title: Prevalence and antimicrobial resistance of Salmonella isolated from lactating cows and in contact humans in dairy farms of Addis Ababa: a cross sectional study.
abstract: BACKGROUND
  Salmonella are the major pathogenic bacteria in humans as well as in animals. Salmonella species are leading causes of acute gastroenteritis in several countries and salmonellosis remains an important public health problem worldwide, particularly in the developing countries. The situation is more aggravated by the ever increasing rate of antimicrobial resistance strains. Cattle have been implicated as a source of human infection with antimicrobial resistant Salmonella through direct contact with livestock and through the isolation of antimicrobial resistant Salmonella from raw milk, cheddar cheese, and hamburger meat traced to dairy farms. Despiite the presence of many studies on the prevalence and antimicrobial susceptibility pattern of Salmonella in Ethiopia, nothing has been said on the degree of the situation among apparently healthy lactating cows and in contact humans. Hence this study was conducted to determine the prevalence and antimicrobial resistance pattern of Salmonella isolates from lactating cows and in contact humans in dairy farms of Addis Ababa.
  
  
  METHODS
  a cross sectional study was conducted in Addis Ababa by collecting milk and faecal samples from lactating cows and stool samples from humans working in dairy farms. Samples were pre-enriched in buffered peptone water followed by selective enrichment using selenite cysteine and Rapaport-Vassilidis broths. Isolation and identification was made by inoculating the selectively enriched sample on to Xylose Lysine Deoxycholate agar followed by confirmation of presumptive colonies using different biochemical tests. The Kibry Bauer disk diffusion method was used for antimicrobial sensitivity testing.
  
  
  RESULTS
  10.7% (21/195) of cows and 13.6% (3/22) of the human subjects sheded Salmonella. 83% resistance to two or more antimicrobials and 100% resistance to ampicillin were observed. Most of the isolates were relatively sensitive to ciprofloxacin, cotrimoxazole, and chloramphenicol.
  
  
  CONCLUSIONS
  High proportion of Salmonella isolates developed resistance to the commonly prescribed antimicrobials and this may be a considerable risk in the treatment of clinical cases. So, wise use of antimicrobials must be practiced to combat the ever increasing situation of antimicrobial resistance.
authors.affiliation: University of Gondar, College of Medicine and Health Science, Department of Medical Laboratory Science, P O Box 196, Gondar, Ethiopia. zelalemaddis@ymail.com
authors.forename: Zelalem
authors.initials: Z
authors.lastname: Addis
authors.forename: Nigatu
authors.initials: N
authors.lastname: Kebede
authors.forename: Zufan
authors.initials: Z
authors.lastname: Worku
authors.forename: Haile
authors.initials: H
authors.lastname: Gezahegn
authors.forename: Alehegne
authors.initials: A
authors.lastname: Yirsaw
authors.forename: Tesfu
authors.initials: T
authors.lastname: Kassa
mesh_terms: D000383:Agriculture; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001431:Bacteriological Techniques / Q000379:methods; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000382:microbiology; D003430:Cross-Sectional Studies; D024881:Drug Resistance, Bacterial; D005002:Ethiopia / Q000453:epidemiology; D005243:Feces / Q000382:microbiology; D006801:Humans; D008892:Milk / Q000382:microbiology; D015995:Prevalence; D012475:Salmonella / Q000187:drug effects* / Q000302:isolation & purification; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology; D012481:Salmonella Infections, Animal / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents