Corynebacterium Research Articles

Dermabacter jinjuensis sp. nov., a novel species of the genus Dermabacter isolated from a clinical specimen.

A Gram-stain-positive, catalase-positive, facultatively anaerobic, non-motile, coryneform bacterium, designated strain 32T, was isolated from a closed pus sample from a patient having finger necrosis in Korea. Strain 32T was considered as representing a novel species according to its initial identification by matrix-assisted laser desorption/ionization-time-of-flight MS. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 32T belonged to the genus Dermabacter and was closely related to Dermabacter hominis DSM 7083T (=ATCC 49369T) (98.34 % similarity). Optimal growth was observed at 30-40 °C and pH 7. Growth occurred in the presence of 0-6 % (w/v) NaCl. Menaquinones MK-8, MK-7 and MK-9 were the major respiratory quinones. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, glycolipid and two unknown lipids. The major cellular fatty acids were anteiso-C17 : 0, anteiso-C15 : 0, iso-C16 : 0 and iso-C15 : 0. The DNA G+C content of strain 32T was 62.58 mol%, and the mean level of DNA-DNA relatedness between strain 32T and D. hominis ATCC 49369T was 49±1.6 %. Based on the phenotypic and genotypic characteristics, strain 32T is confirmed to represent a novel species of the genus Dermabacter, for which the name Dermabacter jinjuensis sp. nov. is proposed. The type strain is 32T (=NCCP 16133T=DSM 101003T).

Corynebacterium diphtheriae : an emerging cause of Chronic Suppurative Otitis Media

Corynebacterium diphtheriae : an emerging cause of Chronic Suppurative Otitis Media

Clinical and epidemiological features of coryneform skin infections at a tertiary hospital.

Background:Skin infections caused by coryneform bacteria are common dermatological conditions. However, to the best of our knowledge, no studies are available on the clinical characteristics and epidemiological features of this group of disorders as one entity from India and abroad.Aims:To study the clinical and epidemiological features of coryneform skin infectionsMethods:A total of 75 patients presenting with clinically distinctive lesions of pitted keratolysis, erythrasma and trichobacteriosis to our hospital were included in the study. Cases were interviewed with particular emphasis on epidemiological features and the various clinical findings were recorded. Investigations like Gram's stain, Wood's light examination, 10% KOH scrapings, were done in selected cases to ascertain the diagnosis.Results:Pitted keratolysis was more common in the age group of 31-40 years (40%) with a male preponderance (76.7%), most commonly affecting pressure bearing areas of the soles with malodour (86.7%) and frequent contact with water (58.3%) constituting the most important presenting symptom and provocating factor respectively. Erythrasma affected both male and female patients equally and was more commonly detected in patients with a BMI > 23kg/m2 (62.5%) and in diabetics (50%). All patients with trichobacteriosis presented with yellow coloured concretions in the axillae. Bromhidrosis (71.4%) and failure to regularly use an axillary deodorant (71.4%) were the most common presenting symptom and predisposing factor respectively.Conclusion:Coryneform skin infections are common dermatological conditions, though epidemiological data are fragmentary. Hyperhidrosis is a common predisposing factor to all three coryneform skin infections. Asymmetrical distribution of pits has been reported in our study. Diabetic status needs to be evaluated in all patients with erythrasma. Woods lamp examination forms an indispensible tool to diagnose erythrasma and trichobacteriosis.

Мутации в гене fusA, кодирующем фактор элонгации G у коринеформных бактерий, приводят к повышению продукции лизина

Мутации в гене fusA, кодирующем фактор элонгации G у коринеформных бактерий, приводят к повышению продукции лизина

Glutamate Fermentation-2: Mechanism of L-Glutamate Overproduction in Corynebacterium glutamicum.

The nonpathogenic coryneform bacterium, Corynebacterium glutamicum, was isolated as an L-glutamate-overproducing microorganism by Japanese researchers and is currently utilized in various amino acid fermentation processes. L-Glutamate production by C. glutamicum is induced by limitation of biotin and addition of fatty acid ester surfactants and β-lactam antibiotics. These treatments affect the cell surface structures of C. glutamicum. After the discovery of C. glutamicum, many researchers have investigated the underlying mechanism of L-glutamate overproduction with respect to the cell surface structures of this organism. Furthermore, metabolic regulation during L-glutamate overproduction by C. glutamicum, particularly, the relationship between central carbon metabolism and L-glutamate biosynthesis, has been investigated. Recently, the role of a mechanosensitive channel protein in L-glutamate overproduction has been reported. In this chapter, mechanisms of L-glutamate overproduction by C. glutamicum have been reviewed.

Mutations in the fusA Gene that Encodes Elongation Factor G in Coryneform Bacterium Lead to Increased Lysine Production

Mutations in the fusA Gene that Encodes Elongation Factor G in Coryneform Bacterium Lead to Increased Lysine Production

Clinical observations of acute-onset endophthalmitis after clear corneal phacoemulsification

To evaluate the incidence of acute-onset endophthalmitis after clear corneal phacoemulsification and to report its clinical features, microbiology, and therapeutic efficacy. It was a retrospective case series study. Medical records were reviewed for all patients diagnosed with acuteonset postoperative endophthalmitis from 2006 through 2013 associated with cataract surgery at Shandong Eye Institute of China. The 8-year frequency of acute-onset endophthalmitis after clear corneal phacoemulsification was 0.13%. The mean time between cataract extraction and endophthalmitis onset was 6 days (median, range 1 to 37 days). Endophthalmitis onset occurred within 7 days in 57.1%. The incidence was significantly higher in summer (0.25%) than in other seasons seasons (F=8.61, P=0.05). The incidence in diabetes was 0.06% , and in non-diabetic patients was 0.16% (F=1.51, P=0.23). There were no significantly difference (F=0.003, P=0.422, ) in the endophthalmitis rates between those with capsular rupture (0.24%)and those without (0.13%). Three of the 21 cases (14.3%) were cured by antibiotic agents only. Antibiotic irrigation of the capsular bag was taken in 8 patients (38.1%). Six patients (28.6%) had both antibiotic irrigation of the capsular bag and intravitreal injection of the antibiotics and the other 4 patients (19.0%) were cured by vitreous surgery. Cultures were positive in 33.3% of cases with aqueous humor samples and in 16.7% of cases with vitreous biopsy. The culture isolates showed Staphylococcus species in 2 eyes, while Pseudomonas paucimobilis, Corynebacterium xerose, Neisseria mucosa and Enterococcus faecalis in 1 eye respectively. Sixteen patients (76.2%) achieved a final visual acuity of 20/40 or better. Five (23.8%) had worse than 20/40 to better than 20/200. No eyes were eviscerated. Early recognition and appropriate treatment are the most important factors in the successful management of endophthalmitis.

Caenorhabditis elegans star formation and negative chemotaxis induced by infection with corynebacteria.

Caenorhabditis elegans is one of the major model systems in biology based on advantageous properties such as short life span, transparency, genetic tractability and ease of culture using an Escherichia coli diet. In its natural habitat, compost and rotting plant material, this nematode lives on bacteria. However, C. elegans is a predator of bacteria, but can also be infected by nematopathogenic coryneform bacteria such Microbacterium and Leucobacter species, which display intriguing and diverse modes of pathogenicity. Depending on the nematode pathogen, aggregates of worms, termed worm-stars, can be formed, or severe rectal swelling, so-called Dar formation, can be induced. Using the human and animal pathogens Corynebacterium diphtheriae and Corynebacterium ulcerans as well as the non-pathogenic species Corynebacterium glutamicum, we show that these coryneform bacteria can also induce star formation slowly in worms, as well as a severe tail-swelling phenotype. While C. glutamicum had a significant, but minor influence on survival of C. elegans, nematodes were killed after infection with C. diphtheriae and C. ulcerans. The two pathogenic species were avoided by the nematodes and induced aversive learning in C. elegans.

