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The genus Clavibacter (family Microbacteriaceae) includes gram‐positive actinobacterial species infecting diverse agricultural crops such as alfalfa, maize, pepper, potato, tomato and wheat. Clavibacter tessellarius, causing bacterial mosaic of wheat, was reported for the first time in 1976 in Nebraska (United States). Since then, the pathogen was thought to be restricted to North America (Canada and the United States). While bacterial strains suspected to be C. tessellarius have occasionally been isolated from wheat samples outside North America, occurrence of the pathogen in the Old World has not yet been confirmed by the plant protection authorities. In spring 2020 (January to May) dozens of wheat fields with young plants showing leaf chlorosis and mild mosaic symptoms were surveyed and sampled in southern Iran. Among 192 surveyed wheat fields, gram‐positive, orange‐pigmented actinobacterial strains were isolated from samples of 53 fields. Altogether, 61 bacterial strains were identified as C. tessellarius based on the phenotypic features, PCR‐based molecular tests and pathogenicity assays. Multilocus sequence analysis of five housekeeping genes (atpD, dnaK, gyrB, ppk and rpoB) using 10 representative strains from diverse geographic areas in southern Iran confirmed the phylogenetic status of the strains within C. tessellarius. Our data indicate that the bacterial mosaic pathogen occurs in four southern Iranian provinces including Bushehr, Fars, Kerman and Khuzestan. Thus, occurrence of C. tessellarius outside North America is confirmed. Potential risks associated with the emergence of the pathogen in the Old World, and the need for strict quarantine measures in the area, is further discussed. [ABSTRACT FROM AUTHOR]

Goss's bacterial wilt and leaf blight of maize (Zea mays) caused by the gram‐positive coryneform bacterium Clavibacter nebraskensis is an economically important disease in North America. C. nebraskensis is included within the high‐risk list of quarantine pathogens by several plant protection organizations (EPPO code: CORBMI), hence it is under strict quarantine control around the world. The causal agent was reported for the first time on maize in Nebraska (USA) in 1969. After an outbreak during the 1970s, prevalence of the disease decreased in the 1980s to the early 2000s, before the disease resurged causing a serious threat to maize production in North America. The re‐emergence of Goss's wilt in the corn belt of the United States led to several novel achievements in understanding the pathogen biology and disease control. In this review, we provide an updated overview of the pathogen taxonomy, biology, and epidemiology as well as management strategies of Goss's wilt disease. First, a taxonomic history of the pathogen is provided followed by symptomology and host range, genetic diversity, and pathogenicity mechanisms of the bacterium. Then, utility of high‐throughput molecular approaches in the precise detection and identification of the pathogen and the management strategies of the disease are explained. Finally, we highlight the role of integrated pest management strategies to combat the risk of Goss's wilt in the 21st century maize industry. Disease symptoms: Large (2–15 cm) tan to grey elongated oval lesions with wavy, irregular water‐soaked margins on the leaves. The lesions often start at the leaf tip or are associated with wounding caused by hail or wind damage. Small (1 mm in diameter), dark, discontinuous water‐soaked spots, known as "freckles", can be observed in the periphery of lesions. When backlit, the freckles appear translucent. Early infection (prior to growth stage V6) may become systemic and cause seedlings to wilt, wither, and die. Coalescence of lesions results in leaf blighting. Host range: Maize (Zea mays) is the only economic host of the pathogen. A number of Poaceae species are reported to act as secondary hosts for C. nebraskensis. Taxonomic status of the pathogen: Class: Actinobacteria; Order: Micrococcales; Family: Microbacteriaceae; Genus: Clavibacter; Species: Clavibacter nebraskensis. Synonyms Corynebacterium nebraskense (Schuster, 1970) Vidaver & Mandel 1974; Corynebacterium michiganense pv. nebraskense (Vidaver & Mandel 1974) Dye & Kemp 1977; Corynebacterium michiganense subsp. nebraskense (Vidaver & Mandel 1974) Carlson & Vidaver 1982; Clavibacter michiganense subsp. nebraskense (Vidaver & Mandel 1974) Davis et al. 1984; Clavibacter michiganensis subsp. nebraskensis (Vidaver & Mandel 1974) Davis et al. 1984. Type materials: ATCC 27794T; CFBP 2405T; ICMP 3298T; LMG 3700T; NCPPB 2581T. Microbiological properties: Cells are gram‐positive, orange‐pigmented, pleomorphic club‐ or rod‐shaped, nonspore‐forming, nonmotile, and without flagella, approximately 0.5 × 1–2.0 μm. Distribution: The pathogen is restricted to Canada and the United States. Phytosanitary categorization: EPPO code CORBNE. [ABSTRACT FROM AUTHOR]

Background: Bacterial ring rot of potato (Solanum tuberosum) caused by the gram‐positive coryneform bacterium Clavibacter sepedonicus is an important quarantine disease threatening the potato industry around the globe. Since its original description in 1906 in Germany, management of ring rot has been a major problem due to the seedborne nature (via seed tubers not true seeds) of the pathogen allowing the bacterium to be transmitted long distances via infected tubers. Disease symptoms: On growing potato plants: interveinal chlorosis on leaflets leading to necrotic areas and systemic wilt. On infected tubers: vascular tissues become yellowish brown with a cheesy texture due to bacterial colonization and decay. Host range: Potato is the main host of the pathogen, but natural infection also occurs on eggplant, tomato, and sugar beet. Taxonomic status of the pathogen: Class: Actinobacteria; Order: Actinomycetales; Family: Microbacteriaceae; Genus: Clavibacter; Species: Clavibacter sepedonicus (Spieckermann and Kotthoff 1914) Li et al. 2018. Synonyms (nonpreferred scientific names): Aplanobacter sepedonicus; Bacterium sepedonicum; Corynebacterium sepedonicum; Corynebacterium michiganense pv. sepedonicum; Clavibacter michiganensis subsp. sepedonicus. Microbiological properties: Gram‐positive, club‐shaped cells with creamy to yellowish‐cream colonies for which the optimal growth temperature is 20–23°C. Distribution: Asia (China, Japan, Kazakhstan, Nepal, North Korea, Pakistan, South Korea, Uzbekistan, the Asian part of Russia), Europe (Belarus, Bulgaria, Czech Republic, Estonia, Finland, Georgia, Germany, Greece, Hungary, Latvia, Lithuania, Norway, Poland, Romania, European part of Russia, Slovakia, Spain, Sweden, Turkey, Ukraine), and North America (Canada, Mexico, USA). Phytosanitary categorization: CORBSE: EPPO A2 list no. 51. EU; Annex designation I/A2. [ABSTRACT FROM AUTHOR]

