title: Multidrug resistant Vibrio cholerae O1 from clinical and environmental samples in Kathmandu city.
abstract: BACKGROUND
  Cholera, an infectious disease caused by Vibrio cholerae, is a major public health problem and is a particularly burden in developing countries including Nepal. Although the recent worldwide outbreaks of cholera have been due to V. cholerae El Tor, the classical biotypes are still predominant in Nepal. Serogroup O1 of the V. cholerae classical biotype was the primary cause of a cholera outbreak in Kathmandu in 2012. Thus, this study was designed to know serotypes and biotypes of V. cholerae strains causing recent outbreak with reference to drug resistant patterns. Moreover, we also report the toxigenic strains of V. cholerae from both environmental and clinical specimens by detecting the ctx gene.
  
  
  METHODS
  Twenty four V. cholerae (n = 22 from stool samples and n = 2 from water samples) isolated in this study were subjected to Serotyping and biotyping following the standard protocols as described previously. All of the isolates were tested for antimicrobial susceptibility patterns using the modified Kirby-Bauer disk diffusion method as recommended by CLSI guidelines. The screening of the ctx genes (ctxA2-B gene) were performed by PCR method using a pair of primers; C2F (5'-AGGTGTAAAATTCCTTGACGA-3') and C2R (5'-TCCTCAGGGTATCCTTCATC-3') to identify the toxigenic strains of V. cholerae.
  
  
  RESULTS
  Among twenty four V. cholerae isolates, 91.7% were clinical and 8.3% were from water samples. Higher rate of V. cholerae infection was found among adults of aged group 20-30 years. All isolates were serogroups O1 of the V. cholerae classical biotype and sub serotype, Ogawa. All isolates were resistant to ampicillin, nalidixic acid and cotrimoxazole. 90.9% were resistant to erythromycin however, tetracycline was found to be the most effective drug for the isolates. All isolates were multidrug resistant (MDR) and possessed a ctx gene of approximately 400 base pairs indicating the toxigenic strains.
  
  
  CONCLUSIONS
  Hundred percent strains of V. cholerae were MDR possessing a ctx gene. It suggests that toxigenic strains be identified and proper antibiotic susceptibility testing be conducted. This will allow effective empirical therapy to be used to treat and control cholera.
authors.affiliation: Research Laboratory for Biotechnology and Biochemistry (RLABB), Sanepa, Lalitpur, Nepal. upendrats@gmail.com.|Department of Microbiology, Kantipur College of Medical Science (KCMS), Sitapaila, KTM, Nepal. upendrats@gmail.com.
authors.forename: Upendra
authors.initials: U
authors.lastname: Thapa Shrestha
authors.affiliation: Department of Microbiology, Kantipur College of Medical Science (KCMS), Sitapaila, KTM, Nepal. adhinarinaba2004@yahoo.com.
authors.forename: Nabaraj
authors.initials: N
authors.lastname: Adhikari
authors.affiliation: Department of Microbiology, Kantipur College of Medical Science (KCMS), Sitapaila, KTM, Nepal. maharjan.rojina@gmail.com.
authors.forename: Rojina
authors.initials: R
authors.lastname: Maharjan
authors.affiliation: Central Department of Microbiology, Tribhuvan University, Kirtipur, KTM, Nepal. banjaramr@gmail.com.
authors.forename: Megha R
authors.initials: MR
authors.lastname: Banjara
authors.affiliation: Central Department of Microbiology, Tribhuvan University, Kirtipur, KTM, Nepal. rijalkomal@gmail.com.
authors.forename: Komal R
authors.initials: KR
authors.lastname: Rijal
authors.affiliation: Department of Microbiology, Kantipur College of Medical Science (KCMS), Sitapaila, KTM, Nepal. basnyatshitalraj@yahoo.com.
authors.forename: Shital R
authors.initials: SR
authors.lastname: Basnyat
authors.affiliation: Research Laboratory for Biotechnology and Biochemistry (RLABB), Sanepa, Lalitpur, Nepal. vpa@wlink.com.np.
authors.forename: Vishwanath P
authors.initials: VP
authors.lastname: Agrawal
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002771:Cholera / Q000453:epidemiology / Q000382:microbiology; D002772:Cholera Toxin / Q000235:genetics; D002947:Cities; D003428:Cross Infection / Q000235:genetics / Q000382:microbiology; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004777:Environment; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009390:Nepal / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D012703:Serotyping / Q000379:methods; D041241:Vibrio cholerae O1 / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002772:Cholera Toxin