Cystic Neutrophilic Granulomatous Mastitis: Further Characterization of a Distinctive Histopathologic Entity Not Always Demonstrably Attributable to Corynebacterium Infection.

Granulomatous lobular mastitis (GLM) is an uncommon condition that typically occurs in parous, reproductive-aged women and can simulate malignancy on the basis of clinical and imaging features. A distinctive histologic pattern termed cystic neutrophilic granulomatous mastitis (CNGM) is seen in some cases of GLM and has been associated with Corynebacterium infection. We sought to further characterize the clinical, imaging, and histopathologic features of CNGM by studying 12 cases and attempted to establish the relationship of this disease with Corynebacterium infection. Patients were women ranging in age from 25 to 49 years (median: 34 y), and all presented with a palpable mass that was painful in half of the cases. In 2 of 9 cases, imaging was highly suspicious for malignancy (BI-RADS 5). CNGM was characterized by lobulocentric granulomas with mixed inflammation and clear vacuoles lined by neutrophils within granulomas. Gram-positive bacilli were identified in 5/12 cases. In 4 patients, the disease process worsened after the diagnostic core biopsy, with the development of a draining sinus in 2 cases. No growth of bacteria was seen in any microbial cultures. No bacterial DNA was identified by 16S rDNA polymerase chain reaction for 1 case that showed gram-positive bacilli on histology. Patients were treated with variable combinations of surgery, antibiotics, and steroids. The time to significant resolution of symptoms ranged from 2 weeks to 6 months. Similar to other forms of GLM, CNGM can mimic malignancy clinically and on imaging. When encountered in a needle core biopsy sample, recognition of the characteristic histologic pattern and its possible association with Corynebacterium infection can help guide treatment.

Multi-Etiological Nature of Tuberculosis-Like Lesions in Condemned Pigs at the Slaughterhouse.

Tuberculosis-like lesions (TBL) in pigs have been associated with microorganisms other than mycobacteria. In this work a histopathological and microbiological evaluation of TBL in pigs is shown. A total of 352 samples belonging to 171 pigs totally condemned at slaughterhouse due to generalized TBL were sampled and selected for analysis. Pyogranulomatous (56.2%) and granulomatous lesions (20.2%) were observed in all analysed organs. Most of the granulomas observed in both lymph nodes and lungs belonged to more advanced stages of development (stages III and IV) whereas in the liver and the spleen most of lesions belonged to intermediate stages (stages II and III). Different microorganisms were simultaneously detected from TBL in the 42.7% of the animals. Mycobacterium tuberculosis complex (MTC) (38%), coryneform bacteria (40.3%) and streptococci (28.1%) were the main groups of microorganisms detected after bacteriological analysis, with Trueperella pyogenes and Streptococcus suis as the most frequently isolated species. Mycobacteria belonging to MTC were the most frequently detected pathogens in granulomatous and pyogranulomatous lesions in submandibular lymph nodes (32.7%) and coryneform bacteria were the microorganisms more frequently isolated from lungs (25.9%) and spleen samples (37.2%). These results may provide new insights into the pathogenesis and diagnosis of this pathology. The importance of coryneform bacteria and streptococci in such processes must be evaluated in future studies.

Importance of Coryneform Bacteria in Infective Endocarditis.

Coryneform bacteria have been defined as non-sporing Gram-positive rods with an irregular outline[...]

