scholarly journals Tracking of chloramphenicol, erythromycin, and sulfamethoxazole antibiotic-resistant bacteria from untreated wastewater effluents to receiving river

2019 ◽  
Vol 6 (2) ◽  
pp. 89-96 ◽  
Author(s):  
Rahim Aali ◽  
Sepideh Baragh ◽  
Esrafil Asgari ◽  
Reza Fouladi Fard ◽  
Hassan Izanloo ◽  
...  

Background: The aim of this study was to investigate the frequency and type of bacteria resistant to chloramphenicol (CHL), erythromycin (E), and sulfamethoxazole (SXT) antibiotics from untreated wastewater effluents to receiving river. Methods: In total, 32 samples were taken from eight sites located in the raw wastewater to the downstream of the receiving Ghotor river in Khoy city. Resistant microorganisms were studied through modified HPC method and CLSI standards. Different and specific colonies were selected and re-cultured in R2A culture medium and enough colonies were used for DNA extraction. Bacterial 16sr RNA target gene was amplified and sequenced. Pseudomonas sp., Comamonas sp., and Thiobacillus sp. were predominant bacterial species identified in water samples. Also, antibiotic-resistant genes (ARGs) including sul1, ermB, and cmlA1 were tracked by PCR. Results: The average total number of antibiotic-resistant bacteria (ARB) increased in the downstream (2.4×102 to 2.6×104 CFU/100 mL). The comparison of the results related to the river’s upstream and downstream also indicated a significant difference between ARB and ARGs contents (P<0.05). The average number of bacteria resistant to SXT, E, and CHL antibiotics was obtained to be 2.3×104 , 2.3×104 , and 3.4×104 CFU/mL, respectively. Finally, the evaluation of water revealed that only the aeration lagoon was able to decline the number of CHL-resistant bacteria (88.9%) while this process increased the number of SXT- (51%) and E- (16%) resistant bacteria. The lowest and highest percentages of the identified genes were related to ermB (12.5%) and sul1 (81.25%), respectively. Conclusion: According to the results, wastewaters play an important role in releasing ARB and their antibiotic resistance genes to downstream of Ghotor rivers in Khoy city.

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 684
Author(s):  
Sofia Svebrant ◽  
Robert Spörndly ◽  
Richard H. Lindberg ◽  
Therese Olsen Sköldstam ◽  
Jim Larsson ◽  
...  

Hospital sewage constitutes an important point source for antibiotics and antibiotic-resistant bacteria due to the high antibiotic use. Antibiotic resistance can develop and cause problems in sewage systems within hospitals and municipal wastewater treatment plants, thus, interventions to treat hospital sewage on-site are important. Ozonation has proven effective in treating relatively clean wastewater, but the effect on untreated wastewater is unclear. Therefore, we piloted implementation of ozonation to treat wastewater in a tertiary hospital in Uppsala, Sweden. We measured active pharmaceutical ingredients (APIs) using liquid chromatography-mass spectrometry and antibiotic-resistant Enterobacteriaceae using selective culturing pre- and post-ozonation. Comparing low (1 m3/h) and high (2 m3/h) flow, we obtained a ‘dose-dependent’ effect of API reduction (significant reduction of 12/29 APIs using low and 2/29 APIs using high flow, and a mean reduction of antibiotics of 41% using low vs. 6% using high flow, 25% vs. 6% for all APIs). There was no significant difference in the amount of antibiotic-resistant Enterobacteiaceae pre- and post-ozonation. Our results demonstrate that ozonation of untreated wastewater can reduce API content. However, due to the moderate API decrease and numerous practical challenges in the on-site setting, this specific ozonation system is not suitable to implement at full scale in our hospital.


2020 ◽  
Vol 13 (2) ◽  
pp. 266-274 ◽  
Author(s):  
Sharmin Akter ◽  
Abdullah Al Momen Sabuj ◽  
Zobayda Farzana Haque ◽  
Md. Tanvir Rahman ◽  
Md. Abdul Kafi ◽  
...  

Background and Aim: Houseflies (Musca domestica) are synanthropic insects which serve as biological or mechanical vectors for spreading multidrug-resistant bacteria responsible for many infectious diseases. This study aimed to detect antibiotic-resistant bacteria from houseflies, and to examine their resistance genes. Materials and Methods: A total of 140 houseflies were captured using sterile nylon net from seven places of Mymensingh city, Bangladesh. Immediately after collection, flies were transferred to a sterile zipper bag and brought to microbiology laboratory within 1 h. Three bacterial species were isolated from houseflies, based on cultural and molecular tests. After that, the isolates were subjected to antimicrobial susceptibility testing against commonly used antibiotics, by the disk diffusion method. Finally, the detection of antibiotic resistance genes tetA, tetB, mcr-3, mecA, and mecC was performed by a polymerase chain reaction. Results: The most common isolates were Staphylococcus aureus (78.6%), Salmonella spp., (66.4%), and Escherichia coli (51.4%). These species of bacteria were recovered from 78.3% of isolates from the Mymensingh Medical College Hospital areas. Most of the isolates of the three bacterial species were resistant to erythromycin, tetracycline, penicillin and amoxicillin and were sensitive to ciprofloxacin, ceftriaxone, chloramphenicol, gentamicin, and azithromycin. Five antibiotic resistance genes of three bacteria were detected: tetA, tetB, mcr-3, and mecA were found in 37%, 20%, 20%, and 14% isolates, respectively, and no isolates were positive for mecC gene. Conclusion: S. aureus, Salmonella spp., and E. coli with genetically-mediated multiple antibiotic resistance are carried in houseflies in the Mymensingh region. Flies may, therefore, represent an important means of transmission of these antibiotic-resistant bacteria, with consequent risks to human and animal health.


Antibiotics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 575
Author(s):  
Emi Nishimura ◽  
Masateru Nishiyama ◽  
Kei Nukazawa ◽  
Yoshihiro Suzuki

Information on the actual existence of antibiotic-resistant bacteria in rivers where sewage, urban wastewater, and livestock wastewater do not load is essential to prevent the spread of antibiotic-resistant bacteria in water environments. This study compared the antibiotic resistance profile of Escherichia coli upstream and downstream of human habitation. The survey was conducted in the summer, winter, and spring seasons. Resistance to one or more antibiotics at upstream and downstream sites was on average 18% and 20%, respectively, and no significant difference was observed between the survey sites. The resistance rates at the upstream site (total of 98 isolated strains) to each antibiotic were cefazolin 17%, tetracycline 12%, and ampicillin 8%, in descending order. Conversely, for the downstream site (total of 89 isolated strains), the rates were ampicillin 16%, cefazolin 16%, and tetracycline 1% in descending order. The resistance rate of tetracycline in the downstream site was significantly lower than that of the upstream site. Furthermore, phylogenetic analysis revealed that many strains showed different resistance profiles even in the same cluster of the Pulsed-Field Gel Electrophoresis (PFGE) pattern. Moreover, the resistance profiles differed in the same cluster of the upstream and the downstream sites. In flowing from the upstream to the downstream site, it is plausible that E. coli transmitted or lacked the antibiotic resistance gene.


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