Brevibacterium Species Research Articles

Brevibacterium enzymes as biological tools for ochratoxin A detoxification in dairy foods

The origin of ochratoxin A (OTA) in cheeses is mainly due to mould growth during the ripening process, and to a lesser extent, to the use of OTA-contaminated milk in cheese production. Bacterial smear-ripened cheeses developed a smear microbiota on their rind during ripening that greatly contributes to its typical aroma and texture. Bacteria from the Brevibacterium genus belong to the typical smear microbiota of cheeses. Type strains from Brevibacterium species frequently isolated from cheese and milk products were able to transform OTA into much less toxic ochratoxin α (OTα) and L-phenylalanine. Protein searches allowed the identification of a protein annotated as amidohydrolase in these OTA-degrader Brevibacterium strains. The OTA-hydrolytic activity of the identified amidohydrolase was demonstrated by the heterologous production of this protein from B. linens DSM 20425T (BlOTA). In vitro assays revealed that BlOTA transformed OTA into less toxic OTα, as well as ochratoxin B. When compared with other previously described OTA-degrading amidohydrolases, BlOTA exhibited optimal activity at a higher pH (8.0), while showing similar high temperature for optimal activity (55 °C) and thermostability; in addition, a clear preference for substrates with Phe, Tyr or Leu amino acid residues at the C-terminal position was clearly observed. BlOTA efficiently detoxifies OTA-contaminated bovine milk, without provoking changes on its free amino acid composition. Moreover, in silico predictions revealed that BlOTA is a non-allergenic, non-antigenic, and poorly immunogenic protein. Therefore, the QPS status possessed by cheese-Brevibacterium species, as well as the characteristics exhibited by BlOTA, make them suitable tools for the biological detoxification of OTA in dairy and food products.

Brevibacterium litoralis sp. nov., a cellulose-degrading strain isolated from marine surface sediment.

A Gram stain-positive, non-spore-forming, non-motile, short-rod actinomyces strain GXQ1321T was isolated from maritime surface sediments in Beihai (21° 41' 21.65″ N, 109° 05' 76.56″ E), Guangxi Zhuang Autonomous Region, and a number of categorization studies were performed. Following a period of 72h of incubation at a temperature of 30°C within a modified actinomycete culture medium, the colony was light-yellow, circular, smooth, central bulge, convex, opaque, with a 1.2-2.3mm diameter. Strain GXQ1321T had the ability to degrade cellulose. Chemotaxonomic studies revealed that the major methylnaphthoquinones in strain GXQ1321T was MK-8(H2). The most prevalent cellular fatty acids were anteiso-C19:0, anteiso-C15:0, anteiso-C17:0, and iso-C16:0. The whole-cell sugars of the strain GXQ1321T were identified rhamnose, xylose and glucose. Meso-diaminopimelic acid was found in the peptidoglycan hydrolysate, and the polar lipids were identified as diphosphatidylglycerol, three phosphoglycolipid, phosphatidylglycerol and two unknown glycolipid. This strain had 69.6% DNA G+C content. Strain GXQ1321T is classified as Brevibacterium based on its 16S rRNA gene sequence. It is closely related to Brevibacterium samyangense SST-8T (96.8%) and Brevibacterium rongguiense 5221T (96.3%). The average nucleotide identity (ANI) values of GXQ1321T and the above two type strains were 73.9-77.1%, and the digital DNA-DNA hybridisation (dDDH) values were 15.3-21.1%. Based on the phylogenetic, chemotaxonomic and physiological data, strain GXQ1321T was considered to be a novel species of the genus Brevibacterium, named Brevibacterium litoralis sp. nov, with the type strain GXQ1321T (= MCCC 1K08964T = KCTC 59167T).

Novel tetracycline resistance gene tet(65) located on a multi-resistance Corynebacterium plasmid.