Bacterial isolates and in vitro antimicrobial susceptibility in blepharitis

Background Blepharitis is an induce factor for multiple ocular surface diseases. Research showed that bacteria play an important role in the pathogenesis of blepharitis. To make sure the pathogenic bacteria and effective antimicrobial agents are of clinical significance for the prevention and treatment of blepharitis. Objective The purpose of this study was to investigate the bacterial isolates of conjunctival sac secretion and meibomian secretion in the patients with blepharitis and study their in vitro antimicrobial susceptibility. Methods Forty-five patients with anterior blepharitis and 45 cases with posterior blepharitis were included in Beijing Chaoyang Hospital from December 2006 to December 2012, and 45 patients for laser in situ keratomileusis were enrolled in the same period as control group. The secretions of the conjunctival sac and meibomian were collected with sterile cotton swab, and bacterial isolates were cultured in bouillon culture-medium. The number of eyes with different bacteria was examined and calculated. Then the bacteria were switched to blood agar plates, and antimicrobial susceptibility test to erythromycin, gentamicin, tobramycin, rifampin, levofloxacin were performed by Mueller Hinton (M-H) medium paper method. Results The total germiculture positive rates were 81.1%, 76.1% and 65.0% in the anterior blepharitis group, posterior blepharitis group and the control group, showing a significant difference among them (χ2=12.80, P=0.00). The germiculture positive rates in meibomian secretion were 84.4% and 78.8% in the anterior blepharitis group and the posterior blepharitis group, which were significantly higher than 67.8% in the control group (χ2=7.30, P=0.03). There was no statistically significant difference in the germiculture positive rate of conjunctival sac section among the three groups (77.8%, 73.3% and 62.2%) (χ2=5.60, P=0.06). The main bacteria in conjunctival sac secretion and meibomian secretion were staphylococcus epidermidis, staphylococcus aureus and corynebacterium in all the subjects, but streptococcus pneumoniae and gram-negative bacillus were not detected in the control group. Staphylococcus showed the highest susceptibility to gentamicin, tobramycin and rifampicin, with the sensitive rate >70%. Corynebacterium was susceptible to various drugs. Streptococcus pneumoniae had susceptibility to erythromycin and tobramycin. However, Gram-negative bacillus was not susceptible to all the drugs above. Conclusions Bacteria participate in the pathogenesis of blepharitis, but the germiculture positive rate, bacterial species and drug susceptibility of bacteria are obviously different between patients with blepharitis and normal population. Reasonable application of antimicrobial agents is important to blepharitis. Key words: Blepharitis; Germiculture; Antimicrobial susceptibility test

Somethings's in the Air

First, some gossip. During a meeting last year, I heard a story from the director of a middle-ranking medical microbiology laboratory in southern Europe. Staff there had been perplexed by the unexpected, unexplained detection of a coryneform bacterium during routine screening of swabs from a nearby hospital. On five separate occasions, the organism had appeared on MacConkey agar and other cultures, and was at first difficult to identify. Only after the apparent contaminant was sent for further investigation to a reference laboratory elsewhere was part of the mystery solved. There, 16S rRNA gene sequencing showed the organism to be Brevibacterium otitidis.

Microbial Deterioration of Tomato Fruit ( Lycopersicon esculentum ) Sold in Three Popular Markets in Ilorin, Kwara State, Nigeria

The economic loss as a result of spoilage and proliferation of microorganisms on tomato fruits with the possible health risks were the justification for this study. One hundred and fifty tomato fruit samples in different stages of spoilage from three different markets in Ilorin, Kwara State, Nigeria were collected within five weeks and the effect of moisture content on each sample and resulting microflora examined. The pH of the samples ranged from 4.90 - 5.40, while the moisture content ranged from 89.10% - 90.70%. The bacteria counts ranged from 4.00 x 106 - 7.50 x 106 cfu/ml, while the fungal counts ranged from 1.60 x 106 - 3.50 x 106 cfu/ml. A total number of sixteen bacteria and eleven fungi including yeasts were associated with the samples. The bacterial isolates included Aeromonas veronii , Bacillus sp., Neisseria sp., Coryne bacterium renale, Pseudomonas fluorescens , Micrococcus varian s , Moraxella sp., Bacillus polymyxa, Aeromonas hydrophila , Pseudomonas sp., Bacillus megaterium , Corynebacterium ulcerans , Vibrio sp., Proteus mirabilis , Corynebacterium xerosis , and Bacillus brevis while the fungal isolates included Alternaria sp., Botrytis sp., Candida albicans , Candida guilliermondii , Candidatropicalis , Chrysosporium tropicum , Curvularia sp., Doratomyces microsporus , Geotrichum candidum , Saccharomyces cerevisiae , and Rhizopus stolonifer . The high moisture content of the tomato samples provides an enabling environment for proliferation of the microbial load and hence its spoilage and potential to become health risk to human beings.