Curtobacterium flaccumfaciens (Microbacteriaceae), a plant-pathogenic coryneform species includes five pathovars with valid names and a number of proposed – but unvalidated – new members. In this study, phenotypic features and DNA similarity indexes were investigated among all C. flaccumfaciens members. Results showed that the C. flaccumfaciens pv. poinsettiae strains causing bacterial canker of Euphorbia pulcherrima in the USA as well as the orange-/red-pigmented strains of C. flaccumfaciens pv. flaccumfaciens pathogenic on dry beans in Iran are too distinct from each other and from the type strain of the species to be considered members of C. flaccumfaciens. Hence, the latter two groups were elevated at the species level as C. poinsettiae sp. nov. (ATCC 9682T = CFBP 2403T = ICMP 2566T = LMG 3715T = NCPPB 854T as type strain), and C. aurantiacum sp. nov. (50RT = CFBP 8819T = ICMP 22071T as type strain). Within the emended species C. flaccumfaciens comb. nov., yellow-pigmented strains causing bacterial wilt of dry beans and those causing bacterial canker of Euphorbia pulcherrima in Europe were retained as C. flaccumfaciens pv. flaccumfaciens and C. flaccumfaciens pv. poinsettiae, respectively; while taxonomic position of the sugar beet pathogen C. flaccumfaciens pv. beticola ATCC BAA144PT was confirmed. The newly described onion pathogen C. allii was also reclassified as C. flaccumfaciens pv. allii with the pathotype strain LMG 32517PT. Furthermore, C. flaccumfaciens pv. basellae causing bacterial leaf spot of malabar spinach (Basella rubra) was transferred to C. citreum pv. basellae with ATCC BAA143PT as pathotype. [ABSTRACT FROM AUTHOR]

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The species composition, antilysozyme activity and antibiotic resistance of coryneform bacteria, isolated from the reproductive tract of women with microecological disturbances, were studied. Sixty six women without microecological disturbances and 102 female patients with microecological disturbances in the reproductive tract were examined. The study showed that Corynebacterium minutissimum, C.amycolatum, C.group JK, C.bovis and C.pseudodiphtheriticum prevailed in the healthy women. In the patients with microecological disturbances in the reproductive tract C.vitarumen, C.matruchotii, C.striatum, C.renale and C.urealyticum were detected in addition to the above species. The average antilysozyme activity of the coryneform bacteria isolated from the healthy women was 1.32+0.47. In the patients with microecological disturbances in the reproductive tract it was 1.84+0.38. The in vitro susceptibility of the coryneform bacteria to antimicrobial agents was determined. High prevalence of resistance to beta-lactams (oxacillin and penicillin), erythromycin and co-trimoxazole was detected. Thus, the species variety and the antilysozyme activity of the coryneform bacteria in the reproductive tract of the women with microecological disturbances were found to be higher. The high prevalence of resistance to oxacillin, penicillin, erythromycin and co-trimoxazole in the coryneform bacteria isolated from the patients with the microecological disturbances did not differ from that in the healthy women.

Monomicrobial and polymicrobial infections may occur on the cornea, conjunctiva and the eyelid of cats. Corynebacterium species are categorized as nonpathogenic bacteria that are regularly detected in the conjunctiva of healthy cats. It has been reported that Corynebacterium species have been shown to be potentially harmful in a variety of tissues including ocular tissues, skin, and mucous membranes. The purpose of the current study was to investigate the presence of Corynebacterium spp. on the ocular surface and its antimicrobial sensitivity and susceptibility pattern. We investigated Corynebacterium species on the ocular surface and reviewed various species of Corynebacterium in terms of their antimicrobial susceptibility and the underlying molecular resistance mechanisms. The risk for Corynebacterium-related ocular infections in cats with low immunity, such as poor nutrition, corneal epithelial damage due to trauma, corneal perforation, lagophthalmos, chronic incurable glaucoma, long-lasting corneal sequestrum, and long-term use of topical steroids have been identified. 64 cats (78 eyes) of different ages and both sexes with various ocular disorders were swabbed. Corynebacterium spp. represented 34.6 % (n=27) of the collected sample and found to be susceptible to common antibiotics. Therefore, the use of antimicrobials for the treatment of ocular infections caused by Corynebacterium species should be a rational and sensible strategy along with provision of immunostimulants. [ABSTRACT FROM AUTHOR]

Bacterial wilt of dry beans (family Fabaceae) caused by the actino-bacterial agent Curtobacterium flaccumfaciens pv. flaccumfaciens is one of the most important diseases threatening edible legume production around the globe. Despite the economic losses due to the bacterial wilt disease, the pathogen has not so far been investigated for its genomic features, pathogenicity determinants, and virulence strategies. Here we present the first complete genome sequence of a highly virulent bacteriocin-producing C. flaccumfaciens pv. flaccumfaciens strain P990. The bacterium has a circular chromosome consisting of 3,736 kbp with the G+C% content of 71.0%. Furthermore, a 147-kbp circular plasmid (pCffl) with 66.1% G+C% content as well as two circular plasmid-like DNAs with sizes of 25 and 22 kbp were detected within the genomic contents of C. flaccumfaciens pv. flaccumfaciens. Phylogenetic analyses revealed that only a few number of Curtobacterium sp. strains deposited in the public databases could be classified within the species C. flaccumfaciens. Comparative genomics of C. flaccumfaciens pv. flaccumfaciens using the genome sequences of actinobacterial plant pathogens revealed the presence of a set of unique low G+C% content genomic islands in the C. flaccumfaciens pv. flaccumfaciens genome. Homologs of pathogenicity-determinant loci capable of producing 1,4-beta-xylanase (xysA), pectate lyase (pelAl and pelA2), serine protease (chpC, chpG, and pat-1), and sortase (srtA) were detected in C. flaccumfaciens pv. flaccumfaciens genome. The genomic data presented here extend our understanding of the C. flaccumfaciens pv. flaccumfaciens genomic features and pave the ways of research on functional and interaction genetics to combat the risk of bacterial wilt disease in the 21st century's dry bean industry. [ABSTRACT FROM AUTHOR]

Bacterial wilt and tan spot of dry beans (family Fabaceae), caused by Curtobacterium flaccumfaciens pv. flaccumfaciens, is an important emerging disease threatening the edible legume industry around the globe. The management of bacterial wilt has been a major problem since its original description in 1922. This is in part due to the seedborne nature of the pathogen allowing the bacterium to be transmitted long distances via infected seeds, as well as a lack of detailed molecular information concerning the pathogenicity repertoires and virulence determinates of the pathogen. Identification can also be difficult owing to the presence of five different colony colour variants (i.e., yellow, orange, pink, purple, and red) on culture media. In this review, we provide an overview of the aetiology, epidemiology, and management strategies of bacterial wilt disease. First, a comprehensive and comparative symptomology of the disease on different dry bean species is described. Then, the taxonomic history of the causal agent and utility of high‐throughput sequencing‐based approaches in the precise characterization of the pathogen is explained. Furthermore, we provide an updated outline on the global distribution of the pathogen, highlighting expansion of the causal agent into the areas with no history of the disease until the beginning of the current century. Finally, because there are limited options for use of conventional pesticides against the pathogen, we highlight the use of integrated pest management strategies, for example quarantine inspections, resistant cultivars, and crop sanitation, to combat the risk of bacterial wilt disease in the dry bean industry. Disease symptoms: Interveinal chlorosis on leaflets leading to necrotic areas and systemic wilt. Seed discolouration to yellow, orange, pink, or purple is seen in white‐seeded cultivars. Host range: Causes bacterial wilt and tan spot disease on edible dry beans in the Fabaceae family, including common bean (Phaseolus vulgaris), cowpea (Vigna unguiculata), mungbean (Vigna radiata), soybean (Glycine max), as well as a number of weed species. Taxonomic status of the pathogen: Bacteria; phylum Actinobacteria; order Actinomycetales; suborder: Micrococcineae; family Microbacteriaceae; genus Curtobacterium; species Curtobacterium flaccumfaciens. Synonyms: Corynebacterium flaccumfaciens subsp. flaccumfaciens; Corynebacterium flaccumfaciens pv. flaccumfaciens, Corynebacterium flaccumfaciens, Phytomonas flaccumfaciens, Bacterium flaccumfaciens. Microbiological properties: Multicoloured (yellow, orange, pink, purple, and red), gram‐positive, aerobic, curved rod, nonspore‐forming, polar flagellated, motile cells. Distribution: Widespread in America (Brazil, Canada, and the USA), Australia, and Iran. Restricted occurrence in Africa and Europe. Phytosanitary categorization: EPPO A2 list no. 48, EU Annex II⁄B. [ABSTRACT FROM AUTHOR]

Granulomatous lobular mastitis is a rare disease whose origin is still unknown and shows an increase in its frequency. Morphological, microbiological, and molecular biology studies have linked this disease to lipophilic and fastidious corynebacteria, suggesting its possible infectious etiology. This series describes and reviews in detail the distinctive morphological characteristics of the bacteria present in the granulomas of this disease, the usefulness of histochemical techniques for their identification, and our proposal for a tissue quantification score for the bacteria. The MacCallum-Goodpasture method of Gram's stain turned out to be the gold standard for examination, but we also highlight the efficiency of hematoxylin and eosin stain when it is exhaustively examined as well as the Grocott stain to evaluate the bacterial pleomorphism method, which is often underutilized. [ABSTRACT FROM AUTHOR]

In 2015, Gram-positive peach-coloured actinobacterial strains were isolated from symptomless tomato phyllosphere in Iran. Biochemical and physiological characteristics, as well as 16S rRNA phylogeny showed that the strains belong to Clavibacter sp., while they were non-pathogenic on the host of isolation, and morphologically distinct from the tomato pathogen C. michiganensis and other plant-associated bacteria. Multilocus sequence analysis of five housekeeping genes showed that the two peach-coloured strains CFBP 8615 T (Tom532 T ) and CFBP 8616 (Tom495) were phylogenetically distinct from all validly described Clavibacter species. Whole genome sequence-based indices, i.e. average nucleotide identity (orthoANI) and digital DNA-DNA hybridization (dDDH), showed that the two peach-colored strains share nearly 100 % orthoANI value with one another, while they differ from all validly described Clavibacter species with the orthoANI/dDDH values <93 % and <50 %, respectively. Thus, based on both phenotypic features and orthoANI/dDDH indices the peach-coloured strains could belong to a new species within Clavibacter . In this study, we provide a formal species description for the peach-coloured tomato-associated Clavibacter strains. Clavibacter lycopersici sp. nov. is proposed for the new species with Tom532 T = CFBP 8615 T = ICMP 22100 T as type strain.

Background: Starch-binding domains from carbohydrate binding module family 20 have been used as a tool for starch engineering. Previous studies showed that expression of starch binding domain fusion proteins in planta resulted in modified starch granule structures and physicochemical properties. However, although 13 carbohydrate binding module families have been reported to contain starch-binding domains, only starch-binding domains from carbohydrate binding module family 20 have been well studied and introduced into plants successfully. In this study, two fragments, the tandem CBM25 domain and the tandem CBM25 with multiple fibronectin type III (FN3) domains of the α-amylase enzyme from Microbacterium aurum, were expressed in the tubers of a wild type potato cultivar (cv. Kardal) and an amylose-free (amf) potato mutant. Results: The (CBM25)2 and FN3 protein were successfully accumulated in the starch granules of both Kardal and amf transformants. The accumulation of (CBM25)2 protein did not result in starch morphological alterations in Kardal but gave rise to rough starch granules in amf, while the FN3 resulted in morphological changes of starch granules (helical starch granules in Kardal and rough surface granules in amf) but only at a very low frequency. The starches of the different transformants did not show significant differences in starch size distribution, apparent amylose content, and physico-chemical properties in comparison to that of untransformed controls. Conclusion: These results suggest that the starch-binding domains from carbohydrate binding module family 25 can be used as a novel tool for targeting proteins to starch granules during starch biosynthesis without side-effects on starch morphology, composition and properties. [ABSTRACT FROM AUTHOR]

This study was conducted on Sudanese and Somalian imported camels at Al- Warraq abattoir, Giza (Egypt), during the period from September 2014 to November 2015. A total of 850 adult one-humped camels (Camelus dromedarius) were subjected to clinical and postmortem examinations. Caseous lymphadenitis lesions were detected in 88 (10.35%) animals. Superficial form (9.76%) was significantly more prevalent than the visceral form (0.58%). Incised lesions showed cheesy greenish-whitish pus, four lesions were congested without abscess formation. Coryneform bacteria were isolated as a pure culture in 11 (30.55%) cases. Targeting Corynebacterium pseudotuberculosis serotype 1, being a common cause of caseous lymphadenitis, two isolates were identified by pld gene-specific polymerase chain reaction. Other coryneforms were tested by the API Coryne system; three Cellulomonas spp./Microbacterium spp. and one Brevibacterium spp. were identified. The APIunidentified bacteria were subjected to the Vitek 2 system which identified two isolates as Corynebacterium jeikeium and Corynebacterium urealyticum. The Vitek 2 systemunidentified isolates were classified as unidentified coryneforms. Histopathological findings revealed suppuration, necrosis, hyperplastic lymphoid follicles and sinus histocytosis of the affected lymph nodes. In contrast to small ruminants, few studies are available on caseous lymphadenitis in camel and rare of them involve the visceral form. In conclusion, caseous lymphadenitis is prevalent in Sudanese and Somali imported camels in Egypt. In camels, the disease has variable natures and visceral lesions are uncommon. Coryneform bacteria other than Corynebacterium pseudotu1berculosis are associated with the disease in camels which necessitate multiple identification steps. [ABSTRACT FROM AUTHOR]

