Systematic Bacteriology Research Articles

Potential Thermotolerant Lactobacilli Isolated from Chicken Gastrointestinal Tract for Probiotic Use in Poultry Feeds

This research was carried out to isolate and identify thermotolerant lactobacilli from broiler chicken gastrointestinal tract from Dhaka, Bangladesh. Twenty five thermotolerant Lactobacillus strains were isolated and identified as Lactobacillus species based on cultural characteristics, biochemical tests, and sugar fermentation. The probiotic are a live microbial feed supplements which positively affects the health of the host animal by improving its intestinal balance.The results showed only four among twenty five isolates were highly responded to probiotic criteria such as low pH tolerance (2.5), bile salt tolerance (2%) and sodium chloride salt tolerance (5%) in vitro, and were identified strains as Lactobacillus plantarum img-02, Lactobacillus plantarum img-08, Lactobacillus plantarum img-10 and Lactobacillus acidophilus img-14 according to Bergey’s Manual of Systematic Bacteriology. Four isolates grow enough at 45°C and two isolates (Lactobacillus plantarum img-10 and Lactobacillus acidophilus img-14) heat stable at 60°C for 30 min. All the strains were showed protease activity on skim milk agar. These strains were resistance to commercial antibiotic ciprofloxacin, gentamycin, imipenem and penicillin G but sensitive to ampicillin, doxycycline, erythromycin and tetracycline; also have antimicrobial activity against common pathogen such as ATCC of Salmonella enteritidis, Staphylococcus aureus, Listeria monocytogenes, Shigella flexneri, Bacillus cereus, Klebsiella pneumonia, Escherichia coli (environmental isolates), Aspergillus flavus and Candida albicans. This study concludes that these isolates may be used as potential candidate as probiotic poultry feed.
 Bangladesh J Microbiol, Volume 36 Number 2 December 2019, pp 63-68

Purification and Characterization of an Antibacterial Substance from Aerococcus urinaeequi Strain HS36.

A bacterial strain inhibiting the growth of Vibrio anguillarum, the causative agent of vibriosis, was isolated from fish intestines. The isolated strain HS36 was identified as Aerococcus urinaeequi based on the characteristics of the genus according to Bergey's Manual of Systematic Bacteriology and by 16S rRNA sequencing. The growth rate and antibacterial activity of strain HS36 in shaking culture were higher than those in static culture, while the optimal pH and temperature for antibacterial activity were 7.0 and 30°C, respectively. The active antibacterial substance was purified from a culture broth of A. urinaeequi HS36 by Sephadex G-75 gel chromatography, Sephadex G-25 gel chromatography, and reverse-phase high-performance liquid chromatography. Its molecular weight, as estimated by Tricine SDS-polyacrylamide gel electrophoresis, was approximately 1,000 Da. The antibacterial substance produced by strain HS36 was stable after incubation for 1 h at 100°C. Although its antibacterial activity was optimal at pH 6-8, activity was retained at a pH range from 2 to 11. The purified antibacterial substance was inactivated by proteinase K, papain, and β-amylase treatment. The newly purified antibacterial substance, classified as a class II bacteriocin, inhibited the growth of Klebsiella pneumoniae, Salmonella enterica, and Vibrio alginolyticus.

Isolation and Characterization of Vibrio parahaemolyticus in the hepatopancreas of cultured white pacific shrimp - Litopenaeus vannamei

Vibrio parahaemolyticus is the most common species among crustaceans, often causing various diseases and significant losses in aquaculture. Acute hepatopancreatic necrosis disease (AHPND) is a newly emerging shrimp disease that has severely damaged the global shrimp industry. This species of bacteria is associated with gastrointestinal illness in humans and has been implicated in foodborne disease. The present study carried out, isolation and characterization of pathogenic bacterial flora isolated from the infected hepatopancreas of vannamei, obtained from various aquafarms in Andhra Pradesh, India, on 11th June 2018. The collected samples were plated on TCBS- (Thiosulfate-Citrate-Bile salt-Sucrose) agar medium and Hi -Chrome vibrio, as described in Bergey's manual of systematic bacteriology. Isolated colonies were subjected to the following tests- microscopic examination, growth at different temperatures, growth at different NaCl concentrations, and biochemical tests. Further purity, maintenance, and propagation of purified cultures were done. The microbial culture was identified using 16s rRNA molecular technique. Phylogenetic Evolutionary analyses and distance matrix were conducted in MEGA7.In the present study, different samples were screened, a total of three green colonies (V44, V45, V46) were isolated, identified by biochemical tests and genetic identification as Vibrio parahaemolyticus. A systematic methodology has been developed to isolate and characterize Vibrio sp. from diseased shrimp and identify them by genetic analysis

