Screening and Characterization of Bacillus Strains Producing Highly Thermostable Amylase from Various Hot Springs of Algeria

HIGHLIGHTS Screening extremophile Bacillus strains from various Hot Springs Characterization Of Bacillus Strains Producing Highly Thermostable Amylase Genetic identification of the best strains

Abstract Currently thermostable Amylase represents a broad biotechnological interest and desired by a various industries. In this study, forty-six bacterial strains belonging to the genus Bacillus were isolated from various hot springs in the North West of Algeria based on their ability to degrade starch and produce amylase in Starch Agar medium. The majority of isolates showed a positive amylolytic activity. In order to select the most thermostables amylase the effect of temperature on enzymes was estimated, therefore the study of amylase thermostability was culminated by the selection of Four Strains having an interesting optimum of activity and range of stability, reaching 75 °C for the strains HBH1-2, HBH1-3, HBH3-1and 85 °C for the strain HC-2, This indicates that the Enzyme produced by retained strains have optimum activity at high temperature. The identity of the selected strains was established on the basis of the morphological, biochemical characteristics and phylogenetic position as determined by 16S Ribosomal DNA gene sequencing. The whole strains belonged to the genus Bacillus and their phylogeny were also reported in this study.

Phylogeny and Detection of blaTEM, blaSHV, blaCTX-M Genes in Escherichia coli Isolates from Patients with Urinary Tract Infections in Taif Hospitals, Saudi Arabia

Background: Urinary tract infections (UTIs) represent one of the most common diseases that are encountered in clinical practice and are caused mainly by Escherichia coli (E. coli). Aims: The objectives of this study were to identify and compare the blaTEM, blaSHV and blaCTX-M as marker of beta-lactamase genes in E. coli strains isolated from patients with UTIs collecting from King Abdul-Aziz hospital in Taif region, Saudi Arabia. Study Design: In vitro experimental and molecular study. Place and Duration of Study: Genetic engineering and biotechnology unit, Taif University, from September, 2016 to November, 2017. Methodology: Beta-lactame antibiotics are prescribed in most infectious disease including UTIs. Twenty one isolates identified as E. coli using microbial identification and confirmed by 16S rDNA. Results: These isolates were susceptible to Imipenem (100%), Ampicillin (90%) and Cefoxitin, but resistant to Cefepime (38%). Existance of selected bla-genes (blaTEM, blaSHV and blaCTX-M) were detected in the 21 isolates by PCR. Moreover, phylogeny tree was drawn based on 16S rDNA sequence. The results of this study show significant differences in susceptibility to different beta-lactam antibiotics among the bla-genes in E. coli isolates. Conclusion: Therefore, our findings instead of our data provide some new epidemiological information about the clonal nature of E. coli isolated from patients with UTIs in Taif region, KSA.

Nocardia veterana: disseminated infection with urinary tract infection

Nocardia spp. are a group of aerobic actinomycetes widely distributed in soil, and associated with severe opportunistic infections, essentially pulmonary infections. We report the first case of disseminated infection associated with urinary tract infection caused by Nocardia veterana. The diagnosis was difficult; despite the presence of pulmonary nodules, the lung biopsies remained negative while only one aerobic blood culture and the urine culture were positive for N. veterana, identified after a 16S rDNA gene sequence analysis. Few cases of clinical importance due to N. veterana have been published since its characterization. The bacteriological diagnosis of nocardiosis can be difficult to establish because of the delayed growth and the specific techniques that are required. This case illustrates the necessity of performing specific investigations in immunocompromised patients who present with infectious disease because the severity of this infection requires early diagnosis and quick initiation of appropriate antibiotic therapy.

Partial denture metal framework may harbor potentially pathogenic bacteria

PURPOSE: The aim of this study was to characterize and compare bacterial diversity on the removable partial denture (RPD) framework over time. MATERIALS AND METHODS: This descriptive pilot study included five women who were rehabilitated with free-end mandibular RPD. The biofilm on T-bar clasps were collected 1 week (t1) and 4 months (t2) after the RPD was inserted (t0). Bacterial 16S rDNA was extracted and PCR amplified. Amplicons were cloned; clones were submitted to cycle sequencing, and sequences were compared with GenBank (98% similarity). RESULTS: A total of 180 sequences with more than 499 bp were obtained. Two phylogenetic trees with 84 (t1) and 96 (t2) clones represented the bacteria biofilm at the RPD. About 93% of the obtained phylotypes fell into 25 known species for t1 and 17 for t2, which were grouped in 5 phyla: Firmicutes (t1=82%; t2=60%), Actinobacteria (t1=5%; t2=10%), Bacteroidetes (t1=2%; t2=6%), Proteobacteria (t1=10%; t2=15%) and Fusobacteria (t1=1%; t2=8%). The libraries also include 3 novel phylotypes for t1 and 11 for t2. Library t2 differs from t1 (P=.004); t1 is a subset of the t2 (P=.052). Periodontal pathogens, such as F. nucleatum, were more prevalent in t2. CONCLUSION: The biofilm composition of the RPD metal clasps changed along time after RPD wearing. The RPD framework may act as a reservoir for potentially pathogenic bacteria and the RPD wearers may benefit from regular follow-up visits and strategies on prosthesis-related oral health instructions.

Identification of Lactobacillus plantarum, Lactobacillus pentosus and Lactobacillus fermentum from honey stomach of honeybee

This study aimed to isolate and identify Lactobacillus in the honey stomach of honeybee Apis dorsata. Samples of honeybee were collected from A. dorsata colonies in different bee trees and Lactobacillus bacteria isolated from honey stomachs. Ninety two isolates were Gram-stained and tested for catalase reaction. By using bacterial universal primers, the 16S rDNA gene from DNA of bacterial colonies amplified with polymerase chain reaction (PCR). Forty-nine bacterial 16S rDNA gene were sequenced and entrusted in GenBank. Phylogenetic analysis showed they were different phylotypes of Lactobacillus. Two of them were most closely relevant to the previously described species Lactobacillus plantarum. Other two phylotypes were identified to be closely related to Lactobacillus pentosus. However, only one phylotype was found to be distantly linked to the Lactobacillus fermentum. The outcomes of the present study indicated that L. plantarum, L. pentosus, and L. fermentum were the dominant lactobacilli in the honey stomach of honeybee A. dorsata collected during the dry season from Malaysia forest area - specifically "Melaleuca in Terengganu".

Microbial diversity of soils on the banks of the Solimões and Negro rivers, state of Amazonas, Brazil

Analysis of bacterial diversity in soils along the banks of the Solimões and Negro rivers, state of Amazonas, Brazil, was by partial sequencing of the genes codifying the rDNA16S region. Diversity of operational taxonomic units (OTU) and of the divergent sequences obtained were applied in comparative analysis of microbiological diversity in the two environments, based on richness estimators and OTU diversity indices. The higher OTU diversity in the Solimões was based on the higher number of parameters that evoke this. The interaction between the nucleotide sequences of bacteria inhabiting the two riverine environments indicated that the two microrganism communities are similar in composition.