Various concentrations of biotin were tested in order to achieve fluent excretion of glutamic acid (glu) in a fermentation medium composed of a locally isolated Corynebacterium glutamicum strain. The behaviour of the strain was observed to vary with varying concentrations of biotin. Maximum values for specific growth rate (μ, h-1), cell mass yield (Yx/s, g/g), substrate consumption rate (QS, g/l h) and cell mass specific productivity (q-X, g/g h) were 0.34, 0.24, 2.92 and 1.43, respectively, given 10 μg biotin/100 ml under working conditions of a shake flask with temperature 30 °C, in 100 g glucose/l medium (pH 7.0). The kinetic parameters calculated for glutamate production under the above conditions were 4.94 g/l h, 4.4 g/g cells, 0.66 g/g, and 1.5 g/g h for Q-P, Y-P/X, Y-P/S, and q-P, respectively, and were comparatively higher than the respective values reported for some C. glutamicum strains growing on glucose in batch culture studies. Conversely, at biotin concentrations of 1.0, 2.5, 5.0, 15 μg/ ml, significantly less improvement in glu production was noticed, but at 10 μg/ml a nearly 2.2-fold increase in Q-P was observed, though the only statistically significant difference was in the QS value. [ABSTRACT FROM AUTHOR]

Background We examined the clinical characteristics and predictive factors for mortality in coryneform bacteria bloodstream infection in hematological patients. Methods We searched for hematological patients who had positive blood cultures for coryneform bacteria at our center between April 2007 and January 2016. Patients with definite bloodstream infections were included. We started species identification in April 2014. Results Twenty of twenty-eight cases with a positive blood culture for coryneform bacteria were regarded as definite infections. Sixteen and two patients were allogeneic and autologous hematopoietic stem cell transplantation (HSCT) recipients, respectively. Corynebacterium striatum was identified in all nine of the cases tested and one patient was co-infected with Corynebacterium amycolatum . None of the patients died directly due to coryneform bacteria infection. The survival rates at 30, 60 and 180 days were 100%, 73.7% and 51.3%, respectively. Causes of mortality included progression of the underlying disease (n = 6), other infections (n = 4) and HSCT complications (n = 2). Mixed infection (hazard ratio (HR) 5.47, 95% confidence interval (CI) 1.30–23.0), renal impairment (HR 6.31, 95% CI 1.06–37.4) and absence of a central venous (CV) catheter at the onset (HR 6.39, 95% CI 1.04–39.45) were identified as predictive factors for mortality. Conclusion Most of the coryneform bacteria bloodstream infections occurred in HSCT recipients. Contamination seemed to be less common when coryneform bacteria were detected in blood in hematological patients. Although coryneform bacteria bloodstream infection seemed to mostly be manageable, the prognosis was not desirable, particularly in patients with mixed infection, renal impairment and absence of a CV catheter. [ABSTRACT FROM AUTHOR]

Brevibacterium halotolerans is currently classified as a member of the Brevibacterium genus, a genus that groups together many bacterial species of similar morphology but diverse biochemical and physiological features. Here we suggest, based on multiple gene sequencing and microbial and biochemical characterization of two environmental isolates and one type strain (DSM8802), that the B. halotolerans DSM8802 (and probably the other deposited under this species name) should be re-classified into the Bacillus genus, and offered the name B. halotolerans comb. nov. [ABSTRACT FROM AUTHOR]

This paper demonstrated a biocementation technology for chromium slag by strain GM-1, a calcifying ureolytic bacterium identified as Microbacterium, based on microbially induced calcium carbonate. The characterization of Microbacterium sp. GM-1 was assessed to know the growth curve in different concentrations of Cr(VI). Microbacterium sp. GM-1 was tolerant to a concentration of 120 mg/L Cr(VI). Chromium waste forms were prepared using chromium, sand, soil and bacterial culture. There we had three quality ratios (8:2:1; 8:1:1; 8:2:0.5) of material (chromium, sand and soil, respectively). Bacterial and control chromium waste forms were analyzed by thermal gravimetric analyzer. All bacterial forms (8:2:1; 8:1:1; 8:2:0.5 J) showed sharp weight loss near the decomposition temperature of calcium carbonate between 600 and 700 °C. It indicated that the efficient bacterial strain GM-1 had induced calcium carbonate precipitate during bioremediation process. A five step Cr(VI) sequential extraction was performed to evaluate its distribution pattern in chromium waste forms. The percentage of Cr(VI) was found to significantly be decreased in the exchangeable fraction of chromium waste forms and subsequently, that was markedly increased in carbonated fraction after biocementation by GM-1. Further, compressive strength test and leaching test were carried out. The results showed that chromium waste forms after biocementation had higher compressive strength and lower leaching toxicity. Additionally, the samples made of 8:1:1 (m/m/m) chromium + sand + soil were found to develop the highest compressive strength and stand the lowest concentration of Cr(VI) released into the environment. [ABSTRACT FROM AUTHOR]

Background: Corynebacterium species and gram-positive coryneform-like bacteria (coryneforms) are increasingly reported causes of opportunistic infections in immunocompromised patients. Biochemical identification methods for these bacteria are often inaccurate. We evaluated matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for routine Corynebacterium and coryneform identification.Methods: A total of 286 Corynebacterium species and coryneforms recovered from patients were identified by MALDI-TOF MS analysis using the Bruker Microflex instrument, Biotyper software version 3.0, and database version 3.1.66 (Bruker Daltonics, Billerica, MA) following formic acid-based, direct on-plate extraction. The spectral cutoff scores used for interpretation were 2.0 or more for species-level identification and 1.7 or more for genus level. Scores lower than 1.7 were considered as no reliable identification. The results were compared with API Coryne (bioMérieux, Durham, NC) and sequencing of 16S ribosomal RNA genes.Results: Of the 231 Corynebacterium (19 species), 99.6% were correctly identified to the genus level and 88.7% to the species level. Of the 55 coryneforms (14 genera), 90.9% were correctly identified to the genus level and 67.3% to the species level. API Coryne was able to identify 89.2% of Corynebacterium species (species level) and 63.6% of coryneforms (genus level).Conclusions: Rapid on-plate testing yielded identification of more Corynebacterium species and related bacteria than biochemical methods. [ABSTRACT FROM AUTHOR]

The bacterium Microbacterium sp. GT35 was found to be capable of transforming Re and Rg, principal ginsenosides of the 20(S)-protopanaxatriol series, into minor glycosides 20(S)-Rg and 20(S)-Rh, respectively. The specificity of Microbacterium sp. GT35 differed from that of several other microorganisms by cleaving only the β-D-glucose on C-20 and not affecting the C-6 carbohydrates of 20(S)-protopanaxatriol. [ABSTRACT FROM AUTHOR]