Isolation And Characterization Of Lactic Acid Bacteria (Lab) From Small Intestine Content Of Duck (Anas Sp.) As A Probiotic Candidate

A group of lactic acid bacteria (LAB) as a probiotic agent have been known to have a beneficial effect on health chicken. The objectives of this study were to isolate, characterize and determine of the LAB which originated from the small intestine content of domestic duck (Anas sp.) for candidate of probiotic. Isolation, selection and identification of bacteria was done using de Man Rogosa Sharpe (MRS) agar + 1% bromocresol purple. Characterization of bacteria based on morphological by Gram staining methods, and identification of biochemical characters using catalase activity, and Triple Sugar Iron Agar (TSIA). The data of isolate confirmed to Bergey’s Manual of Systematic Bacteriology. This research carried out on the Microbiology Laboratory, Microbiology Study Program, Yala Radjabhat University (YRU), Faculty of Science and Agriculture.The results showed that according to physiological and biochemical characteristics in various media, the bacteria had Gram +, catalase -, coccus in shape, and were able to ferment glucose to be lactic acid. Based on the result, it is concluded that the LAB isolate shows a similar characteristic to the member of genus Lactobacillus sp. The isolated bacteria shows characteristic resistance to acidic pH and bile salts so the bacteria were fulfilled as a probiotic candidate.

Rule 24b of the International Code of Nomenclature of Prokaryotes and regulating the priority of names and epithets considered to be associated with heterotypic synonyms.

Rule 24b of the International Code of Nomenclature of Prokaryotes regulates the priority of names that are considered to be heterotypic synonyms. However, the rule is imperfect because it caters only for names that compete for priority that were only included on the Approved Lists of Bacterial Names or for names that were only validly published in the International Journal of Systematic Bacteriology or the International Journal of Systematic and Evolutionary Microbiology, either in an original article or via the Validation Lists. Although this should be self-explanatory, Rule 24b does not cater for what happens when one or more names considered to be heterotypic synonyms have appeared on the Approved Lists of Bacterial Names while other names also considered to be heterotypic synonyms were validly published in the International Journal of Systematic Bacteriology or the International Journal of Systematic and Evolutionary Microbiology, either in an original article or via the Validation Lists. Formal changes to the International Code of Nomenclature of Prokaryotes are required.

Taking a Closer Look at the Valid Publication and Authorship of Legionella bozemanae Brenner et al. 1980, Fluoribacter bozemanae Garrity et al. 1980, Legionella pittsburghensis Pasculle et al. 1980, Legionella micdadei Hébert et al. 1980 and Tatlockia micdadei (Hébert et al. 1980) Garrity et al. 1980.

