scholarly journals Bacterial load and chemical pollution level of the River Buriganga, Dhaka, Bangladesh

1970 ◽  
Vol 38 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Mihir Lal Saha ◽  
Mahbubar Rahman Khan ◽  
Mohammad Ali ◽  
Sirajul Hoque

The River Buriganga is the life line of the Dhaka city and flanked in its southern side. The aerobic heterotrophic bacterial count of the River Buriganga was found to be in the range of 1.0 × 105 to 42.0 × 105cfu/ml while enteric bacterial counts on SS agar and MacConkey agar were 0.1 × 104 to 39.0 × 104cfu/ml and 0.3 × 103 to 3.5 × 104cfu/ml samples, respectively. Out of 74 isolates, 5 Gram-positive (22%) and 18 Gram-negative (78%) bacteria were randomly selected for detailed study. Bacillus was the dominant among the Gram-positive bacteria. Eighteen Gram-negative enteric isolates belonged to the genera Enterobacter (E. amnigenus and E. intermedium (44%), Alcaligenes (28%), Salmonella (17%), Escherichia (5.6%) and Plesiomonas) (5.6%). The NO3 -- N, NO2 -- N and phosphorus concentrations were found to be below the safety level from pollution point of view. BOD and COD values along with the presence of different bacteria clearly indicated that the River Buriganga was polluted with the organic, chemical and bacterial pollutants. Key words: Bacteria; Buriganga River; Enteric bacteria; Pollution; Bangladesh DOI: 10.3329/bjb.v38i1.5128 Bangladesh J. Bot. 38(1): 87-91, 2009 (June)

2017 ◽  
Vol 26 (1) ◽  
pp. 1-11
Author(s):  
Mihir Lal Saha ◽  
Md Atiq Mahbub ◽  
Tahsin Khan ◽  
M Moniruzzaman ◽  
Sirajul Hoque

The river Turag is the upper tributary of the river Buriganga in Bangladesh. Aerobic heterotrophic bacterial count of the river in nutrient agar (NA) and peptone yeast extract glucose (PYG) agar media ranged from 2.91 × 105 to 27.5 × 105 cfu/ml and from 1.09 × 105 to 19.3 × 105 cfu/ml, respectively. Enteric and related bacterial count on MacConkey agar was between 0.88 × 103 and 20.8 × 103 cfu/ml. Out of 91 isolated bacterial isolates, 30 were selected based on their distinctive colony morphology for detailed study. Among these, 16 were Grampositive (53%) and 14 were Gram-negative (47%). Bacillus was dominant among the Gram-positive isolates (69%). The remaining were Brochothrix thermosphacta (6%), Caryophanon sp. (19%) and Renibacterium salmoninarum (6%). Fourteen Gram-negative, enteric and related isolates were identified as Plesiomonas shigelloides (43%), Alcaligenes denitrificans (22%), E. coli (14%), Proteus (14%) and Citrobacter freundii (7%). Biological oxygen demand (BOD) and chemical oxygen demand (COD) values were about 9 and 5-fold higher than standard values whereas dissolved oxygen (DO) of the river was found to be six times less than the standard value. The maximum average TDS, conductivity and turbidity was recorded during the summer season as 441.75 ± 15.52 mg/l, 858.25 ± 19.57 μS/cm and 79.53 ± 6.49 NTU, respectively. Chemical contents viz. sulphate, chloride and fluoride were found to be satisfactory from pollution point of view. Both BOD and COD values along with the abundance of different heterotrophic and enteric bacteria clearly indicated that the river Turag was polluted with organic, chemical and bacterial pollutants. Dhaka Univ. J. Biol. Sci. 26(1): 1-11, 2017 (January)


2016 ◽  
Vol 29 (1) ◽  
pp. 11-15
Author(s):  
Md Abdul Karim ◽  
Rehena Nasrin Happy ◽  
Md Saifur Rasul ◽  
Sirajul Hoque

The Buriganga is one of the highly polluted rivers in Bangladesh. Most of the industries and factories of Dhaka are situated on the banks of the river Buriganga or very close to the river system. Substantial part of urban sewage of the Dhaka city is also disposed in the river Buriganga. The study was conducted to determine the pollution level of water of river Buriganga. Field investigation was started from May 2010 and sample collection was conducted in different seasons up to June 2011. Various water quality parameters such as pH, DO, BOD, COD, TDS, Conductivity, Alkalinity, NO2 --N, NO3 --N, NH4+-N and PO4 -, were determined for water of each sampling points to monitor the level of these parameters where it exceeds or remain within the permissible limit. DO concentration of water of river Buriganga was very low ranging between 0.04 and 2.25 mg/l. The aerobic heterotrophic bacterial count ranged between 1.0 × 107 and 2.0 × 108 cfu/100 ml. The highest count of enteric bacteria was noticed during the autumn that was 2.0 × 105 cfu/100 ml. BOD and COD values along with the presence of different species of bacteria clearly indicated that the water of the river Buriganga is highly polluted with the organic, chemical and bacterial pollutants.Bangladesh J Microbiol, Volume 29, Number 1, June 2012, pp 11-15


