheriae.

The complete nucleotide sequence of pSR1, a 3 kb multicopy cryptic plasmid from Corynebacterium glutamicum ATCC 19223 has been determined. pSR1 is unrelated to the 4.4 kb Brevibacterium lactofermentum plasmid pBL1 and shows no DNA sequence conservation with plasmids from Staphylococcus. Transposon insertion and deletion mutants located the minimal replicon to within a 2.1 kb NcoI-BclI restriction fragment. This region contains a single large open reading frame, ORF2, flanked at the 5' end by a series of inverted repeat sequences which may modulate its expression, and at the 3' end by a region which may contain a replication origin. ORF2 (position 1633-2636) with a maximum coding potential of 36 kDa is essential for pSR1 replication and was designated the rep gene. The predicted ORF2 protein product exhibits 47% identity over a length of 343 amino acids with a replication-associated ORF in the C. diphtheriae plasmid pNG2, many of the changes being in the third base position. This observation suggests that pSR1 and pNG2, which are two plasmids from environmentally separated Corynebacterium species, may share a common ancestral rep gene.

Amino Acid Sequence↗

[Four cases of respiratory tract infections caused by Corynebacterium pseudodiphtheriticum].

Four cases of respiratory tract infections caused by Corynebacterium pseudodiphtheriticum were reported. The first two patients developed pneumonia with Corynebacterium pseudodiphtheriticum during steroid therapy used against their underlying diseases. The other two patients had acute exacerbation of chronic pulmonary diseases caused by C. pseudodiphtheriticum. These four patients improved by antibiotic therapy. Though nondiphtheria corynebacteria are regarded as "normal flora" when they are isolated from sputum, they should be recognized as potential pathogens.

Aged↗

[A case of community-acquired pneumonia caused by Corynebacterium propinquum].

Corynebacterium propinquum, which is classified as Corynebacterium ANF-3, has not yet been described as a cause of the respiratory infections. In this paper, we reported a case of 67-year-old immunocompetent male with community-acquired pneumonia caused by C. propinquum. Our study suggested that Gram staining of the pulurent sputum was the most important diagnostic tool to determine the pathogenecity of this organism.

Aged↗

Arcanobacterium haemolyticum phospholipase D is genetically and functionally similar to Corynebacterium pseudotuberculosis phospholipase D.

Arcanobacterium haemolyticum, a pathogen of the human upper respiratory tract and other systems, has been reported to produce soluble toxins, including a phospholipase D (PLD). We confirmed production of PLD by this organism and cloned and sequenced pld. Arcanobacterial PLD (PLD-A) was found to be a protein of approximately 31.5 kDa with a pI of approximately 9.4. Cosmid cloning, followed by subcloning into phagemid pBluescriptIISK+, yielded Escherichia coli(pAh140), a recombinant with a gene product corresponding to PLD-A. Evidence of PLD activity was found by three assays in supernatant fluid of cultures of E. coli(pAh140) and A. haemolyticum, but not in E. coli(pBluescriptIISK+). Experiments to determine if this protein was secreted were not conducted, but previous work with PLD from Corynebacterium pseudotuberculosis suggested that the presence of the enzyme in culture supernatant fluids was due to lysis of E. coli rather than to active transport. Antibodies in polyclonal sera from goats immunized with native or recombinant PLD-A neutralized native and recombinant PLD-A activity, and antibodies against native or recombinant PLD from C. pseudotuberculosis (PLD-P) partially neutralized native and recombinant PLD-A. Antibodies prepared against recombinant PLD-A labelled both recombinant and native PLD-A in Western blots (immunoblots) and dot blots, but antibodies against PLD-P did not. Sequencing of the insert in pAh140 revealed an open reading frame of 930 bp coding for 309 amino acids, including a putative signal sequence of 26 amino acids (3.2 kDa, determined on the basis of homology with the 24-amino-acid signal sequence of pld from C. pseudotuberculosis bv. ovis) and the mature PLD protein (31.5 kDa). Sequence comparisons of coding regions revealed 65% DNA homology with pld genes from C. pseudotuberculosis and Corynebacterium ulcerans. Comparison of amino acid sequences revealed 64% homology of PLD-A both with PLD-P and with PLD produced by C. ulcerans.

Amino Acid Sequence↗

Analysis of novel zinc-binding proteins in the cell wall of Corynebacterium diphtheriae.

UNLABELLED: Zinc is a critical nutrient for all living organisms, including bacterial pathogens such as Corynebacterium diphtheriae, the causative agent of the severe human respiratory disease diphtheria. As such, zinc acquisition is essential for many pathogens to cause disease. We previously showed that the zinc-regulated ABC transporter encoded by the znu locus is one of several zinc uptake systems that support the growth of C. diphtheriae in zinc-limited medium. In this study, we examine the function and cellular localization of components encoded by the znu gene cluster, which includes the ZnuABC transporter and the novel membrane and cell wall proteins ZnuE, ZnuF, and ZnuG. Deletion of znuE results in reduced growth in zinc-limited media, suggesting a role in zinc uptake. While the growth of znuF and znuG mutants was not affected in zinc-limited medium, deletion of these two genes in a mutant also lacking the znuABC transporter restored growth to wild-type levels, suggesting that ZnuF and ZnuG exert an unusual modulating effect on zinc import. ZnuE, ZnuF, and ZnuG possess a unique motif that is associated with Zn binding as demonstrated by thermal shift assays, targeted mutagenesis, and structural analysis. Although ZnuF and ZnuG are both present in the cell wall, only ZnuG contains a sortase recognition signal that is critical for localizing proteins to the cell wall. Furthermore, ZnuF localization does not require any of the six known sortase enzymes in C. diphtheriae, suggesting a novel localization mechanism. IMPORTANCE: Zinc is a critical nutrient required by many bacterial pathogens. While the function of multiple zinc importer systems has been previously characterized in Corynebacterium diphtheriae, the transporter encoded by the znu gene cluster includes components not found in other metal transport systems. In this report, we examined the roles of three components of the znu gene cluster, ZnuE, ZnuF, and ZnuG, and show that these proteins all possess a putative zinc-binding domain and have varying effects on growth in zinc-limited medium. Additionally, ZnuF uses a novel mechanism for cell wall localization. This study further expands our understanding of C. diphtheriae zinc import and points to a potentially novel mechanism for the localization of cell wall proteins.

Corynebacterium diphtheriae↗

Utilization of host iron sources by Corynebacterium diphtheriae: identification of a gene whose product is homologous to eukaryotic heme oxygenases and is required for acquisition of iron from heme and hemoglobin.

Corynebacterium diphtheriae was examined for the ability to utilize various host compounds as iron sources. C. diphtheriae C7(-) acquired iron from heme, hemoglobin, and transferrin. A siderophore uptake mutant of strain C7 was unable to utilize transferrin but was unaffected in acquisition of iron from heme and hemoglobin, which suggests that C. diphtheriae possesses a novel mechanism for utilizing heme and hemoglobin as iron sources. Mutants of C. diphtheriae and Corynebacterium ulcerans that are defective in acquiring iron from heme and hemoglobin were isolated following chemical mutagenesis and streptonigrin enrichment. A recombinant clone, pCD293, obtained from a C7(-) genomic plasmid library complemented several of the C. ulcerans mutants and three of the C. diphtheriae mutants. The nucleotide sequence of the gene (hmuO) required for complementation was determined and shown to encode a protein with a predicted mass of 24,123 Da. Sequence analysis revealed that HmuO has 33% identity and 70% similarity with the human heme oxygenase enzyme HO-1. Heme oxygenases, which have been well characterized in eukaryotes but have not been identified in prokaryotes, are involved in the oxidation of heme and subsequent release of iron from the heme moiety. It is proposed that the HmuO protein is essential for the utilization of heme as an iron source by C. diphtheriae and that the heme oxygenase activity of HmuO is involved in the release of iron from heme. This is the first report of a bacterial gene whose product has homology to heme oxygenases.

Amino Acid Sequence↗

Construction and consequences of directed mutations affecting the hemin receptor in pathogenic Corynebacterium species.

Genes encoding an ATP-binding cassette transporter system involved in hemin iron utilization from Corynebacterium ulcerans were cloned and characterized. The genes are homologous to a hemin transport system previously identified in Corynebacterium diphtheriae. Disruption of the hmuT gene, which encodes the putative hemin receptor, resulted in greatly reduced ability of C. ulcerans to use hemin or hemoglobin as an iron source. Inactivation of hmuT in C. diphtheriae by site-specific recombination had no effect on hemin utilization, which suggests that C. diphtheriae has an additional system for transporting hemin.

ATP-Binding Cassette Transporters↗

Aerobic and anaerobic bacterial counts of nasal washings: presence of organisms resembling Corynebacterium acnes.

Watson, Elinor D. (Washington University, St. Louis, Mo.), Nanci J. Hoffman, Richard W. Simmers, and Theodor Rosebury. Aerobic and anaerobic bacterial counts of nasal washings: Presence of organisms resembling Corynebacterium acnes. J. Bacteriol. 83:144-148. 1962.-Aerobic and anaerobic colony counts in blood agar were made of 40 samples of nasal washings from five healthy adults. The anaerobic counts were consistently and significantly higher, in line with findings previously reported by others for skin, saliva, and feces. Catalase-forming diphtheroids utilizing lactate anaerobically, tentatively identified as members of the Corynebacterium acnes group, were conspicuous in the anaerobic cultures.

Adult↗

IDENTIFICATION OF CORYNEBACTERIUM DIPHTHERIAE WITH FLUORESCENT ANTIBACTERIAL REAGENTS.

Moody, Max D. (Communicable Disease Center, Atlanta, Ga.) and Wallis L. Jones. Identification of Corynebacterium diphtheriae with fluorescent antibacterial reagents. J. Bacteriol. 86:285-293. 1963.-Conditions are described whereby fluorescent-antibody reagents could be prepared and used to identify Corynebacterium diphtheriae in pure and mixed cultures and in clinical materials. The use of O and OK antigens for immunization of rabbits to prepare the antibody was compared. The most satisfactory reagents were those made from serum of rabbits injected with live (OK) suspensions of C. diphtheriae. Such fluorescent reagents were used successfully in direct and indirect fluorescent-antibody tests to identify both toxinogenic and atoxinogenic C. diphtheriae but not to differentiate the two kinds of organisms.

Animals↗

SIALIDASE (NEURAMINIDASE) OF CORYNEBACTERIUM DIPHTHERIAE.

Warren, Leonard (National Institute of Arthritis and Metabolic Diseases, Bethesda, Md.) and C. W. Spearing. Sialidase (neuraminidase) of Corynebacterium diphtheriae. J. Bacteriol. 86:950-955. 1963.-The characteristics of a sialidase produced by Corynebacterium diphtheriae were studied. The enzyme was partially purified from preparations of diphtheria toxin on a column of Sephadex G-75. By this means the lethal factor of diphtheria toxin was separated, in part, from the sialidase activity. There appeared to be a close immunological relationship between the sialidases of C. diphtheriae and clostridia, since a preparation of diphtheria antitoxin was as effective an inhibitor of diphtheria sialidase as of the sialidase of three species of clostridia. Conversely, antitoxin to clostridia inhibited diphtheria sialidase. Diphtheria antitoxin was essentially inactive toward influenza virus sialidase, and was completely inactive against purified sialidase of Vibrio cholerae. Removal of sialic acid from the proteins in a preparation of diphtheria antitoxin did not alter the inhibitory activity of the antitoxin against diphtheria sialidase. The enzyme operated optimally at pH 5.5 and did not require calcium ions for activity. The substrate specificity of diphtheria sialidase appears to be the same as that of other previously described sialidases.

Corynebacterium diphtheriae↗

Evidence of multiple taxa within commercially available reference strains of Corynebacterium xerosis.

Attempts to identify coryneform isolates resembling Corynebacterium xerosis can lead clinical microbiologists to identification schemes with conflicting descriptions which result in confusing C. xerosis with Corynebacterium striatum. For the present study we purchased all available American Type Culture Collection and National Collection of Type Cultures reference cultures of C. xerosis (n = 10) and C. striatum (n = 4) and analyzed them as follows: (i) analysis of biochemical reactions in conventional tests and in the Rapid CORYNE system, (ii) whole-cell fatty acid analysis by using the gas-liquid chromatography research software of Microbial ID, Inc., and (iii) analysis of DNA homology in dot blot hybridizations. Three C. xerosis strains were indistinguishable from the C. striatum strains in whole-cell fatty acid analyses and DNA hybridizations and shared very similar biochemical reactions. The remaining seven strains of C. xerosis clustered into five groups on the basis of fatty acid patterns, DNA hybridizations, and biochemical tests. No reference strain of C. striatum fit the species description in Bergey's Manual of Systematic Bacteriology. The type strains of both C. striatum and C. xerosis fit their respective descriptions by the Centers for Disease Control and Prevention. This study suggests that the 10 commercially available reference strains of C. xerosis represent six different taxa which should be assigned to new species.

Bacterial Typing Techniques↗

Prevalence of Corynebacterium urealyticum in urine specimens collected at a university-affiliated medical center.

Corynebacterium urealyticum (formerly Corynebacterium group D2) has been implicated as a cause of alkaline-encrusted cystitis and urinary tract struvite calculi. Despite preselecting urine specimens with neutral and alkaline pHs and using prolonged incubation on a selective medium, isolation of this organism was rarely observed in a population of hospitalized patients. We do not recommend routine cultures for this organism unless the urine is alkaline and struvite crystals, leukocytes, and erythrocytes are present.

Academic Medical Centers↗

Prosthetic valve endocarditis caused by Corynebacterium afermentans subsp. lipophilum (CDC coryneform group ANF-1).

Corynebacteria are important causes of endocarditis in individuals with valvular prostheses. We report the first published case of prosthetic valve endocarditis caused by the newly defined species Corynebacterium afermentans subsp. lipophilum (former CDC coryneform group ANF-1). The isolate was recovered from a perivalvular abscess specimen and 5 of 15 Bactec blood cultures after 7 to 15 days of incubation. The isolation, identification, and susceptibility testing of Corynebacterium species are discussed.

Aged↗

Endocarditis of native aortic and mitral valves due to Corynebacterium accolens: report of a case and application of phenotypic and genotypic techniques for identification.

Endocarditis of native aortic and mitral valves due to an organism identified as Corynebacterium accolens developed in a 73-year-old patient without predisposing factors. The organism was identified as C. accolens by biochemical identification, amplified rRNA gene restriction analysis, and DNA-DNA hybridization. This is the first case of C. accolens endocarditis reported, adding to the increasing number of Corynebacterium-related cases of endocarditis.

Aged↗