The names Legionella bozemanae Brenner et al. 1980, Fluoribacter bozemanae Garrity et al. 1980, Legionella pittsburghensis Pasculle et al. 1980, Legionella micdadei Hébert et al. 1980 and Tatlockia micdadei (Hébert et al. 1980) Garrity et al. 1980, all appeared in the same issue of the International Journal of Systematic Bacteriology. Fluoribacter bozemanae Garrity et al. 1980 appeared as the name of new taxon at the rank of species and Tatlockia micdadei (Hébert et al. 1980) Garrity et al. 1980 as a new combination, both in the same original article in the International Journal of Systematic Bacteriology. The names Legionella bozemanae Brenner et al. 1980 (originally published as Legionella bozemanii) Legionella pittsburghensis Pasculle et al. 1980 (originally published as Legionella pittsburgensis) and Legionella micdadei Hébert et al. 1980, all appeared initially in effective publications outside of the International Journal of Systematic Bacteriology and were validly published by inclusion in Validation List no 5. While it is evident from the inclusion of the names Legionella bozemanae Brenner et al. 1980, Legionella pittsburghensis Pasculle et al. 1980 and Legionella micdadei Hébert et al. 1980 on Validation List no. 5 that the authors were following the 1975 revision of the International Code of Nomenclature of Bacteria, the wording of Garrity et al. 1980 indicates that they were following the interpretation found in the 1966 revision of the International Code of Nomenclature of Bacteria. Changes to the International Code of Nomenclature of Bacteria between the 1966 and 1975 revisions introduced new criteria for the valid publication of names. In particular, there was a change from all effective publications being accepted as the publication in which valid publication of a name could occur to only one journal being accepted as the publication in which valid publication could occur (the International Journal of Systematic Bacteriology, now the International Journal of Systematic and Evolutionary Microbiology). This change has a direct effect on the order of valid publication of the names Legionella bozemanae Brenner et al. 1980, Fluoribacter bozemanae Garrity et al. 1980, Legionella pittsburghensis Pasculle et al. 1980, Legionella micdadei Hébert et al. 1980 and Tatlockia micdadei (Hébert et al. 1980) Garrity et al. 1980, their authorships, as well as determining which names should be treated as names of new taxa at the rank of species (sp. nov.) vs new combinations (comb. nov.) based on the names of existing taxa. Given the fact that Legionella pittsburghensis Pasculle et al. 1980, Legionella micdadei Hébert et al. 1980 and Tatlockia micdadei (Hébert et al. 1980) Garrity et al. 1980 share the same nomenclatural type, this also has an influence on which epithet has priority and which epithet is illegitimate.

Isolation and identification of a strain producing riboflavin

Aim. Aim of investigation was to receive riboflavin strain-producers using natural sources for development of riboflavin technology. Methods. Strain-producers were isolated by the method of imprints (replica). The identification of stains was done by commonly used techniques using the «Bergey's Manual of Systematic Bacteriology». The resulting clones were tested for accumulation of riboflavin by fluorometric method. Results. 9 natural sources (seeds of corn and potato tubers) were investigated, pure cultures of microorganisms werr isolated and their identification was carried out. Two types of bacterial colonies of the genus Bacillus were identified. Selected strains weretested for antibiotic susceptibility and for the ability to accumulate riboflavin. Conclusions. As a result of the research, strain-producing riboflavin is isolated, the strain is classified as B. subtilis. The strain accumulated 4.3 g / l of riboflavin in a sucrose medium during a 72 hours cultivation. This strain was accepted as a source for the development of riboflavin technology.
 Keywords: riboflavin, stain, microbial synthesis, Bacillus subtilis.

Trait-based analysis of the human skin microbiome

BackgroundThe past decade of microbiome research has concentrated on cataloging the diversity of taxa in different environments. The next decade is poised to focus on microbial traits and function. Most existing methods for doing this perform pathway analysis using reference databases. This has both benefits and drawbacks. Function can go undetected if reference databases are coarse-grained or incomplete. Likewise, detection of a pathway does not guarantee expression of the associated function. Finally, function cannot be connected to specific microbial constituents, making it difficult to ascertain the types of organisms exhibiting particular traits—something that is important for understanding microbial success in specific environments. A complementary approach to pathway analysis is to use the wealth of microbial trait information collected over years of lab-based, culture experiments.MethodsHere, we use journal articles and Bergey’s Manual of Systematic Bacteriology to develop a trait-based database for 971 human skin bacterial taxa. We then use this database to examine functional traits that are over/underrepresented among skin taxa. Specifically, we focus on three trait classes—binary, categorical, and quantitative—and compare trait values among skin taxa and microbial taxa more broadly. We compare binary traits using a Chi-square test, categorical traits using randomization trials, and quantitative traits using a nonparametric relative effects test based on global rankings using Tukey contrasts.ResultsWe find a number of traits that are over/underrepresented within the human skin microbiome. For example, spore formation, acid phosphatase, alkaline phosphatase, pigment production, catalase, and oxidase are all less common among skin taxa. As well, skin bacteria are less likely to be aerobic, favoring, instead, a facultative strategy. They are also less likely to exhibit gliding motility, less likely to be spirillum or rod-shaped, and less likely to grow in chains. Finally, skin bacteria have more difficulty at high pH, prefer warmer temperatures, and are much less resilient to hypotonic conditions.ConclusionsOur analysis shows how an approach that relies on information from culture experiments can both support findings from pathway analysis, and also generate new insights into the structuring principles of microbial communities.