2013 ◽  
Vol 40 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Md Abdul Karim ◽  
Nazneen Akhter ◽  
Sirajul Hoque

Water samples were collected from four selected sites of the Gulshan lake during four different seasons. Four different media were used to study the aerobic heterotrophic, enteric and related bacterial abundance. Aerobic heterotrophic bacterial abundance ranged between 1×106 and 9×106 cfu/100 ml, while enteric and related bacterial abundance in SS agar, MacConkey agar and Cetrimide agar media ranged between 1×103 and 3×105 cfu/100 ml, between 1×104 and 1×107, and between 1×100 and 1.4×103 cfu/100 ml, respectively. Among 40 bacterial isolates 14 were selected out of which seven were Gram-positive and seven were Gramnegative. Among Gram-positive isolates, six were rod-shaped spore former belonging to Bacillus and Lactobacillus, while another one was coccoid in shape and under the genus Planococcus. Out of seven Gram-negative isolates, two were the members of Pseudomonas, remaining five were Morganella, Neisseria, Escherichia, Aeromonas and Enterobacter. Inorganic nutrients like NH4+-N, NO3+-N, NO2+-N and PO4+ values were found to be satisfactory from pollution point of view. The presence of different bacterial isolates indicate that the Gulshan lake water was polluted with chemical and bacterial pollutants. DOI: http://dx.doi.org/10.3329/bjz.v40i2.14309 Bangladesh J. Zool. 40(2): 165-173, 2012


2013 ◽  
Vol 38 (2) ◽  
pp. 155-161 ◽  
Author(s):  
Md Abdul Karim ◽  
Nazneen Akhter ◽  
Sirajul Hoque

Gulshan-Baridhara lake located in and around Gulshan, Banani and Baridhara, has always been Dhaka’s most exclusive residential area mainly because of the pristine lake. The lake is elongated in a north south direction and surrounded mainly by residential areas and some industrial units as well. To evaluate the pollution level of the sediment of the lake, samples were collected from 4 selected locations in 4 different seasons. Four different media were used to study the aerobic heterotrophic, enteric and related bacterial count. Aerobic heterotrophic bacterial count was in the range of 1.1 × 104 to 1.2 ×106 cfu/g in sediment sample, while enteric and related bacterial count in 3 different media (SS agar, MacConkey agar and Cetrimide agar) were 1×100 to 1.5×104 cfu/g, 1×100 to 6×104, and 1×100 to 1.1×103 cfu/g in sediment, respectively. Out of 23 bacterial isolates 18 were Gram-positive and 5 were Gram-negative. Among the Gram-positive, all were rod shaped spore former and under the genus Bacillus. Out of 5 Gram-negative isolates 2 were the member of Pseudomonas, remaining 3 strains were Escherichia, Aeromonas and Enterobacter. Total nitrogen and phosphorus level along with the presence of different bacterial strains clearly indicated that Gulshan lake sediment was polluted with the chemical and bacterial pollutants. DOI: http://dx.doi.org/10.3329/jasbs.v38i2.15596 J. Asiat. Soc. Bangladesh, Sci. 38(2): 155-161, December 2012


Author(s):  
Stefan Dörr ◽  
Ann-Kathrin Holland-Letz ◽  
Gregor Weisser ◽  
Apostolos Chatzitomaris ◽  
Ralf Lobmann

Introduction A diabetic foot infection (DFI) contributes to high mortality and morbidity in diabetics due to its often rapid progressive and intricately treatable infection. DFIs are usually a polymicrobial infection and characterizing the entire bacterial load is still challenging. Prompt and effective treatment of DFI is nevertheless mandatory to safe limbs and lives. It is therefore crucial to know the local pathogen spectrum and its antibiotic susceptibility. Methods and Material For a 12-month period, we investigated 353 individuals with infected diabetic foot ulcer, their bacterial diversity, and antimicrobial susceptibility at fist-time visit in a Diabetic Foot Care Center in southern Germany. Results Cultures yielded 888 species, most of them gram-positive cocci (primary Staphylococcus aureus). The gram-negative sector was mainly formed by Pseudomonas aeruginosa and Enterobacteriacae. Because the prevalence of multiresistant species was surprisingly low (0.9% of isolated strains), we suggest penicillins with β-lactamase inhibitor in case of gram-positive–dominated infection or piperacillin/tazobactam or rather carbapenems with equal efficacy when gram-negative species are involved.


2017 ◽  
Vol 43 (2) ◽  
pp. 173-180
Author(s):  
Md Abdul Karim ◽  
Nasrin Sultana

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


2018 ◽  
Vol 56 (8) ◽  
Author(s):  
Seon Young Kim ◽  
Yumi Park ◽  
Hyunjin Kim ◽  
Jimyung Kim ◽  
Sun Hoe Koo ◽  
...  