Corynebacterium (C.) sp. 22KM0430 related to C. oculi and isolated from a dog exhibited resistance to tetracycline, and its WGS analysis revealed a putative resistance gene on a 35 562-bp plasmid also harbouring the MLSB resistance gene erm(X). To characterize the novel tetracycline resistance gene tet(65) and demonstrate its functionality by expression in C. glutamicum and Escherichia coli and plasmid curing of the host strain. tet(65) was cloned with and without its repressor tetR(65) and expressed in C. glutamicum DSM20300 and E. coli DH5α. Plasmid was cured by non-selective passages. Minimal inhibitory concentrations (MICs) of tetracyclines were determined according to CLSI guidelines. Association of tet(65) with efflux was shown by the addition of reserpine to MIC assays. Phylogenetic position and transmembrane structure of Tet(65) were analysed using MEGA11 and DeepTMHMM. Tet(65) shows 73% amino acid identity with the closest related Tet(Z), contains 12 transmembrane domains and is structurally related to the Major Facilitator Superfamily. The tetracycline MICs decreased in the plasmid-cured strain and increased when tet(65) was expressed in C. glutamicum and in E. coli. The MICs of tetracycline decreased in the presence of reserpine indicating that tet(65) functions as an efflux pump. A GenBank search also identified tet(65) in C. diphtheriae and Brevibacterium (B.) casei and B. luteolum. A novel tetracycline efflux gene tet(65) was identified in a C. oculi related species and was also present in the human pathogen C. diphtheriae and in Brevibacterium species indicating broader potential for dissemination.

Phenotypic and genomic characteristics of Brevibacterium zhoupengii sp. nov., a novel halotolerant actinomycete isolated from bat feces.

Two strictly aerobic, Gram-staining-positive, non-spore-forming, regular rod-shaped (approximately 0.7 × 1.9 mm) bacteria (HY170T and HY001) were isolated from bat feces collected from Chongzuo city, Guangxi province (22°20′54″N, 106°49′20″E, July 2011) and Chuxiong Yi Autonomous Prefecture, Yunnan province (25°09′10″N, 102°04′39″E, October 2013) of South China, respectively. Optimal growth is obtained at 25–28°C (range, 4–32°C) on BHI-5% sheep blood plate with pH 7.5 (range, 5.0–10.0) in the presence of 0.5–1.0% NaCl (w/v) (range, 0–15% NaCl [w/v]). The phylogenetic and phylogenomic trees based respectively on the 16S rRNA gene and 845 core gene sequences revealed that the two strains formed a distinct lineage within the genus Brevibacterium, most closely related to B. aurantiacum NCDO 739T (16S rRNA similarity, both 98.5%; dDDH, 46.7–46.8%; ANI, 91.9–92.1%). Strain HY170T contained MK-8(H2), diphosphatidylglycerol (DPG) and phosphatidylglycerol (PG), galactose and ribose as the predominant menaquinone, major polar lipids, and main sugars in the cell wall teichoic acids, respectively. The meso-diaminopimelic acid (meso-DAP) was the diagnostic diamino acid of the peptidoglycan found in strain HY170T. Anteiso-C15:0 and anteiso-C17:0 were the major fatty acids (> 10%) of strains HY170T and HY001, with anteiso-C17:1A predominant in strain HY170T but absent in strain HY001. Mining the genomes revealed the presence of secondary metabolite biosynthesis gene clusters encoding for non-alpha poly-amino acids (NAPAA), ectoine, siderophore, and terpene. Based on results from the phylogenetic, chemotaxonomic and phenotypic analyses, the two strains could be classified as a novel species of the genus Brevibacterium, for which the name Brevibacterium zhoupengii sp. nov. is proposed (type strain HY170T = CGMCC 1.18600T = JCM 34230T).Supplemental material for this article may be found at 10.1007/s12275-022-2134-8.

Brevibacterium Luteolum bacteremia: A case report and literature review

Brevibacterium species are to be opportunistic pathogens. Although rare, several case reports have mentioned infections ranging from cutaneous infections to bacteremia. Here, we present a case report describing a 64-year-old male pancreatic cancer patient diagnosed with B. luteolum bacteremia.

Brevibacterium limosum sp. nov., Brevibacterium pigmenatum sp. nov., and Brevibacterium atlanticum sp. nov., three novel dye decolorizing actinobacteria isolated from ocean sediments.

