The Antimicrobial Activity of Quercus Infectoria Extracts Against Bacteria Isolated from Wounds Infection

Bacteria that cause wound infections were isolated and diagnosed from patients, who were hospitalized at the Martyr Al-Sadr Hospital from October 2019 to April 2020. Antibacterial effect of Quercus infectoria extract (aqueous and alcoholic) on the isolated bacteria has been studied. The results showed that the alcoholic extract has a higher antibacterial effect than the aqueous extract against Gram-positive bacteria like Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus saprophyticus except Micrococcus roseus, which the effect of aqueous extract was higher than alcoholic extract, whereas aqueous and alcoholic extracts showed the same effect against Streptococcus sp.. The alcoholic extract has higher antibacterial effect than the aqueous extract against Gram-negative bacteria (Escherichia coli, Pseudomonas sp., Enterococcus faecalis, Shigella dysnteriae, Enterobacter sakazkii, citrobcter freundii and Alcaligenes faecalis) except proteus sp., which the aqueous extract was higher than alcoholic extract.

Compatibility and formulation of diesel degrading consortia using bacteria isolated from contaminated soil

Soil contamination with diesel spillage is an increasing environmental challenge that damages living ecosystems. Efficiency of single bacterium in degrading diesel oil pollutants is faced with slow performance limitation. Therefore, the use of consortia is shown to be better, due to synergism, multi-enzymatic activity and potential for diversified catabolic functionalities. This study is aimed at formulating effective bacterial consortia that can degrade diesel in polluted environments. Four diesel degrading bacteria as Bacillus subtilis, Staphylococcus aureus, Micrococcus roseus and Rhodococcus specie were isolated and used for consortia formulation. Purity testing was performed on the isolates prior to consortia formulation, before their compatibility was tested by cross-spreading them on nutrient agar. Consortia formulation was made using Bacteria resting cells in Phosphate Buffer Saline based on compatibility testing and mathematical permutations. For on their ability to survive diesel on Bushnell-Haas Agar (BHA), consortia 2, 9 and 11 showed the best results among which consortium 11 was chosen as the best, considering growths on the medium within a 72 hrs period. The growth of the organisms before consortia formulation and after was also evaluated, which suggest that the consortium perform better than individual strains. Analysis of Variance showed significant statistical differences (p<0.05) between constituents of consortia, and diesel degradation on 2% (v/v) BHA. The degradation performances of the various consortia on BHA were furthermore separated by Duncan’s Multiple Range Test. The colony counts obtained indicate that degradation was performed better by the consortia than individual strains. The findings of the study contribute towards illuminating inter-microbial relationships and microbial ecology especially within groups of diesel degrading bacteria. Further studies are imperative, to maximally harness the potentials of these bacteria for applications in large scale diesel biodegradation. Key Words: Consortia, Diesel, Bacterial Biodegradation, Haemocytometry.

CORRELATION ANALYSIS BETWEEN INDOOR AIRBORNE BACTERIAL LOAD AND OCCUPANT DENSITY IN HOSPITAL INDOOR AIR

A study of the quantity and types of airborne bacteria and its correlation with human presence was conducted. Air samples were collected from different units for three days and three sessions (morning, afternoon and evening) for the enumeration and identification of bacterial isolates. Walk-through exercise was also conducted prior to every sampling to gather information on the number of occupants present, activities going on, and room characteristics. Isolation study revealed higher bacterial load in the afternoon and evening sessions; with Male Ward and Operating Theatre recording the highest and lowest bacterial loads respectively, as compared to the morning session that was done immediately after cleaning and before influx of people. The Spearman’s Correlation Coefficient showed a positively direct linear correlation between the bacterial load and occupant population irrespective of the three sessions (r = 0.84, 0.88 and 0.93). Identification study showed that the isolates are representatives of normal microflora of the skin, respiratory and gastro-intestinal tracts which includes the following; Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus roseus, Klebsiella pneumoniae, Proteus mirabilis, Bacillus subtilis, Aspergillus, Penicillium, Mucor, Candida and Fusarium species. The study presents evidence of increased concentration of indoor airborne bacteria due to human presence, movement and activities.