Leifsonia xyli subsp . xyli (Lxx), causal organism of ratoon stunt ( RSD), does not produce any reliable internal or external symptoms on sugarcane. Its detection on a large scale is solely based on microscopic and serological methods. These methods require well-equipped laboratories, are time consuming and are not feasible for near-field detection of Lxx. In this study, we developed a loop-mediated isothermal amplification ( LAMP) assay for rapid and sensitive detection of Lxx without the use of sophisticated equipment. To the best of our knowledge, this is the first report on the detection of Lxx in 30 min via an isothermal amplification method at 65°C. A transposase gene, ISLxx5, was used to design a set of six primers specifically targeting eight genomic sequences. The xylem sap was used as template, thus circumventing the need to isolate pure genomic DNA. The positive reactions were visually detected through a colour change of hydroxynaphthol blue ( HNB) from violet to light blue, thus, eliminating the need for gel electrophoresis. The LAMP method was 10 times more sensitive than serological detection and as sensitive as immunofluorescence microscopy ( IFM). The simplicity and sensitivity of the ISLxx5 LAMP assay makes it suitable for near-field diagnosis of RSD. Significance and Impact of the Study Detection of Leifsonia xyli subsp. xyli ( Lxx) on a large scale is based on serological assays such as evaporative-binding enzyme-linked immunoassay ( EB- EIA). These methods are time consuming and require well-equipped laboratories. This study presents the development of a loop-mediated isothermal amplification ( LAMP) assay which allows detection of Lxx in 30 min at 65°C, using xylem sap as the template. The assay requires minimal laboratory equipment and could be used at near farm conditions, thus saving time and money required to transfer samples from remote areas to diagnostic laboratories. The LAMP method shows potential as an alternative detection method for RSD. [ABSTRACT FROM AUTHOR]

The endophytic bacterial communities of six Prunus avium L. genotypes differing in their growth patterns during in vitro propagation were identified by culture-dependent and culture-independent methods. Five morphologically distinct isolates from tissue culture material were identified by 16S rDNA sequence analysis. To detect and analyze the uncultivable fraction of endophytic bacteria, a clone library was established from the amplified 16S rDNA of total plant extract. Bacterial diversity within the clone libraries was analyzed by amplified ribosomal rDNA restriction analysis and by sequencing a clone for each identified operational taxonomic unit. The most abundant bacterial group was Mycobacterium sp., which was identified in the clone libraries of all analyzed Prunus genotypes. Other dominant bacterial genera identified in the easy-to-propagate genotypes were Rhodopseudomonas sp. and Microbacterium sp. Thus, the community structures in the easy- and difficult-to-propagate cherry genotypes differed significantly. The bacterial genera, which were previously reported to have plant growth-promoting effects, were detected only in genotypes with high propagation success, indicating a possible positive impact of these bacteria on in vitro propagation of P. avium, which was proven in an inoculation experiment. [ABSTRACT FROM PUBLISHER]

Extremophiles are potential resources for alkaline protease production. In order to search for alkaline protease producers, we isolated and screened alkaliphilic microorganisms from alkaline saline environments. The microorganism HSL10 was identified as a member of the genus Microbacterium by morphological observation, Gram staining and sequence analysis of the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region. By colony-forming unit counting under alkali or salt stress, it was further identified as an alkaliphilic microbe with mild halotolerance. In addition, it was capable of secreting alkaline proteases, evidenced by larger hydrolyzation zones in the skim milk-containing medium at pH 9.0 than at pH 7.0. Subsequently, we demonstrated that both NaCl and yeast extract significantly promoted protease production by HSL10. Finally, we established a sensitive colorimetric method for the detection of protease production by HSL10 under neutral and alkaline conditions, by using the Bradford reagent for substrate staining to improve the contrast between the hydrolyzation zone and the substrate background on agar plates. HSL10 was the first example of an alkaliphilic protease-producing member in Microbacterium, and its isolation and characterization have both academic and commercial importance. [ABSTRACT FROM AUTHOR]

Pitted keratolysis ( PK) is a plantar skin disorder mainly caused by coryneform bacteria. A common treatment consists of the topical use of erythromycin. Hyperhidrosis is considered a predisposing factor for bacterial proliferation and, consequently, for the onset of PK. The aim of this study was to evaluate the relationship between PK erythromycin and hyperhidrosis. All patients with PK seen in Sant' Andrea Hospital, between January 2009 and December 2011, were collected. PK was clinically and microscopically diagnosed. All patients underwent only topical treatment with erythromycin 3% gel twice daily. At the beginning of the study and after 5 and 10 days of treatment, a clinical evaluation and a gravimetric measurement of plantar sweating were assessed. A total of 97 patients were diagnosed as PK and were included in the study. Gravimetric measurements showed that in 94 of 97 examined patients (96.90%) at the time of the diagnosis, there was a bilateral excessive sweating occurring specifically in the areas affected by PK. After 10 days of antibiotic therapy, hyperhidrosis regressed together with the clinical manifestations. According to these data, we hypothesize that hyperhidrosis is due to an eccrine sweat gland hyperfunction, probably secondary to bacterial infection. [ABSTRACT FROM AUTHOR]

Background: Coryneform bacteria constitute an important segment of male urogenital microbiota. They have been generally considered as saprophytes, although some species have been associated with prostatitis as well. At the same time, biofilm infections have been suspected as a cause of prostatitis. Objective: To identify a set of coryneform bacteria isolated from semen of either healthy men or prostatitis patients applying different methods to reveal inter-assay variability and to determine their ability of adhesion and biofilm production. Design: Coryneform bacteria were identified by API Coryne 2.0 biochemical identification system and 16S rDNA sequencing using different primer sets. Quantitative assessment of biofilm production was performed using crystal violet binding assay method. Results: The most common species were Corynebacterium seminale, C. minutissimum, and Dermabacter hominis. Altogether 14 species and related genera were found. We observed the best inter-assay agreement when identifying C. seminale. Biofilm was observed in 7 out of 24 strains. The biofilm-producing strains belonged to Arthrobacter cumminsii, Dermabacter hominis, C. minutissimum, and Actinomyces neuii. No differences were found between the strains originating from prostatitis patients and healthy men. Dermabacter hominis strains were more potent biofilm producers than C. seminale strains (p=0.048). Conclusions: We can conclude that a wide variety of coryneform bacteria can be found from the male genital tract, although their exact identification is problematic due to insufficient representation in databases. Nearly one third of the strains are able to form biofilm that may give them an advantage for surviving several hostand treatment-related conditions. [ABSTRACT FROM AUTHOR]

Summary: The nematode Caenorhabditis elegans has been much studied as a host for microbial infection. Some pathogens can infect its intestine [1, 2], while others attack via its external surface [1, 3–6]. Cultures of Caenorhabditis isolated from natural environments have yielded new nematode pathogens, such as microsporidia and viruses [7, 8]. We report here a novel mechanism for bacterial attack on worms, discovered during investigation of a diseased and coinfected natural isolate of Caenorhabditis from Cape Verde. Two related coryneform pathogens (genus Leucobacter) were obtained from this isolate, which had complementary effects on C. elegans and related nematodes. One pathogen, Verde1, was able to cause swimming worms to stick together irreversibly by their tails, leading to the rapid formation of aggregated “worm-stars.” Adult worms trapped in these aggregates were immobilized and subsequently died, with concomitant growth of bacteria. Trapped larval worms were sometimes able to escape from worm-stars by undergoing autotomy, separating their bodies into two parts. The other pathogen, Verde2, killed worms after rectal invasion, in a more virulent version of a previously studied infection [6]. Resistance to killing by Verde2, by means of alterations in host surface glycosylation, resulted in hypersensitivity to Verde1, revealing a trade-off in bacterial susceptibility. Conversely, a sublethal surface infection of worms with Verde1 conferred partial protection against Verde2. The formation of worm-stars by Verde1 occurred only when worms were swimming in liquid but provides a striking example of asymmetric warfare as well as a bacterial equivalent to the trapping strategies used by nematophagous fungi [4]. [Copyright &y& Elsevier]

