title: Antibiotic resistance pattern and plasmid profiling of thermotolerant Escherichia coli isolates in drinking water.
abstract: BACKGROUND
  Antibiotic resistant Escherichia coli is potential source of transmission of resistance to other water borne pathogens where plasmid borne resistance is most significant.
  
  
  METHODS
  Drinking water samples were collected from different water sources: that is to say- tap, well and spring from different places of Kathmandu where E. coli and thermotolerant E. coli were isolated using membrane filtration technique. Antibiotic susceptibility was determined using a modified Kirby Bauer disc diffusion method and thermotolerant E. coli isolates from tap water were subjected for plasmid profiling.
  
  
  RESULTS
  Type of water sources were not associated with the presence of coliform (P=0.155) and thermotolerant coliform (P=0.235) but the significant association was observed in thermotolerant coliform and thermotolerant E. coli for all sources tap (P=0.029), well (P=0.028), spring (P=0.05) but total coliform and E. coli association was found for well (P=0.01). All E. coli and thermotolerant E. coli isolates were susceptible to Ofloxacin, Chloramphenicol and Cotrimixazole. Resistance to Cefexime, Amikacin, Nalidixic acid, Amoxicillin, Tetracycline were 17 (54.8%), 9 (29%), 11 (35.5%), 25 (80.6%), 29 (93.5%) and 19 (57.6%), 12 (36.4%), 13 (39.4%), 31 (94%), 33 (100%) was observed in E. coli and thermotolerant E. coli respectively where 25 (75.8%) thermotolerant E. coli and 22 (70.9%) E. coli were observed with multiple drug resistance patterns. Single band of plasmid were observed in three MDRs and one non-MDR isolates and size varied from 2kb to >10kb. All Nalidixic acid resistant thermotolerant E. coli were found to harbor a plasmid.
  
  
  CONCLUSIONS
  Presence of plasmid in Nalidixic acid resistant thermotolerant E. coli heightens public health issue and the need of monitoring Quinolone resistance bacteria in environment.
authors.affiliation: Central Department of Microbiology, Tribhuvan University, Kritipur, Kathmandu, Nepal. princesubba05@gmail. com
authors.forename: P
authors.initials: P
authors.lastname: Subba
authors.forename: D R
authors.initials: DR
authors.lastname: Joshi
authors.forename: D R
authors.initials: DR
authors.lastname: Bhatta
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003430:Cross-Sectional Studies; D052978:Disk Diffusion Antimicrobial Tests; D060766:Drinking Water / Q000382:microbiology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006358:Hot Temperature; D009390:Nepal; D010957:Plasmids / Q000235:genetics; D014881:Water Supply / Q000592:standards
chemical_list: D000900:Anti-Bacterial Agents; D060766:Drinking Water