Semut sebagai vektor mekanik bakteri di dalam gedung Balai Litbang P2B2 Tanah Bumbu, Kalimantan Selatan: studi pendahuluan

Ants are now now noticeable as a mechanical vector of pathogenic bacteria, some of which have been resistant to certain antibiotics. Its wide presence allows ants to easily transmit disease agents. This study aims to determine the type of ants in Balai Litbang P2B2 Tanah Bumbu and possible role as a vector mechanical bacteria. This research was conducted at Balai Litbang P2B2 Tanah Bumbu from August to September 2017, the sample was obtained from 15 rooms by using the sugar solution feed placed in the microtube, then the ant was identified by referring to Key to Identifying Common Household Ants and Pictorial Key to the Common Urban Ants of North Carolina, followed by identification of bacteria on selective and biochemical media referring to Bergey's Manual of Systematic Bacteriology Volume 2. Out of a total of 16 samples, five types of ants are known: Tapinoma melanochephalum, Paratrechina longicornis, Tetramorium caespitum, and Anoplolepis gracilipes , and Solenopsis spp. Bacteria are found in all types of ants. The bacteria identified were Bacillus alvei, Bacillus badius, Bacillus insulitus, Serratia liquefaciens, Enterobacter aglomerans, and Klebsiella ozonae, and Enterobacter spp. The ants found in Balai P2B2 Tanah Bumbu are potentially bacterial mechanical vectors.

Distinctive antagonistic role of new Enterococcus faecium ER-3M strain and its bacteriocin effect against Staphylococcus aureus Pneumonia

Bacteriocins secreted by some bacteria such as Enterococcaceae has a protected role against Staph. aureus pneumonia. This study identified a new Enterococcus sp. that produces efficient bacteriocin which attenuates Staph. aureus pneumonia in rats. Identification of Enterococcus sp. was achieved according to Bergey’s manual of systematic bacteriology using 16S rRNA analysis. Bacteriocin was extracted, partially purified and characterized. Antagonistic activity of the bacterial cells or its bacteriocin was estimated in vitro against different pathogenic bacteria and in vivo with an animal experiment, where histopathological and hematological examinations were evaluated. The isolate was identified as Ent. faecium ER-3M, with accession number KY774316. It exhibits broad antimicrobial spectrum against Gram-positive and Gram-negative organisms in vitro. Treatment of rats with bacterial cells or bacteriocin (500 Au mg−1), previously infected with Staph. aureus, significantly decreased the symptoms, WBCs, neutrophils, and liver functions. Histopathological examination of rat lung tissues revealed that treatment with probiotic bacteria and/or its bacteriocin can attenuate the pneumonic lesions caused by Staph. aureus bacteria. Partially purified bacteriocin was characterized by a large molecular weight of approximately 40 kDa a proteinous nature according to both Fourier transform infrared spectrometry (FTIR) spectroscopy and 1H-Nuclear magnetic resonance (NMR) analysis and belongs to class III of bacteriocins termed enterolysin. Based on the results, the successful treatment of Ent. faecium ER-3M or its bacteriocin may be one of the promising treatments against Staph. aureus pneumonia.

ISOLATION, SCREENING AND DETERMINATION OF Α-AMYLASE ACTIVITY FROM MARINE STREPTOMYCES SPECIES

Objective: This study was aimed to isolate potent amylase producing Streptomyces from the marine source.Methods: Soil samples were collected from less explored mangrove regions of Muthupet, Tamilnadu. Isolation of Streptomyces was performed by serial dilution plate technique using starch casein agar (SCA) (pH 7.2 and temp 28 °C). Morphological and biochemical characteristics were studied using Bergey’s manual of systematic bacteriology. Preliminary screening and quantification of amylase activities were analysed in selected Streptomyces isolates by starch agar plate and dinitrosalicylic acid (DNS) method respectively.Results: Totally 65 isolates were separated from the marine soil. Among them, 23 strains showed different morphological features. These strains were subjected to amylase activity. Eight Streptomyces isolates (S1-S8) exhibited positive for amylase activity. The zone of clearance was exhibited in the range of diameters between 4-20 mm. Fermentation was prompted with inorganic salt starch agar, international Streptomyces project (ISP-4) media at 28 °C and incubated in an orbital shaker at 250 rpm for 96 h (pH 7.5). The quantitative estimation of amylase activity was exhibited selected eight isolates in the range between 2.4±0.002-5.9±0.005 (U/ml). The Streptomyces species S4, S5 and S6 exhibited strong amylase activity in both qualitative and quantitative level.Conclusion: This work motivating the amylase producing Streptomyces are originated in mangroves and it proved Streptomyces sp. S6 has a more efficient source of amylase production.

Isolation and Identification of Streptococcus parauberis From Freshwater Fish in Turkey

Streptococcus parauberis is an alpha-hemolytic gram positive coccoid bacterium belonging to the Streptococcaceae family. This bacterium cause streptococcosis is a major disease in cultured fish due to the intensification of aquaculture and causes significant economic losses in fish farm industry. In our study, we isolated a total of 37 lactic acid bacteria from wild fish ( Sander lucioperca , Carassius gibelio , Cyprinus carpio ) of Lake Eğirdir and cultured fish ( Oncorhynchus mykiss , Walbaum) of farm in Turkey. For the isolation of bacteria phenotypic and biochemical characteristics of the 37 isolates obtained from the colonies grown on MRS, TSA and M17 agar characterized by determining colony morphology, cell morphology, motility, gram staining and the production of cytochrome oxidase and catalase. Further biochemical characteristics were determined using conventional tests according to Bergey’s Manual of Systematic Bacteriology. From the isolated lactic acid bacteria 25 of were identified as S. parauberis , 2 of as Vagococcus sp., 2 of as Lactococcus garvieae and 5 of as Lactococcus lactis by culture-based, biochemical test and 16Sr RNA gene sequencing techniques but 3 of them couldn’t (F65, F49 and F50) identified. In this study, the main objective of us is to identify S. parauberis with conventional and 16Sr RNA gene sequencing techniques from wild fish in Lake Eğirdir and in cultured fish in fish farm of Egirdir-Turkey.

Bio-chemical characterization of rhizobia isolated from root nodules of Velvet bean (Mucuna pruriens L.)

Rhizobia are the symbiotic bacteria found in the soil which have potential ability to convert atmospheric di-nitrogen into usable form. A total of ten rhizobial strains were isolated from the root nodules of a medicinal legume Mucuna pruriens (L.) that commonly grow in the foothills of the Himalaya. All the ten strains isolated from different locations of same area were morphologically, biochemically and physiologically characterized based on the Bergey’s Manual of systematic Bacteriology. They were tested for the antibiotics sensitivity. The isolates showed high sensitivity to amoxicillin and least to erythromycin. Authentication test was done in eleven legumes but shown nodulations only in Trigonella foenum-graecum, Mucuna pruriens and Medicago sativa. The morphology, physiology, biochemical and infection test studies carried out justifies that the bacteria isolated belonged to the species of Rhizobium meliloti.

Biodiversity of Bacteria Isolated from Home-Made Wine and Vinegar

Wine is an alcoholic beverage made grapes fermented without the addition of sugars, acids, enzymes, water. It has been consumed by human beings in religious ceremonies since ancient times. Vinegar is sour juice that is used as a sweetener in meals, in salads, or as a preservative such as brine. It has a great variety of industrial, medical, and domestic uses are still commonly practiced today. The aim of this study was to determine the bacterial biodiversity of home-made wine and vinegar using classic and molecular methods. Morphological, cultural and biochemical identifications were made according to the Bergey’s Manual of Systematic Bacteriology. For molecular identification 16S rDNA-PCR method was used. PCR results of these samples were send to the sequencing. BLASTn software was used to match our sequences with the ones in GenBank. In this study, bacteria colonies were isolated from home-made wine and vinegar. According to molecular results acetic acid and lactic acid bacteria were found.

Minimal standards for describing new species belonging to the families Campylobacteraceae and Helicobacteraceae: Campylobacter, Arcobacter, Helicobacter and Wolinella spp.

Ongoing changes in taxonomic methods, and in the rapid development of the taxonomic structure of species assigned to the Epsilonproteobacteria have lead the International Committee of Systematic Bacteriology Subcommittee on the Taxonomy of Campylobacter and Related Bacteria to discuss significant updates to previous minimal standards for describing new species of Campylobacteraceae and Helicobacteraceae. This paper is the result of these discussions and proposes minimum requirements for the description of new species belonging to the families Campylobacteraceae and Helicobacteraceae, thus including species in Campylobacter, Arcobacter, Helicobacter, and Wolinella. The core underlying principle remains the use of appropriate phenotypic and genotypic methods to characterise strains sufficiently so as to effectively and unambiguously determine their taxonomic position in these families, and provide adequate means by which the new taxon can be distinguished from extant species and subspecies. This polyphasic taxonomic approach demands the use of appropriate reference data for comparison to ensure the novelty of proposed new taxa, and the recommended study of at least five strains to enable species diversity to be assessed. Methodological approaches for phenotypic and genotypic (including whole-genome sequence comparisons) characterisation are recommended.

Screening of efficient rhizobacteria associated with cauliflower (Brassica oleraceavar. botrytis L.) for plant growth promoting traits

In the current study, a total of 25 isolates were isolated from the rhizosphere and roots of cauliflower (Brassica oleraceavar. botrytis L.) from the vicinity of Una district of Himachal Pradesh. The isolates were tested in vitro for their ability to solubilise phosphorous and produce siderophore, indole acetic acid (IAA), hydrogen cyanide (HCN) and antifungal metabolites against the soil borne pathogens. Results revealed that out of 25, only 4 rhizospheric isolates (SB5, SB11, SB8 and SB10) have maximum plant growth promoting attributes. The isolates were identified as Bacillus sp. on the basis of Bergey’s manual of systematic bacteriology. The isolate SB11 recorded highest phosphate solubilizing efficiency in solid medium (109.09%) and in liquid medium (350?g/ml). Maximum production of IAA (51.96?g/ml), siderophore (91.41%) and HCN were also observed for the same isolate. Further-more, the isolate SB11 produced highest antifungal metabolite production against Rhizoctoniasolani(37.11%), Sclerotiniasclerotiorum(41.11%), and Pythium sp. (71.11%) causing root rot, stalk rot and damping off diseases in cauliflower, respectively. The selected isolate (SB11) showed optimum growth at a pH of 7.0, 35°C temperature and 2% NaCl. On the basis of multifarious PGP-traits the SB11 isolate has tremendous potential to be used as a bioferti-lizer/bioprotectant for growth promotion and natural protection of cauliflower under low hill conditions of Himachal Pradesh.

IN VITRO STUDY ON RELEASE OF BIOACTIVE ANTIMICROBIAL COMPOUNDS FROM DAIRY PRODUCTS BY CERTAIN PROMISING PROBIOTIC LACTOBACILLUS STRAINS

Objective: The antimicrobial activity and Probiotic properties of Lactobacillus species were evaluated. The antimicrobial compound of potent antimicrobial probiotic Lactobacillus was purified by column chromatography and its nature and stability were determined.Methods: This investigation was performed with few Lactobacillus strains of ATCC and MTCC along with certain strains isolated from different dairy sources. They were evaluated for their probiotics properties (acid tolerance, bile tolerance, bile salt hydrolase activity, cell autoaggregation, cell surface hydrophobicity and haemolytic behaviour). Agar well diffusion method was used to screen their potency to release bioactive compound against several pathogens. This potent antimicrobial compound was purified by chromatography as well as its molecular mass was estimated by following SDS-PAGE. Finally, the stability of the compound was determined against various ranges of temperature and pH.Results: Among all Lactobacillus strains, R1 was found to be a potent probiotic strain as well as cell free supernatant (CFS) of R1 showed more strong antagonistic effect against most of the pathogens. Carbohydrate fermentation and physiological characterization of strain R1 matched with Lactobacillus fermentum as per Bergey’s manual of systematic bacteriology. The molecular mass of the purified fraction was estimated at approximately 25 kDa and could be stable after heat treatment of 100 °C for 30 min and pH range of 4.5-7.0Conclusion: R1 showed highest antimicrobial activity while it has been found as Lactobacillus fermentum. It is due to the release of a bioactive compound having a molecular mass of 25 kDa.