Sugarcane covers 8.53 million hectares with production of 596.63 million tonnes in Brazil. Despite its importance, little information is available on ratoon stunt ( RSD), caused by Leifsonia xyli subsp xyli (Lxx). Our objective was to examine the incidence and severity of Lxx among sugarcane cultivars in 2009, 2010 and 2011. Sap from 100 stalks from each field was sent for a routine RSD analyses that allowed examination of Lxx incidence. The presence of bacterium was checked by dot blot enzyme immunoassay to detect its presence and relative concentration. Analyses of 187 fields from 35 cultivars in 2009, 166 fields from 33 cultivars in 2010 and 221 fields from 30 cultivars in 2011 found Lxx incidence of 23.6% of fields of 23 cultivars in 2009, 27.1% of fields of 15 cultivars in 2010 and 25.8% of fields of 15 cultivars in 2011. RB867515, the major cultivar in Sao Paulo, had within-field incidence of up to 70% in 2009, 48% in 2010 and 88% in 2011. Highest incidence and populations of Lxx infection were found for cvs RB867515, RB855453, SP81-3250, RB855536 and RB92579, demonstrating their susceptibility to RSD. [ABSTRACT FROM AUTHOR]

Summary: Purpose: A prospective study was conducted to assess the role of coryneform bacteria in surgical site infections among obstetric and gynecological patients undergoing surgery. Materials and methods: The surgery was graded according to the degree of contamination, and surgical site infections (SSIs) were classified as superficial or deep. Pus samples were collected from SSIs according to rigorous aseptic precautions, and the quality of specimens was assessed by Q-score. A detailed clinical and treatment history was elicited from all patients. The samples were processed using standard protocols. Coryneform bacteria were considered significant pathogens only if they fulfilled rigorous clinical and microbiological criteria. Antibiotic susceptibility testing was performed using the Kirby–Bauer method according to the CLSI guidelines. Results: In total, 127 patients developed SSIs among 882 postoperative patients. Of these, 89 (70.1%) were culture positive: 40 (44.9%) were Gram-positive cocci, 27 (30.3%) were coryneform, and 22 (24.7%) were Gram-negative bacilli. All coryneform-infected patients had fever and post-operative wound dehiscence leading to a prolonged hospital stay. The most commonly isolated organism was Staphylococcus aureus (33.7%), followed by Corynebacterium amycolatum (11.2%), Escherichia coli (8.9%), Citrobacter spp. (7.8%) and coagulase-negative Staphylococci (6.7%). In our study, 45.5% were ESBL producers, 18.2% were Amp C producers, and 40% were MRSA. All the coryneform bacteria were multidrug resistant, and 51.8% of isolates were sensitive to only gatifloxacin and vancomycin. Symptomatic improvement was observed in all coryneform-infected patients after the administration of appropriate therapy. Conclusion: Coryneform bacteria appear to be emerging as significant nosocomial surgical site pathogens. The high level of multidrug resistance observed in coryneform bacteria in our study is cause for alarm. [Copyright &y& Elsevier]

Malonate semialdehyde decarboxylase from Pseudomonas pavonaceae 170 (designated Pp MSAD) is in a bacterial catabolic pathway for the nematicide 1,3-dichloropropene. MSAD has two known activities: it catalyzes the metal ion-independent decarboxylation of malonate semialdehyde to produce acetaldehyde and carbon dioxide and a low-level hydration of 2-oxo-3-pentynoate to yield acetopyruvate. The latter activity is not known to be biologically relevant. Previous studies identified Pro-1, Asp-37, and a pair of arginines (Arg-73 and Arg-75) as critical residues in these activities. In terms of pairwise sequence, MSAD from Coryneform bacterium strain FG41 (designated FG41 MSAD) is 38% identical with the Pseudomonas enzyme, including Pro-1 and Asp-37. However, Gln-73 replaces Arg-73, and the second arginine is shifted to Arg-76 by the insertion of a glycine. To determine how these changes relate to the activities of FG41 MSAD, the gene was cloned and the enzyme expressed and characterized. The enzyme has a comparable decarboxylase activity but a significantly reduced hydratase activity. Mutagenesis along with crystal structures of the native enzyme (2.0 Å resolution) and the enzyme modified by a 3-oxopropanoate moiety (resulting from the incubation of the enzyme and 3-bromopropiolate) (2.2 Å resolution) provided a structural basis. The roles of Pro-1 and Asp-37 are likely the same as those proposed for Pp MSAD. However, the side chains of Thr-72, Gln-73, and Tyr-123 replace those of Arg-73 and Arg-75 in the mechanism and play a role in binding and catalysis. The structures also show that Arg-76 is likely too distant to play a direct role in the mechanism. FG41 MSAD is the second functionally annotated homologue in the MSAD family of the tautomerase superfamily and could represent a new subfamily. [ABSTRACT FROM AUTHOR]

Background A series of unusual abortions occurred in Thoroughbred and Quarterhorse mares in the Hunter Valley region of New South Wales from mid- March to November 2004. The initial link between early cases was the microbiological culture of atypical environmental coryneforms from the stomach contents and/or lungs of fetuses aborted on different properties. Methods The unique pathologic lesions were described with a case definition and the term 'equine amnionitis and fetal loss' ( EAFL) was established. Results The causal factor was the ingestion of the processionary caterpillar ( Ochrogaster lunifer). Bacteria from the Actinomycetales order were isolated from 40% of the combined suspect and confirmed EAFL cases and included Microbacterium arborescens, Cellulomonas sp., Arthrobacter spp. and Cellulosimicrobium sp. Other bacteria isolated included various Gram-negative bacilli and Gram-positive cocci. Conclusions Although the predominant type of bacteria isolated from EAFL was environmental coryneforms, it is important to note that a variety of bacteria were associated with the characteristic histopathological changes outlined by the case definition. This highlights the importance of histopathology on both fetal membranes and fetuses, as well as culture to confirm EAFL and to exclude other possible causes of abortion. [ABSTRACT FROM AUTHOR]

Abstract: This manuscript describes the male genital tract microbiota and the significance of it on the host''s and his partner''s health. Microbiota exists in male lower genital tract, mostly in urethra and coronal sulcus while high inter-subject variability exists. Differences appear between sexually transmitted disease positive and negative men as well as circumcised and uncircumcised men. Upper genital tract is generally germ-free, except in case of infections. Prostatitis patients have frequently abundant polymicrobial communities in their semen, expressed prostatic secretion and/or post-massage urine. Coryneform bacteria have ambivalent role in male urogenital tract being frequently commensals but sometimes associated with prostatitis and urethritis. Interactions between male and female genital tract microbiota are highly likely yet there are very scarce studies on the couples’ genital tract microbiota. Increase of bacterial vaginosis-type microbiota and coliforms are the most typical findings in men while the adverse effect of male genital tract bacteria on in vitro fertilization and pregnancy outcome has also been indicated. [Copyright &y& Elsevier]