Haloarchaeal Carotenoids: Healthy Novel Compounds from Extreme Environments

Haloarchaea are halophilic microorganisms belonging to the archaea domain that inhabit salty environments (mainly soils and water) all over the world. Most of the genera included in this group can produce carotenoids at significant concentrations (even wild-type strains). The major carotenoid produced by the cells is bacterioruberin (and its derivatives), which is only produced by this kind of microbes and few bacteria, like Micrococcus roseus. Nevertheless, the understanding of carotenoid metabolism in haloarchaea, its regulation, and the roles of carotenoid derivatives in this group of extreme microorganisms remains mostly unrevealed. Besides, potential biotechnological uses of haloarchaeal pigments are poorly explored. This work summarises what it has been described so far about carotenoids from haloarchaea and their production at mid- and large-scale, paying special attention to the most recent findings on the potential uses of haloarchaeal pigments in biomedicine.

Diversity and Antibiotic Susceptibility of Bacteria in Water of Hotel Restaurants in Dhaka City

Present study was conducted to determine the microbiological status of water from dispensers in different roadside hotel and restaurants of Dhaka city. Samples were collected from seven hotel and restaurants. Aerobic heterotrophic bacterial count ranged between 1.5 × 10 and 8.8 × 103 cfu/ml. Enteric and related bacterial abundance in MacConkey, SS and Cetrimide agar media ranged from 0 to 4.9 × 106, 0 to 2.1 × 105 and 0 to 1.2 × 106cfu/ml, respectively. In total, 28 bacterial isolates were obtained during the study period. Among them, 15 were heterotrophic isolates and 13 were enteric and related bacteria. Among 15 aerobic heterotrophic isolates, 11 were gram positive and five were gram negative. Out of 11 gram positive isolates, 7 belonged to the genus Bacillus viz. B. circulans, B. subtilis, B. stearothermophilus, B. brevis and B. cereus and one to coccus viz. Micrococcus roseus. The other gram positive species were Kurtia gibsonii, Auriobacterium liguefaciens and Curtobacterium luteum. Four gram negative isolates were Neisseria elongate sub. spp. glycolytica, Plesiomonas shigelloides, Pseudomonas fluorescens biovar 1, Pseudomonas aeruginosa. All 13 enteric and related isolates were gram negative, short rod; and non-spore formers and belonged to the genera Escherichia, Klebsiella, Shigella and Pseudomonas. Among all isolates, two were resistant and six were susceptible to all five antibiotics. Asiat. Soc. Bangladesh, Sci. 43(2): 173-180, December 2017

Bioaccumulation of Heavy Metals using Selected Organisms Isolated from Electronic Waste Dumpsite of two South-Western States in Nigeria

Heavy metals from electronic wastes can accumulate to alarming concentrations in soils, causing significant detrimental impacts on human life and the environment. Bioaccumulation of heavy metals by bacteria and fungi has been a major focus of most bioremediation studies owing to the excellent metal-binding properties. The current study was conducted to isolate the most promising Zn, Cu and Pb tolerant microorganisms from contaminated soils, and to assess their metal accumulating abilities. Bacillus licheniformis, B. polymyxa, Pseudomonas aeruginosa, Micrococcus roseus, Aspergillus niger and A. flavus were selected for the bioaccumulation study, based on their known tolerance to heavy metals. Bacillus licheniformis was most efficient in the removal of Cu (71.3 %) and Pb (70.1 %). Pb accumulation for Aspergillus flavus was 65.76 %. Zn accumulation for Pseudomonas aeruginosa and Aspergillus niger were 74.1 % and 78.3 %, respectively. This study concluded that all these microorganisms have potential for bioremediating soil environments contaminated with heavy metals.

Βacterial flora isolated from the oesophageal bulb of the olive fruit fly Dacus oleae (Gmelin)

In a study of the bacterial flora occurring in the adults of the olive fruit fly, Dacus oleae (Gmelin) (Diptera: Tephritidae), oesophageal diverticulum, a total of 28 strains were obtained. Six of them were Gram – negative and identified as Pseudomonas niendocina, Morarella nonliquefasciens (2), Alcaligenes sp., Enterobacter cloacae (2) and 22 Gram-positive classified as Kurthia sp., Staphylococcus subgroup VI, Micrococcus roseus, Bacillus pumilus, B. licheniformis (3) and B. subtilis(15). None of the above bacteria are strictly fixed and constantly present in the oesophageal diverticulum, suggesting that the bacterial flora associated with D. oleae depends on environmental factors, and could be used as a nutrient source for the insect apart from its possible other symbiotic role.