Bacterial Biodiversity of Industrial Soils from Aydın and Trabzon Province

The aim of this study was to determine bacterial biodiversity of industrial soils from Aydin and Trabzon Province using morphological, cultural, biochemical and molecular methods. Factory wastes, detergents, pesticides and gasoline are accepted as pollutants to the environment. In this study a total of 65 samples which can tolerate xylene, acetone, chloroform and methanol were acquired. According to the Bergey’s Manual of Systematic Bacteriology morphological, cultural and biochemical tests, 48 of these samples were found to be Bacillus sp . and 17 of them were found to be Pseudomonas sp . For molecular identification 16S rDNA-PCR method was used. Seven different genera and a total of sixteen species were found as a result of the study.

Heterocyte-forming cyanobacteria from Brazilian saline-alkaline lakes

Studies investigating the diversity of cyanobacteria from tropical environments are scarce, especially those devoted to the isolation and molecular characterization of the isolated strains. Among the Brazilian biomes, Pantanal has mainly been examined through microscopic observation of environmental samples, resulting in lists of morphotypes without any genetic information. Recently, two studies were conducted evaluating the morphologic and genetic diversity of cultured non-heterocytous cyanobacteria in this biome, which resulted in the separation and description of two novel genera. In order to complement the diversity of cultured cyanobacteria from saline-alkaline lakes in Pantanal, the present study is dedicated to the examination of cultured nitrogen-fixing heterocytous cyanobacteria from this extreme and underexplored environment. A total of fourteen cyanobacterial strains were isolated. According to morphological examination they belong to the order Nostocales and to the subsections IV.I and IV.II, according to the International Code of Nomenclature for Algae, Fungi and Plants and the Bergey’s Manual of Systematic Bacteriology, respectively. Phylogenetic evaluation of their 16S rRNA gene sequences resulted in the formation of five clusters. Among them, one is clearly related to the genus Anabaenopsis whilst the remaining clusters may represent new genetic lineages. These novel sequences aid in the delimitation of problematic groups, especially those containing sequences belonging to mixed genera. The application of both morphologic and phylogenetic studies has proven to be an important tool in resolving problematic groups in cyanobacteria systematics. This strategy is essential in order to detect novel cyanobacteria genera from other tropical environments.

Multi-Drug Resistance of Bacterial Isolates among Dental Caries Patients

Background and Objectives: Dental caries is a well known major oral health problem in most developing countries which has multifactorial etiology caused by many facultatively anaerobes. S. mutans is the main pathogen associated with this disease. Recently Multi-Drug Resistant (MDR) species of S. mutans were identified from the dental caries patients against many commercial antibiotics. MDR is a natural phenomenon, posing a serious worldwide threat to public health. Several therapeutic agents are available to treat or prevent tooth decay, but still global burden of the disease with MDR are emerging. Therefore, the present study was designed for assessing the antibiotic sensitivity pattern of commercially available antibiotics.Material and Methods: This cross-sectional study was carried out by following Standard protocols of Bergey’s Manual of Systematic Bacteriology to isolate and identify the organism and further followed by antibiotic susceptibility test of bacterial isolates by disc diffusion method.Results: Streptococcus mutans (40%) was the most predominant to cause dental caries followed by S. aureus with 28.92. Gram positive isolates were found to be frequently resistant towards penicillin and tetracycline whereas Gram negative isolates were found to be Cotrimoxazole resistant.Conclusion: A high frequency of penicillin resistance in oral isolates and its co-resistance to erythromycin, tetracycline, gentamycin and amipicillin among the pateints was observed. The various awareness programmes should be facilitating the appropriate use of antibiotic to re-establish dominance over diseases must be implemented.Janaki Medical College Journal of Medical Sciences (2015) Vol. 3 (1):37-44