Abstract: In this work, a culture-independent approach, based on PCR-DGGE and RT-PCR-DGGE, has been used to study the succession of bacterial communities that are encountered in Fontina PDO cheese. As already found for other smear ripened cheeses, it appeared that coryneform bacteria were actively present and could therefore be considered determinant in rind formation. DGGE profiles, especially at the RNA level, have shown the presence of Brevibacterium, Corynebacterium and Arthrobacter genera. RT-PCR-DGGE gels have lead to a richer band profile than the one obtained on the basis of DNA analysis, thus indicating that RNA analysis can highlight bacterial species that DNA analysis is not able to show. Thus, the biodiversity of the Fontina PDO surface has been described better by means of RT-PCR-DGGE, and RNA molecules should be considered a more informative target than DNA. [Copyright &y& Elsevier]

Abstract: Escherichia coli expression system continues to dominate the bacterial expression systems and remain to be the preferred system for laboratory investigations and initial development in commercial activities or as a useful benchmark for comparison among various expression platforms. Some new developments in overcoming its shortcomings are reviewed in this paper, including antibiotics-free selection plasmids, extracellular production, and posttranslational modifications. The ability for E. coli to make mg glycosylated proteins promises even broader applications of the E. coli system in the future. Significant progresses have also been made over the past few years in alternative bacterial expression systems. Notably, the Lactoccocus lactis system has proven to be a viable choice for membrane proteins. Additionally, several Pseudomonas systems were developed and achieved product titers comparable to E. coli systems. Other bacterial systems such as Streptomyces, coryneform bacteria, and halophilic bacteria offer advantages in some niche areas, providing more choices of bacterial expression systems for recalcitrant proteins. [Copyright &y& Elsevier]

Abstract: Actinomyces hyovaginalis, an organism initially described from pigs, was recovered from nine sheep and a moufflon. Further strains of A. hyovaginalis were recovered from five samples from pigs over the same period. 16S rRNA sequencing and extensive phenotyping demonstrated high similarity between the ovine and porcine isolates; however differences with respect to erythritol, adonitol and l-arabitol fermentation were detected. Ovine isolates were made from various sample sites including abscesses and highlight the importance of the accurate identification of the various coryneform isolates which affect sheep. A. hyovaginalis can be added to the growing list of coryneforms which can cause disease in sheep including Corynebacterium pseudotuberculosis, Trueperella pyogenes and Arcanobacterium pluranimalium. [Copyright &y& Elsevier]

The rpoA gene, which encodes the α subunit of RNA polymerase, and the surrounding regions were cloned from Corynebacterium ammoniagenes (ATCC 6872), a parental strain of an industrial nucleotide producer in Korea. This region encodes genes for the following proteins (in order): initiation factor IF-1, the ribosomal proteins S13, S11 and S4, the α subunit of RNA polymerase and the ribosomal protein L17. Transcript mapping via reverse transcription polymerase chain reaction demonstrates that IF1, S13, S11, S4, α and L17 are transcribed as a polycistronic transcript from two tandem promoters preceding the IF-1 gene. The gene order of the C. ammoniagenes rpoA operon is characteristic of Corynebacteria. The rpoA gene encodes a protein of 334 amino acids with a deduced molecular weight of 35,971 Da, exhibiting 42 and 82% similarity to the Escherichia coli and Corynebacterium glutamicum α subunits, respectively. The regions that mediate interactions with β and β′ subunits and the residues that participate in the recognition of the UP element are conserved in the C. ammoniagenes α subunit. In contrast, there are differences between the C. ammoniagenes and E. coli α subunits in the residues assigned to the dimerization domain and the amino acids adjacent to conserved residues that mediate UP element recognition. The C. ammoniagenes rpoA gene expressed in E. coli complemented a temperature sensitive rpoA mutation, indicating that the C. ammoniagenes α subunit can function in E. coli. [ABSTRACT FROM AUTHOR]

A (−)γ-lactamase, Mhg, from Microbacterium hydrocarbonoxydans was over-expressed in E. coli and was characterized after purification. The maximum activity was at pH 8.0 and 60°C and the half life of Mhg was ~30 min at 75°C. The enzyme was activated by DTT. The catalytic triad of the (−)γ-lactamase is comprised of residues Ser98, Asp230, and His259 and an oxyanion hole was formed by Tyr32 and Met99 according to the alignment results. Under native conditions, the (−)γ-lactamase consists of two 31 kDa homodimers. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to assess the phenotypic and genotypic diversity of 56 Arcanobacterium haemolyticum isolates isolated from 51 patients attending primary health care centres and emergency units in the health area of Santander (Cantabria, northern Spain). Phenotypic characterization was based on morphological, biochemical, and antigenic tests. Species identification was confirmed by amplification and sequencing of the 16S rDNA gene. Antimicrobial susceptibility testing was determined by microdilution following the Clinical and Laboratory Standards Institute recommendations for coryneform bacteria. Genetic diversity was evaluated using BOX-PCR and pulsed-field gel electrophoresis. Eighty percent of the isolates had an identical BOX-PCR pattern, suggesting the spread of a single clone. The present report provides extensive information on the phenotypic and genotypic characterization of A. haemolyticum. [Copyright &y& Elsevier]

Actinobaculum schaalii is a new species that has so far been isolated from human blood, urine and pus. Its importance has probably been underestimated and other Actinobaculum spp. may also have been underdiagnosed. This retrospective study comprises all known cases of A. schaalii infections identified since 2004 in the canton of Neuchâtel (170 000 inhabitants), Switzerland. Strains were cultivated and isolated in the bacteriology laboratory using its routine procedure. Identification included a Rapid ID 32 A strip (bioMérieux) and 16S rRNA gene sequencing. Twenty-one positive samples were found in 19 patients (11 male, 8 female) of all ages (range 16-91 years): 10 from urine (50%), six from blood (30%), one from both blood and urine (5%), and three from pus (15%). Thirteen out of 17 (76%) cases with either blood or urine specimens had underlying genitourinary tract pathologies. When urine cultures were positive for A. schaalii, leucocytes were found in all samples (10/10, 100%) but all nitrite tests were negative (10/10, 100%). The onset of appropriate treatment was delayed due to the diminished sensitivity of A. schaalii to the antibiotics commonly used for UTIs (i.e. ciprofloxacin and trimethoprim/sulfamethoxazole) and to the delay in microbiological diagnosis. A. schaalii should specifically be searched in all cases of leukocyturia with a negative nitrite test but with Gram-positive rods in the Gram stain, in patients with underlying genitourinary tract pathology, instead of dismissing these findings as clinically irrelevant colonization by coryneform bacteria. This infection may be much more common than previously thought. [ABSTRACT FROM AUTHOR]