ABSTRACT Rapid screening of urinary tract infection is important to determine antibiotic treatment and reduce unnecessary urine culture. We evaluated the performance of the new flow cytometry-based UF-5000 automated urine analyzer (Sysmex, Kobe, Japan). A total of 1,430 urine samples from 1,226 patients were analyzed and compared to urine cultures to which a Previ Isola (bioMérieux, Marcy l'Etoile, France) system was applied. In total, 878 of 1,430 urine cultures (61.4%) produced ≥103 CFU/ml bacterial growth (309 with Gram-negative [GN] bacteria, 517 with Gram-positive [GP] bacteria, and 52 mixed cultures), with 336 samples (23.5%) presenting ≥105 CFU/ml bacterial growth. The ≥105 CFU/ml bacterial growth was detected by a ≥71 bacteria/μl UF-5000 bacterial count with 95% sensitivity and 84% specificity. Using a cutoff of <15 bacteria/μl to determine whether or not to culture, 50.9% of samples were below the cutoff, 94.8 and 99.5% of which presented <104 and <105 CFU/ml of bacterial growth, respectively. The bacterial discrimination performance of the UF-5000 for GN bacteria was superior to that for GP bacteria, and in ≥105 CFU/ml monobacterial samples, the sensitivity and specificity for reporting GN bacteria were 91.7 and 90.0%, respectively. In summary, UF-5000 demonstrated potential utility for the rapid screening of negative bacterial cultures. However, this utility is dependent on the patient population; cutoff optimizations must be performed for specific populations. In addition, UF-5000 presented improved performance in characterizing GP and GN bacteria, although the concurrence rates were not high enough to replace routine cultures.


2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Omeed Faghih ◽  
Zhongsheng Zhang ◽  
Ranae M. Ranade ◽  
J. Robert Gillespie ◽  
Sharon A. Creason ◽  
...  

ABSTRACT Antibiotic-resistant bacteria are widespread and pose a growing threat to human health. New antibiotics acting by novel mechanisms of action are needed to address this challenge. The bacterial methionyl-tRNA synthetase (MetRS) enzyme is essential for protein synthesis, and the type found in Gram-positive bacteria is substantially different from its counterpart found in the mammalian cytoplasm. Both previously published and new selective inhibitors were shown to be highly active against Gram-positive bacteria with MICs of ≤1.3 μg/ml against Staphylococcus, Enterococcus, and Streptococcus strains. Incorporation of radioactive precursors demonstrated that the mechanism of activity was due to the inhibition of protein synthesis. Little activity against Gram-negative bacteria was observed, consistent with the fact that Gram-negative bacterial species contain a different type of MetRS enzyme. The ratio of the MIC to the minimum bactericidal concentration (MBC) was consistent with a bacteriostatic mechanism. The level of protein binding of the compounds was high (>95%), and this translated to a substantial increase in MICs when the compounds were tested in the presence of serum. Despite this, the compounds were very active when they were tested in a Staphylococcus aureus murine thigh infection model. Compounds 1717 and 2144, given by oral gavage, resulted in 3- to 4-log decreases in the bacterial load compared to that in vehicle-treated mice, which was comparable to the results observed with the comparator drugs, vancomycin and linezolid. In summary, the research describes MetRS inhibitors with oral bioavailability that represent a class of compounds acting by a novel mechanism with excellent potential for clinical development.


2016 ◽  
Vol 60 (8) ◽  
pp. 5001-5005 ◽  
Author(s):  
Marguerite L. Monogue ◽  
Abrar K. Thabit ◽  
Yukihiro Hamada ◽  
David P. Nicolau

ABSTRACTMembers of the tetracycline class are frequently classified as bacteriostatic. However, recent findings have demonstrated an improved antibacterial killing profile, often achieving ≥3 log10bacterial count reduction, when such antibiotics have been given for periods longer than 24 h. We aimed to study this effect with eravacycline, a novel fluorocycline, given in an immunocompetent murine thigh infection model over 72 h against two methicillin-resistantStaphylococcus aureus(MRSA) isolates (eravacycline MICs = 0.03 and 0.25 μg/ml) and threeEnterobacteriaceaeisolates (eravacycline MICs = 0.125 to 0.25 μg/ml). A humanized eravacycline regimen, 2.5 mg/kg of body weight given intravenously (i.v.) every 12 h (q12h), demonstrated progressively enhanced activity over the 72-h study period. A cumulative dose response in which bacterial density was reduced by more than 3 log10CFU at 72 h was noted over the study period in the two Gram-positive isolates, and eravacycline performed similarly to comparator antibiotics (tigecycline, linezolid, and vancomycin). A cumulative dose response with eravacycline and comparators (tigecycline and meropenem) over the study period was also observed in the Gram-negative isolates, although more variability in bacterial killing was observed for all antibacterial agents. Overall, a bacterial count reduction of ≥3 log was achieved in one of the three isolates with both eravacycline and tigecycline, while meropenem achieved a similar endpoint against two of the three isolates. Bactericidal activity is typically definedin vitroover 24 h; however, extended regimen studiesin vivomay demonstrate an improved correlation with clinical outcomes by better identification of antimicrobial effects.


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