During a study of the marine actinobacterial biodiversity, a large number of Brevibacterium strains were isolated. Of these, five that have relatively low 16S rRNA gene similarity (98.5-99.3%) with validly published Brevibacterium species, were chosen to determine taxonomic positions. On the basis of 16S rRNA gene sequence analysis and BOX-PCR fingerprinting, strains o2T, YB235T, and WO024T were selected as representative strains. Genomic analyses, including average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH), clearly differentiated the three strains from each other and from their closest relatives, with values ranging from 82.8% to 91.5% for ANI and from 26.7% to 46.5% for dDDH that below the threshold for species delineation. Strains YB235T, WO024T, and o2T all exhibited strong and efficient decolorization activity in congo red (CR) dyes, moderate decolorization activity in toluidine blue (TB) dyes and poor decolorization in reactive blue (RB) dyes. Genes coding for peroxidases and laccases were identified and accounted for these strains' ability to effectively oxidize a variety of dyes with different chemical structures. Mining of the whole genome for secondary metabolite biosynthesis gene clusters revealed the presence of gene clusters encoding for bacteriocin, ectoine, NRPS, siderophore, T3PKS, terpene, and thiopeptide. Based on the phylogenetic, genotypic and phenotypic data, strains o2T, YB235T and WO024T clearly represent three novel taxa within the genus Brevibacterium, for which the names Brevibacterium limosum sp. nov. (type strain o2T = JCM 33844T = MCCC 1A09961T), Brevibacterium pigmenatum sp. nov. (type strain YB235T = JCM 33843T = MCCC 1A09842T) and Brevibacterium atlanticum sp. nov. (type strain WO024T = JCM 33846T = MCCC 1A16743T) are proposed.

Brevibacterium renqingii sp. nov., isolated from the Daqu of Baijiu.

Two bacterial strains, designated REN4T and REN4-1, were isolated from daqu sample collected from baijiu factory located in Shanxi, China. The two strains shared highly similar 16S rRNA gene sequences (99.67% identities) and formed a monophyletic clade within the Brevibacterium 16S rRNA gene tree, showing 97.56-97.85% 16S rRNA gene sequence identities with type strains Brevibacteriumpermense VKM Ac-2280T, Brevibacteriumsediminis FXJ8.269T, Brevibacterium oceani BBH7T and Brevibacterium epidermidis NCIMB 702286T. They contained MK-8(H2) as the most predominant menaquinone, antesio-C15:0, antesio-C17:0, Iso-C16:0 and Iso-C17:0 as the major cellular fatty acids, DPG (diphosphatidylglycerol), PG (phosphatidylglycerol), PGL (phosphatidylglycerollipids), and PL (phospholipids) as the main polar lipids. The genomic DNA G + C content of strains REN4 and REN4-1 were 64.35, 65.82mol%. Moreover, the low DNA-DNA relatedness values, physiological and biochemical characteristics, and taxonomic analysis allowed the differentiation of strains REN4T and REN4-1 from the other recognized species of the genus Brevibacterium. Therefore, strain REN4T represents a novel species of the genus Brevibacterium, for which the name Brevibacterium renqingii sp. nov. is proposed, with the type strain REN4T (= JCM 33953T = KCTC 49366T).

Comparative 16S rDNA metagenomics study of two samples of cassava peel heap from Nigeria and India.

The microbiology of many cassava products and the wastes generated during the processing have been reported; however, majority of these reports used culture-dependent methods. This has resulted in a dearth of information on the bacterial diversity of cassava peels and peel heaps. Large amounts of cassava peels generated during the processing of cassava root are usually discharged on land or water as wastes and are allowed to rot in the open, especially in some developing countries. Culture-independent methods such as PCR-based amplification and sequencing of 16S rRNA genes, among others have been used in recent times to study the diversity of microbes in different environmental samples. In this study, bacterial isolates were screened for cellulase and xylanase enzyme activities on minimal agar and genomic DNA was isolated from cassava peel samples; metagenomics was carried out using MiSeq2 × 300 with primers specific for V3-V4 bacterial region. Samples collected from Nigeria (AAG) had more species compared with samples from India (JHA) with 793 and 525 observed OTUs (operational taxonomic units), respectively. Five bacterial isolates from cassava peel-heap samples obtained from Ogbomoso, Nigeria showed no ability to produce cellulase enzyme, seven isolates from the Nigeria samples and three from Jorhat samples were positive for xylanase production; the highest amylase activity was shown by isolate AG18 (10,055U/mL), while the lowest was recorded for isolate JA2 (2333U/mL) with a significant difference observed in the amylase activities of isolates (p ≤ 0.05). Comparing the most abundant taxonomy for each of the samples at different taxonomic levels, the most abundant for sample AAG were phylum Firmicutes (42.11%), class Bacilli (41.27%), order Lactobacillales (33.11%), family Acetobacteraceae (31.30%), genus Acetobacter (30.02%) and unclassified species of Acetobacter (29.88%), while sample JHA had Actinobacteria (47.47%) as the highest phylum and class, order Actinomycetales (47.47%), family Brevibacteriaceae (46.97%), genus Brevibacterium (46.97%) and unclassified species of Brevibacterium (46.89%). This study provides an insight into the vast diversity of the bacteria associated with cassava peel heaps and the ability of some of the bacteria to produce selected extracellular enzymes.