Preliminary analyses on bacterial diversity and resistance in infection-related skin disorders

To explore the bacterial diversity and resistance in infection-related skin disorders. The samples of blood, pyogenic fluid, exudate and skin dander were collected from 54 outpatients of chronic and recurrent skin disease and cultured for positive pathogens in the dermatological department of Peking University Third hospital from March 2010 to May 2011. Also their drug susceptibilities were examined. Among 63 bacterial strains of 22 species in 12 genus, the pathogens were Staphylococcus epidermidis, Staphylococcus aureus, Micrococcus luteus, group A Streptococcus pyogenes, Staphylococcus agalactiae, Corynebacterium sp., Bacillus subtilis, Bacillus cereus, Acinetobacter baumanii, A. lwoffii, Pseudomonas aeruginosa, Enterobacter cloacae, Rhizobium radiobacter, Sphingomonas paucimobilis, Enterococcus faecalis, Neisseria sicca and Neisseria gonorrhoeae. The percentage of methicillin-resistant coagulase negative staphylococci (MRCNS) was 46.4% (13/28) while the resistant rates of Styphylococci to ampicillin, penicillin, azithromycin, cefoxitin, clindamycin and SMZ-TMP were 88.6% (31/35), 88.6% (31/35), 68.6% (24/35), 37.1 (13/35), 28.6(10/35) and 26.5 (9/34) respectively. Gram negative bacilli were sensitive to ampicillin, amikacin sulfate, ceftazidime. There are a wide range of pathogenic bacterial species among refractory infection of outpatients. And drug resistance is among the reasons for refractory infections.

Status of subclinical mastitis and associated risk factors in Indian water buffalo in Doaba region of Punjab, India.

Abstract Sub clinical mastitis in buffalo is considered as multi-factorial disease, which leads to huge economic losses by reducing the quality and quantity of the milk. It does not lead to any change in phenotypic expression, so diagnosed through various tests as California mastitis test, Somatic cell count, Electrical conductivity test etc. Although bacteria are considered to be the main causative agent for mastitis, beside this farm management practices are found to be associated with the disease. In the present study, the pathogens related to the occurrence of the disease were examined via bacteriological culture of milk sample of the animal. Animal wise prevalence of sub clinical mastitis was found to be (20.4%), out of this 7.8%, 9.8%, 2.8% were found to be effected with latent mastitis, specific mastitis and nonspecific mastitis respectively .On the basis of individual quarter, the highest prevalence was in LH (33.9%), followed by RH (24%) and RF (22.4%) and the least prevalence in LF (14.5%). The microorganisms isolated from sub clinical mastitis constituted Staphylococci (39%), Streptococci (31%), Corynebacterium (25%) and E. coli .(5%).Farm management associated determinants (Type of feed, type of floor, education of the owner, feeding after milking, type of labor) were studied in association with sub clinical mastitis. Out of these education of the owner , type of labor and feeding after milking were found to be significantly associated with disease occurrence (p<0.05). While looking at the animal determinants in association with sub clinical mastitis in the present investigation buffaloes with higher parity showed more risk of developing sub clinical mastitis. So the present investigation helps to understand the various risk factors for the occurrence of sub clinical mastitis in water buffalo in Doaba region of Punjab.

Investigation of Evolutionary Events in Corynebacteriaceae Involving Prenyltransferases in Corynebacterium glutamicum

Terpenoids, a class of compounds with 30,000 unique structures, are known to include antitumor compounds, pigments, vitamins, antibiotics, and flavor molecules. Prenyltransferases are the primary enzyme responsible for assembling the carbon backbone of these compounds from five carbon isoprene units. Bioinformatic analysis has indicated that an evolutionary event has resulted in the acquisition of an additional prenyltransferase in Corynebacterium glutamicum (C. glutamicum) compared to the majority of the Corynebacteriaceae. This result suggests that C. glutamicum may produce a non‐essential terpenoid compound, or secondary metabolite. Sequencing has confirmed the successful cloning of the aforementioned genes. Present work includes expressing these genes in Escherichia coli, isolating the protein product, and assessing the function in vitro. This data will be used to expand our understanding of the evolutionary path of C. glutamicum compared to other members of the genus. Continuing work will shed light on the function of the third gene for C. glutamicum, and understanding the role of terpenoids in the family Corynebacteriaceae and greater Actinobacteria.

Cancer du sein traité par antibiotherapie ? Mastite granulomateuse à corynébactérie

Granulomatous mastitis is a rare disease, often associated with Corynebacterium infection. It raises the problem of diagnosis of breast tumor with a fast evolution and inflammatory character. We report two cases of granulomatous mastitis with Corynebacterium. It concerns the clinical and radiological description, followed by the therapeutic alternatives and future of the patients. The clinical presentation is variable. The treatment consists in a surgical procedure of resection. The medical treatment based of corticosteroids also proves efficient. The association between Corynebacterium presence and this pathology seems frequent and needs a specific bacteriological search.

Investigation and analysis of bacterial spectrum in conjunctival sac of elderly people of Kazak

Objective To analyze the bacterial spectrum in conjunctival sac of the elderly of Kazakh and its influential factors. Methods The 538 speciments of conjunctival sac secretion in the elderly of Kazak aged 40 to 93 years old were collected. The bacterial culture and identification of conjunctival sac secretion was performed. Results The bacterial culture were positive in 214 specimens, and the positive rate was 39.78%. The variety of pathogenic bacteria was mainly gram positive cocci (88.32%), and Staphylococcus epidermidis was the most common type(66.36%), followed by Micrococcus (9.81%), Staphylococcus saprophyticus (4.21%) and Corynebacterium (4.21%). Sex had no effect on conjunctival bacteria rate in the elderly Kazak, while age and place of residence had an effect on carrier rate. The carrier rate of conjunctival bacteria was significantly higher in people over 60 years old than that in people with age between 40 to 59 years old. The carrier rate of conjunctival bacteria in agricultural and pastoral areas was significantly higher than that in city area. Conclusion Gram positive cocci is the most common bacteria in conjunctival sac in elderly Kazak, especially staphylococcus epidermidis. The carriage status of conjunctival sac in Kazakh population is associated with the patient's age and residence place. Key words: Kazakh; Elderly; Sac, conjunctival; Spectrum, bacterial

Bio-aerosols concentrations in different wards of Khorramabad Hospital, Iran, 2013

Aims: This study was conducted to investigate the indoor and outdoor air quality at Ashayer Hospital in Khorramabad, Lorestan, Iran, from May-August 2013. Materials and Methods: Air samples were collected using the ZEFON pump (ZEFON factory, USA) based on manufacturer instructions. Bacteria were isolated via differential methods. Diagnosis of fungi was performed based on amount of fungal colonies growth, shapes, colors, pigments, and microscopic procedure. The effects of various environmental factors including temperature, humidity and outdoor bioaerosol levels were also investigated. Results: Staphylococcus spp. were the most predominant isolated bacteria from studied wards. Furthermore, other microorganisms including Streptococcus spp. Corynebacterium spp., and Micrococcus spp. were also isolated from the hospital air. Moreover, the most frequent fungus in indoor environments of hospital was Penicillium spp., while Aspergillusspp. and Alternaria spp. were the next frequent ones. In addition, the most frequent fungi in adjacent outdoors were Penicillium spp., Aspergillus spp., and Cladosporium spp., respectively. No significant difference was found between the mean concentrations of bioaerosols in inside and outside of hospital (P > 0.05). Conclusion: This study suggests that the bioaerosols level in the hospitals were relatively high. Thus, hospitals should enhance practice of good sanitation protocols and infection control measures.