scholarly journals Metal Contaminants Occurrence and Microbial Diversity From the Perspectives of Dual Tolerance by the Bacterial Isolates Along Altitudinal Zonation of River Teesta – a Pristine River System in Eastern Himalayas

Author(s):  
Upashna Chettri ◽  
S R Joshi

Abstract The present study was conducted along River Teesta in Eastern Himalaya. Water and sediment samples were collected from six sampling points during the monsoon and winter seasons along the course of the river. The background information was collected by analysing physico-chemical parameters and the heavy metal concentrations. Culturable bacterial diversity using culture-based and molecular based 16S rRNA approaches characterized bacterial isolates to 5 major phyla, majority belonging Proteobacteria, Actinobacteria and Firmicutes followed by Bacteroidetes, Alpha-Proteobacteria, Beta-Proteobacteria, Gamma-Proteobacteria, Actinobacteria, Bacilli, Flavobacteriia, Deinococci, Sphingobacteriia and Cytophagia. The total of 245 characterized isolates belonged to 69 genera. Diversity indices were calculated for each site. There were variations in the community structure of culturable bacteria along the river stretch with some common and unique groups. Heavy metal tolerance and antibiotic resistance profiles showed some isolates to be tolerant to high levels of heavy metals and multiple antibiotic indicating a major concern. The antibiotic resistance diversified along the human impacted downstream sites. The present report on bacterial diversity and the associated metal and antibiotics tolerance is the first of its kind on Teesta river, the only major river system flowing through the state of Sikkim and parts of North Bengal.

2013 ◽  
Vol 7 (2) ◽  
pp. 130-136 ◽  
Author(s):  
Tewari Suman ◽  
W Ramteke Pramod ◽  
Tripathi Manikant ◽  
Kumar Shailendra ◽  
Kumar Garg Satyendra

2019 ◽  
Vol Volume 12 ◽  
pp. 1029-1033 ◽  
Author(s):  
Renata Galetti ◽  
Rafael Antonio Casarin Penha Filho ◽  
Joseane Cristina Ferreira ◽  
Alessandro M. Varani ◽  
Ana Lúcia Costa Darini

2016 ◽  
Vol 30 (1-2) ◽  
pp. 17-22 ◽  
Author(s):  
Tahmina Shammi ◽  
Sangita Ahmed

Pollution of the environment with toxic heavy metals is spreading throughout the world along with industrial progress. Removal of these toxic heavy metals by using bacteria has achieved growing attention in recent years. The present study focuses on isolation of lead and chromium tolerant Bacillus spp., from the Buriganga and the Shitalkhya, the two major rivers surrounding Dhaka. A total of 25 Bacillus spp. isolates tolerant to 50 ppm lead and chromium were preliminarily identified based on morphological and biochemical analysis. Further investigation revealed that all isolates were also able to grow at 1000 ppm lead and 400 ppm chromium, while tolerance to 1500 ppm lead and 500 ppm chromium was observed among 48% and 76% isolates, respectively. All isolates were also able to grow at 50 ppm copper and 50 ppm zinc, while 72% grew at 100 ppm copper. The heavy metal tolerant Bacillus spp were also multi drug resistant and showed resistance to Tetracycline (100%), Ceftazidime (100%), Ceftriaxone (100%), Ampicillin (28%) and Nalidixic acid (24%).Bangladesh J Microbiol, Volume 30, Number 1-2,June-Dec 2013, pp 17-22


Our Nature ◽  
1970 ◽  
Vol 7 (1) ◽  
pp. 203-206 ◽  
Author(s):  
M. Sharma ◽  
H.P. Thapaliya

Heavy metal resistant bacterial isolates from the effluent in a garment industry site were examined to assess their resistance towards multiple antibiotics. Heavy metal resistance property has been found to enhance the antibiotic resistance ability of microorganisms. Isolation of the heavy metal resistant organisms was done in media containing salts of heavy metals. Organisms were identified belonging to the genera Bacillus, Corynebacterium, Lactobacillus, Aeromonas and Enterococcus. Bacterial isolates were tested for their sensitivity to seven common antibiotics (penicillin, tetracycline, erythromycin, chloramphenicol, gentamicin, vancomycin and cotrimoxazole) using Kirby-Bauer technique. Isolates were found to be resistant to multiple antibiotics but all the isolates were sensitive to gentamicin. The data of our study indicates that metal pollution of the environment is the cause of heavy metal resistance isolates and hence antibiotic resistance.Key words: Heavy metal, effluent, antibiotics, resistance, Bacteria, pollution.DOI: 10.3126/on.v7i1.2572Our Nature (2009) 7:203-206  