152. Brevibacterium species: Case Series and Literature Review of an Emerging Opportunistic Cause of Bloodstream Infections

Background Brevibacterium species are non-motile, catalase-positive, obligate aerobic gram-positive bacilli. Colonies are yellow to gray-white, non-hemolytic, smooth, 6.5% sodium chloride tolerant. B. fermentans post neurosurgical meningitis was first described in 1969 in an infant. B. casei remains the most commonly isolated species (Table 4). The most commonly reported syndromes are bloodstream infections (BSIs) and endocarditis. Despite these reports, this organism continues to be listed on CDC’s NHSN commensal database.MethodsIsolates of Brevibacterium from clinical samples at Mayo Clinic, Rochester from January 1, 2014 to December 31, 2018 were identified. Charts were reviewed to determine patient demographics, immune status, source of culture, comorbidities, antibiotic susceptibility test (AST), length of stay (LOS) in hospital and intensive care unit (ICU), and mortality. Likelihood ratio (L-R) and Pearson correlation coefficient (PCC) of nominal data were calculated using the Chi-square test and Fischer exact test (FET). We defined statistical significance as P ≤ 0.05.ResultsWe identified 48 isolates from 45 unique patients, 46% were females. Distribution of age, hospital and ICU LOS, and time to culture growth, and AST data are shown in Table 1. 15.5% patients received allogeneic or autologous stem cell (SCT), or solid-organ transplant (SOT) recipients. 89% cultures were from sterile sources and 68.75% were blood cultures. Of these, 63.64% were monomicrobial. 62% of isolates identified to species level were B. casei. 5 patients were treated; an additional 10 received active antibiotics for other indications. Statistically significant variables are reported in Tables 2 and 3. Thirty-day mortality was 13%. This was higher in patients with bacteremia (L-R: 5.3 [P = 0.02]) but FET was not statistically significance (P = 0.15).ConclusionAccurate diagnosis of Brevibacterium may require molecular techniques. At our center, SCT or SOT recipient status and recent chemotherapy were associated with bacteremia. In these patients, this organism could represent an opportunistic cause of BSI. AST data suggest that Vancomycin offers a reasonable empiric treatment option. Additional data are needed to further define host populations in whom this organism presents pathogenicity. Disclosures All authors: No reported disclosures.

Indigenous South African essential oils as potential antimicrobials to treat foot odour (bromodosis)

Foot odour, known as bromodosis, is produced as a result of a combination of exocrine secretions and bacterial growth on the feet. Several commercial essential oils have demonstrated promise in inhibiting the growth of odour-causing bacteria as a novel strategy to offer relief from this dermatological problem. South Africa harbours an abundance of diverse indigenous flora which has shown favourable antimicrobial properties. As such, the potential application of natural products against bromodosis-causing Brevibacterium species with the aim of finding cosmetically appealing and promising African sourced essential oils capable of masking foot malodour was the focus of this study. The antimicrobial activity of 41 oils were investigated using the microdilution assay where the minimum inhibitory concentrations (MICs) were reported against Brevibacillus agri (ATCC 51663), Brevibacillus epidermidis (DSM 20660) and Brevibacillus linens (DSM 20425). Ninety-five percent of the oils tested displayed noteworthy activity (MIC ≤ 1.00 mg/mL) against B. agri with S. africana-caerulea demonstrating the highest activity (0.03 mg/mL) overall. Thirty-one essential oils displayed noteworthy activity (MIC ≤ 1.00 mg/mL) against B. epidermidis. Two essential oils (Plectranthus grandidentatus and Salvia africana-lutea) displayed noteworthy activity (MIC = 1.00 mg/mL) against B. linens. The major constituents for each oil was determined using gas chromatography coupled to mass spectrometry and limonene appears to be the most frequent essential oil constituent (23 of the oils). The olfactory properties of the essentials oils displaying noteworthy activity were further considered. These findings presenting interesting anti-bromodosis activity hold great potential, as not only do the selected oils have antimicrobial activity, but the pleasant aroma of these aromatic botanicals can further mask and control foot odour.