Gram-positive, yellow pigmented actinobacterium, strain S2-48 was isolated from water sample collected from the river Brahmaputra, Assam, India and subjected to a polyphasic taxonomic study. Most of the physiological and biochemical properties, major fatty acids (C Anteiso, iso C and C Anteiso), estimated DNA G+C content (70.2 mol%) and 16S rRNA gene sequence analysis showed that strain S2-48 belonged to the genus Microbacterium. Strain S2-48 exhibited highest 16S rRNA gene sequence similarity with Microbacterium testaceum (97.0%); however, the DNA-DNA relatedness value between strain S2-48 and M. testaceum was 9.1%. On the basis of differential phenotypic characteristics and genotypic distinctiveness, strain S2-48 should be classified within the genus Microbacterium as a novel species, for which the name Microbacterium assamensis is proposed. The type strain is S2-48 (=MTCC 10486 = DSM 23998). [ABSTRACT FROM AUTHOR]

cellulase-producing bacterial strain designated Z5 was isolated from the fecal matter of Zebra ( Equus zebra). The strain was identified as Microbacterium sp. on the basis of 16S rDNA sequence analysis. The effect of substrates like CMC, avicel, starch, maltose, sucrose, glucose, fructose, galactose, and lactose on cellulase production was also determined. Lactose as the sole carbon source induced cellulase production in this bacterial strain and a positive synergistic effect of lactose and CMC was also observed with enhancement of 3-4 times in cellulase activity. The optimum cellulase production was recorded with 3% CMC and 1% lactose when added individually in the Omeliansky's medium. The optimum temperature and time for cellulase production by this bacterial strain was 37°C and 10 days, respectively. To our knowledge this is the first report on enhancement of cellulase production by lactose in the Microbacterium sp. [ABSTRACT FROM AUTHOR]

Abstract: This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case–control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10 cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other bacteria, mainly Staphylococcus pseudintermedius alone (n =5) or in combination with Malassezia pachydermatis (n =5). Some coryneform isolates displayed resistance to fusidic acid or enrofloxacin, two antimicrobial agents commonly used for the treatment of otitis externa in dogs. The frequency of isolation of coryneform bacteria was 16% among 55 cases of canine otitis externa examined at the Danish hospital during 2007. In contrast, detectable levels of coryneform bacteria were not demonstrated in samples from the acustic meatus of 35 dogs with apparently healthy ears, attending the hospital during the same year. On basis of the current knowledge, these coryneform bacteria should be regarded as potential secondary pathogens able to proliferate in the environment of an inflamed ear canal. [ABSTRACT FROM AUTHOR]

The article discusses a study on mortality and pathogens responsible for the incidence of bloodstream infection (BSI) among Indigenous and non-Indigenous adults in the central Australian region. The potential contaminants in the positive blood cultures (BCs) collected from participants include coagulase-negative staphylococci and coryneform bacteria. Data on patient characteristics, outcomes and comorbid conditions such as chronic renal failure and chronic liver disease are given.

Rhodococcus equi is a gram-positive, coryneform bacterium that causes zoonotic infection mainly in horses and foals. It sometimes affects humans presenting as cavitary pneumonia. Immunocompromised patients, including HIV-infected patients, are more susceptible to R. equi infection. We present 10 cases of R. equi infection in HIV-positive patients admitted to our institute from 1991 to June 2008. Moreover, we have reviewed 272 cases of R. equi infection in HIV-infected persons, published from 1986 through 2008. With respect to the literature data, the R. equi strains isolated in our case series showed lower sensitivity to ceftriaxone, amoxicillin/clavulanic acid, and cotrimoxazole. Prompt diagnosis, early initiation of antiretroviral treatment and combined antimicrobial treatment seem to be effective to eradicate the infection and to improve the outcome. [ABSTRACT FROM AUTHOR]

The ability of the actinomycetes and coryneform bacteria isolated from the root tissues of winter rye to produce auxin in a liquid culture was studied. The isolates of coryneform bacteria produced indolyl-3-acetic acid ( IAA) into the medium in the amount of 9.0–95.0 μg/ml and the isolates of actinomycetes in the amount of 39.5–83.0 μg/ml. The maximal IAA accumulation in culture liquid of actinomycetes coincided, in general, with the beginning of the stationary growth phase. The dependences of IAA synthesis by actino-mycetes on the composition and pH of nutrient medium, tryptophan concentration, and aeration conditions were determined. Biological activity of the bacterial IAA was assessed. Treatment of winter rye seeds with coryneform auxin-producing bacteria increased the germination capacity and enhanced an intensive seedling growth in vitro. [ABSTRACT FROM AUTHOR]

Abstract: A novel method for the retention of arsenate [As(V)] combining time-controlled solid-phase extraction with living bacterial biomass is presented. As(V) retention was carried out by exposing the extractant, consisting of a living double-mutant of Corynebacterium glutamicum strain ArsC1-C2, to the sample for a retention time of 1–7min, before the arsenic distribution equilibrium between the sample solution and the extractant was established. The amount of As(V) retained in the biomass was measured by inductively coupled plasma-mass spectrometry (ICP-MS) after the sample had been treated with nitric acid. A theoretical model of the retention process was developed to describe the experimental retention-time profiles obtained with the bacterial cells. This relationship provided a feasible quantification of the retention process before steady-state was reached, providing that the agitation conditions and the retention time had been controlled. An analytical procedure for the retention/quantification of As(V) was then developed; the detection limit was 0.1ngAs(V)mL−1 and the relative standard deviation 2.4–3.0%. The maximum effective retention capacity for As(V) was about 12.5mgAs(gbiomass)−1. The developed procedure was applied to the determination of total arsenic in coal fly ash, using a sample that had undergone oxidative pre-treatment. [Copyright &y& Elsevier]

Abstract: The Biolog OmniLog Identification System (Biolog) and the 16S ribosomal RNA (rRNA) gene sequencing methods were compared to conventional microbiological methods and evaluated for accuracy of bacterial identification. These methods were evaluated using 159 clinical isolates. Each isolate was initially identified by conventional biochemical tests and morphological characteristics and subsequently placed into one of seven categories: aerobic Actinomycetes, Bacillus, Coryneforms, fastidious Gram-negative rods (GNR), non-fermenting GNR, miscellaneous Gram-positive rods (GPR), and Vibrio/Aeromonas. After comparison to the conventional identification, the Biolog system and 16S rRNA gene sequence identifications were classified as follows: a) correct to the genus and species levels; b) correct to the genus level only; or c) neither (unacceptable) identification. Overall, 16S rRNA gene sequencing had the highest percent accuracy with 90.6% correct identifications, while the Biolog system identified 68.3% of the isolates correctly. For each category, 16S rRNA gene sequencing had a substantially higher percent accuracy compared to the conventional methods. It was determined that the Biolog system is deficient when identifying organisms in the fastidious GNR category (20.0%). The observed data suggest that 16S rRNA gene sequencing provides a more accurate identification of atypical bacteria than the Biolog system. [Copyright &y& Elsevier]