2012 ◽  
Vol 30 (1) ◽  
pp. 58 ◽  
Author(s):  
M. P. Krishna ◽  
Rinoy Varghese ◽  
A. A. Mohamed Hatha

The development of multiple metal/antibiotic resistances among the bacterial population causes a potential risk to human health. Metal contamination in natural environments could have an important role in the maintenance and proliferation of antibiotic resistance. In the present study, a total of 46 heterotrophic bacterial isolates from metal contaminated soil were tested for their sensitivity to 10 widely used antibiotics such as ampicillin, erythromycin, gentamicin, nalidixic acid, penicillin, amikacin, lincomycin, novobiocin, vancomycin and tetracycline. Metal tolerant ability of these isolates against five heavy metals such as lead, zinc, copper, cadmium and nickel were also determined. The results revealed that most of the bacterial isolates were resistant to one or more heavy metals/ antibiotics against which they are tested. Tolerance to heavy metal showed the following pattern; lead > zinc > nickel > copper > cadmium. Resistance to ampicillin (73.91%), penicillin (60.8%), lincomycin (43.47%) and nalidixic acid (21.73%) were encountered frequently. None of the isolates were resistant to amikacin, while resistance to gentamicin and tetracycline were low (2.17%). Out of the 46 bacterial isolates, 36 isolates showed multiple metal and antibiotic resistances. Isolate LOC 10 showed significantly high tolerance (100-300�g/mL) to all the metals and was resistant to 6 antibiotics.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jerneja Zupančič ◽  
Martina Turk ◽  
Miha Črnigoj ◽  
Jerneja Ambrožič Avguštin ◽  
Nina Gunde-Cimerman

Abstract Background In modern lifestyles, people make their everyday tasks easier by using household appliances, for example dishwashers. Previous studies showed massive contamination of dishwasher rubber seals with fungi, thus bacterial community, able to survive under harsh conditions, remain undetermined. Methods Bacteria that colonise the extreme environment of household dishwasher rubber seals were investigated using cultivation-dependent and metagenomic approaches. All bacterial isolates were tested for resistance to seven selected antibiotics. Same time bacterial diversity of tap water, connected to the dishwashers was investigated. Results All 30 dishwashers investigated were colonised by various bacteria. Cultivation approaches resulted in 632 bacterial isolates in total, belonging to four phyla, eight classes, 40 genera and 74 species. The majority were Gram-positive, as solely Firmicutes (dominated by the Bacillus cereus group) and Actinobacteria. Gammaproteobacteria were primarily represented by Stenotrophomonas maltophilia, Pseudomonas aeruginosa and Escherichia coli. Metagenomic assessment of the bacterial biodiversity of the dishwasher rubber seals confirmed the predominance of Gram-positive bacteria, as primarily Actinobacteria, followed by Proteobacteria dominated by Gammaproteobacteria, and by pathogenic species such as Escherichia sp., Acinetobacter baumannii, Pseudomonas sp., Stenotrophomonas maltophilia, and Enterobacter sp.. Metagenomic assessment of bacterial biodiversity in the tap water connected to dishwashers revealed predominance of Gram-negative bacteria, in particular Proteobacteria, mainly represented by Tepidimonas sp.. Actinobacteria showed low numbers while no Firmicutes were detected in the tap water. The bacterial diversity of tap water was also lower, 23 genera compared to 39 genera on dishwasher rubber seals. Only 13 out of 49 genera identified by metagenomics approach was found in both environments, of those Gordonia was enriched while half of 13 genera were depleted in dishwashers compared to tap water. Conclusions These data indicate that colonisation of dishwasher rubber seals probably depends primarily on the bacterial input from the dirty vessels, and much less on the bacteria in the tap water. Based on the antibiotic resistance data, the dishwasher rubber seal bacterial isolates do not represent a serious threat for the spread of antibiotic resistance into the household environment. Nevertheless dishwashers cannot be ignored as potential sources of human infections, in particular for immuno-compromised individuals.


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