Brevibacterium paucivorans bacteremia: case report and review of the literature

BackgroundBrevibacteria are obligate aerobic gram-positive rods that are associated with milk products and are also found on human skin. Brevibacterium has been reported as a rare cause of catheter related blood steam infection mainly in immunocompromised hosts such as malignancies or AIDS patients.Case presentationA 94-year old woman, which had a past history of diabetes mellitus and chronic heart failure, presented with high fever associated with decreased oral intake and appetite loss and was admitted to our institute. A physical examination at the time of presentation was unremarkable. On day 2, both blood cultures collected on admission became positive with coryneform organism within 24 h without Staphylococci and Brevibacterium species were identified by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Subsequently, genetic investigation by 16S ribosomal RNA analysis was performed in order to identify the organism. Finally, the result identified this pathogen as Brevibacterium paucivorans with 99.5% homology on the Ez taxon database.The patient was started empirically on meropenem and teicoplanin for broad-spectrum antibiotic coverage. The patient’s fever finally abated and labs were also improved. On day 14, the antibiotic therapy was discontinued. The site of infections was unknown. We hereby report a case of Brevibacterium paicivorans bacteremia in an immunocompetent patient and review cases of Brevibacterium specises bacteremia previously reported. This is the first case of B. paucivorans bacteremia as far as we could search.ConclusionPhysicians and microbiologists should be aware that Brevibacteria are uncommon but important agents which could cause opportunistic infections in immunocompetent.

Brevibacterium anseongense sp. nov., isolated from soil of ginseng field.

Gram-positive, aerobic, non-motile, pale-yellow, and rodshaped bacterium, designated as Gsoil 188T, was isolated from the soil of a ginseng field in Pocheon, South Korea. A phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Brevibacterium and was most closely related to B. epidermidis NBRC 14811T (98.4%), B. sediminis FXJ8.269T (98.2%), B. avium NCFB 3055T (98.1%), and B. oceani BBH7T (98.1%), while it shared less than 98.1% identity with the other species of this genus. The DNA G + C content was 68.1 mol%. The predominant quinone was MK-8(H2). The major fatty acids were anteiso-C15:0 and anteiso-C17:0. The cell wall peptidoglycan of strain Gsoil 188T contained meso-diaminopimelic acid. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, and an unidentified aminolipid. The physiological and biochemical characteristics, low DNA-DNA relatedness values, and taxonomic analysis allowed the differentiation of strain Gsoil 188T from the other recognized species of the genus Brevibacterium. Therefore, strain Gsoil 188T represents a novel species of the genus Brevibacterium, for which the name Brevibacterium anseongense sp. nov. is proposed, with the type strain Gsoil 188T (= KACC 19439T = LMG 30331T).

Brevibacterium hankyongi sp. nov., isolated from compost.

A Gram-positive, strictly aerobic, non-motile, milky-white to creamy coloured and rod-shaped bacterium, designated BS05T, was isolated from compost. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that the strain formed a distinct lineage within the genus Brevibacterium and was most closely related to Brevibacterium avium NCFB 3055T (96.3 %), Brevibacterium oceani BBH7T (96.2 %) and Brevibacterium epidermidis NBRC 14811T (96.1 %). The DNA G+C content was 62.3 mol%. The predominant quinone was MK-8(H2). The major fatty acids were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0 and iso-C15 : 0. The cell-wall peptidoglycan of strain BS05T contained meso-diaminopimelic acid. The major polar lipid was phosphatidylglycerol. Moreover, the low sequence similarity of the 16S rRNA gene sequencing, physiological, biochemical and chemotaxonomic analyses allowed the phenotypic and genotypic differentiation of strain BS05T from the recognized species of the genus Brevibacterium. Therefore, strain BS05T represents a novel species of the genus Brevibacterium, for which the name Brevibacteriumhankyongi sp. nov. is proposed, with the type strain BS05T (=KACC 18875T=LMG 29562T).

Antimicrobial Essential Oil Combinations to Combat Foot Odour.

Foot odour (bromodosis) is an embarrassing and perplexing condition mostly caused by bacteria of the Brevibacterium species. Essential oils are a credible option as an affordable treatment of odour and contribute towards antimicrobial efficacy. Therefore, this study sets out to investigate the antimicrobial activity of essential oil combinations against odour-causing bacteria. The broth microdilution method was used to investigate the antimicrobial activity of 119 essential oil combinations, and the fractional inhibitory index was calculated to determine the interactive profile. Combinations that resulted in synergy in 1 : 1 ratios were further evaluated in different concentrations, and isobolograms were plotted to determine the influence of the ratio on overall activity. Numerous combinations could be identified as having synergistic interactions against the Brevibacterium spp. and no antagonism was observed. The combination of Juniperus virginiana (juniper) and Styrax benzoin (benzoin) demonstrated synergy against all three Brevibacterium spp. tested and J. virginiana was the essential oil responsible for the majority of the synergistic interactions. The results reported here confirm the promising potential of the majority of these oils and selected combinations in treating and controlling bromodosis.

Commercial Essential Oils as Potential Antimicrobials to Treat Skin Diseases.

Essential oils are one of the most notorious natural products used for medical purposes. Combined with their popular use in dermatology, their availability, and the development of antimicrobial resistance, commercial essential oils are often an option for therapy. At least 90 essential oils can be identified as being recommended for dermatological use, with at least 1500 combinations. This review explores the fundamental knowledge available on the antimicrobial properties against pathogens responsible for dermatological infections and compares the scientific evidence to what is recommended for use in common layman's literature. Also included is a review of combinations with other essential oils and antimicrobials. The minimum inhibitory concentration dilution method is the preferred means of determining antimicrobial activity. While dermatological skin pathogens such as Staphylococcus aureus have been well studied, other pathogens such as Streptococcus pyogenes, Propionibacterium acnes, Haemophilus influenzae, and Brevibacterium species have been sorely neglected. Combination studies incorporating oil blends, as well as interactions with conventional antimicrobials, have shown that mostly synergy is reported. Very few viral studies of relevance to the skin have been made. Encouragement is made for further research into essential oil combinations with other essential oils, antimicrobials, and carrier oils.

Brevibacterium sediminis sp. nov., isolated from deep-sea sediments from the Carlsberg and Southwest Indian Ridges.

Three actinobacterial strains, FXJ8.128, FXJ8.269T and FXJ8.309, were isolated from deep-sea sediments collected from the Carlsberg Ridge and Southwest Indian Ridge at depths of 3690, 1800 and 2461 m, respectively. The three strains had highly similar 16S rRNA gene sequences (99.8-99.9 % identities) and formed a monophyletic clade within the Brevibacterium 16S rRNA gene tree, showing 98.2-98.9 % 16S rRNA gene sequence identities with type strains Brevibacterium epidermidis NCIMB 702286T, Brevibacterium iodinum DSM 20626T, Brevibacterium linens DSM 20425T, Brevibacterium oceani BBH7T and Brevibacterium permense VKM Ac-2280T. All three isolates showed activity towards the breakdown of pectin and fluoranthene. They contained MK-8(H2) as the most predominant menaquinone, diphosphatidylglycerol, phosphatidylglycerol and a glycolipd as the main polar lipids, and anteiso-C15 : 0 and anteiso-C17 : 0 as the major cellular fatty acids. Moreover, the three isolates were distinguished readily from the phylogenetically related type strains by DNA-DNA hybridization values, by random amplified polymorphic DNA fingerprint profiles and by a range of physiological and biochemical characteristics. On the basis of the above polyphasic taxonomic data, strains FXJ8.128, FXJ8.269T and FXJ8.309 represent a novel species of the genus Brevibacterium, for which the name Brevibacterium sediminis sp. nov. is proposed. The type strain is FXJ8.269T (=CGMCC 1.15472T=DSM 102229T).

Bacterial Communities in Marine Salt Evaporate Rocks and Pristine Zechstein Aquifers

ABSTRACTSubsurface microorganisms dependent on local geological conditions of three groundwater wells reaching into Zechstein were investigated. An overlapping diversity could be shown, even if the wells have probing depths and belong to different locations in the Werra region, Germany. Actinobacteria is by far the most abundant phylum, followed by Proteobacteria. The most important differentiating factor between the groundwater aquifers was salt concentration, with increasing salinity leading to a decrease in bacterial abundance. The influence of Buntsandstein overlaying the Zechstein could be clearly seen with the aquifers, indicating mixed and diluted groundwater. A comparison of the isolated groundwater bacteria with those from salt samples of their lithostratigraphic origin in the marine evaporate rocks revealed lower cell counts and diversities of those microorganisms entrapped in the salt crystals, likely remaining from salt deposition during the Permian period. Similar prokaryotes were detected from both habitats, showing that Bacillus, Brevibacterium, and Oceanobacillus species are capable of surviving in extreme saline habitats and are typical representatives for Zechstein deposits.

Should Surgical Burs Be Used as Single-Use Devices to Avoid Cross Infection? A Case-Control Study

Objective: The purpose of this study was to evaluate and compare the rate of bacterial contamination of reused and new unused burs after different sterilization sessions. Materials and Methods: The test group consisted of 40 used fissure burs, and the control group of 40 unused new fissure burs (total n = 80). The burs from both groups were precleaned according to standard protocols and then subjected to two sterilization sessions (high- and low-steam pressure autoclaving). After each sterilization session, the burs were transferred into incubation tubes which contained thioglycollate culture medium and were monitored daily for a period of 48 h to detect any bacterial growth. Data were collected and statistical analysis was done using Fisher's exact test. Results: Of the 40 burs of the test group, 2 burs (5%) showed positive bacterial growth, whereas no bur from the control group showed any sign of bacterial growth after high-pressure autoclaving. The colony structure and Gram staining were compatible with the growth of Staphylococcus epidermis. After a second sterilization session at low-pressure steam autoclaving, no bacterial growth was observed for the test group, but 1 bur (2.5%) from the control group showed bacterial growth and Gram-positive staining matched well with the growth of Brevibacterium species. Conclusions: The new and unused burs were 100% sterile after high-pressure steam autoclaving, whereas 5% of the reused burs appeared positive with bacterial contamination. After low-pressure steam autoclaving, reused burs were 100% sterile, but 1 new bur demonstrated bacterial contamination.

Brevibacterium metallicus sp. nov., an endophytic bacterium isolated from roots of Prosopis laegivata grown at the edge of a mine tailing in Mexico.

A Gram-positive, aerobic, nonmotile strain, NM2E3(T) was identified as Brevibacterium based on the 16S rRNA gene sequence analysis and had the highest similarities to Brevibacterium jeotgali SJ5-8(T) (97.3 %). This novel bacterium was isolated from root tissue of Prosopis laegivata grown at the edge of a mine tailing in San Luis Potosí, Mexico. Its cells were non-spore-forming rods, showing catalase and oxidase activities and were able to grow in LB medium added with 40 mM Cu(2+), 72 mM As(5+) and various other toxic elements. Anteiso-C15:0 (41.6 %), anteiso-C17:0 (30 %) and iso-C15:0 (9.5 %) were the major fatty acids. MK-8(H2) (88.4 %) and MK-7(H2) (11.6 %) were the major menaquinones. The DNA G + C content of the strain NM2E3(T) was 70.8 mol % (Tm). DNA-DNA hybridization showed that the strain NM2E3(T) had 39.8, 21.7 and 20.3 % relatedness with B. yomogidense JCM 17779(T), B. jeotgali JCM 18571(T) and B. salitolerans TRM 45(T), respectively. Based on the phenotypic and genotypic analyses, the strain NM2E3(T) (=CCBAU 101093(T) = HAMBI 3627(T) = LMG 8673(T)) is reported as a novel species of the genus Brevibacterium, for which the name Brevibacterium metallicus sp. nov., is proposed.

Isolation and Identification of Brevibacterium Species from Dairy Product and some Clinical Specimens

Isolation and Identification of Brevibacterium Species from Dairy Product and some Clinical Specimens