title: In vitro algicidal effect of guanidine on Prototheca zopfii genotype 2 strains isolated from clinical and subclinical bovine mastitis.
abstract: Prototheca species have increasingly been reported to be opportunistic pathogens that cause mastitis in dairy herds, and it poses an emergent problem because at present, there are no effective therapies for the treatment of protothecal mastitis. This study investigated the in vitro algicidal effect of guanidine on 75 Prototheca zopfii genotype 2 strains isolated from 75 cases of clinical and subclinical bovine mastitis. All strains were susceptible to guanidine in vitro with minimal algaecide concentrations ranging from 0·001 to 0·035%. Guanidine is known to have a high microbicidal effect and is considered to be a new generation microbicidal compound. It is not toxic to human mucous membranes and conjunctivas at low concentrations and has been used as a disinfectant in swimming pools and as an antiseptic for human wounds. The algicidal action of guanidine at low concentrations indicates that it could be an alternative disinfectant or antiseptic for cleaning of the dairy environment and milking equipment, in pre- and postdipping solutions, in the chemical dry therapy of bovine teats and even in the intramammary therapy of P. zopfii infections. This is the first report of the in vitro algicidal effect of guanidine on P. zopfii strains of animal origin.
  
  
  CONCLUSIONS
  Prototheca zopfii genotype 2 is an opportunistic pathogen of bovine mastitis. To date, no effective therapies against protothecal mastitis have been developed. The in vitro algicidal effect of guanidine on 75 P. zopfii genotype 2 strains isolated from cows revealed that all of the isolates were susceptible to the compound at low concentrations, which indicates that guanidine may be used as an antiseptic/disinfectant for dairy milking equipment, in pre- and postdipping solutions, and as a chemical dry therapy or an intramammary therapy. This study describes the in vitro algicidal effect of guanidine on P. zopfii for the first time.
authors.affiliation: Department of Veterinary Hygiene and Public Health, UNESP-São Paulo State University, Botucatu, SP, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Alves
authors.affiliation: Institute of Agricultural Biology and Biotechnology, National Research Council, Lodi, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Capra
authors.affiliation: Institute of Sciences of Food Production, National Research Council, Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Morandi
authors.affiliation: Institute of Agricultural Biology and Biotechnology, National Research Council, Lodi, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Cremonesi
authors.affiliation: Department of Veterinary Hygiene and Public Health, UNESP-São Paulo State University, Botucatu, SP, Brazil.
authors.forename: J C F
authors.initials: JCF
authors.lastname: Pantoja
authors.affiliation: Department of Veterinary Hygiene and Public Health, UNESP-São Paulo State University, Botucatu, SP, Brazil.
authors.forename: H
authors.initials: H
authors.lastname: Langoni
authors.affiliation: Department of Preventive Veterinary Medicine, Federal University of Santa Maria, Santa Maria, RS, Brazil.
authors.forename: A P C
authors.initials: APC
authors.lastname: de Vargas
authors.affiliation: Federal University of São Francisco Valley, PE, Brazil.
authors.forename: M M
authors.initials: MM
authors.lastname: da Costa
authors.affiliation: Department of Applied Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw, Warsaw, Poland.
authors.forename: T
authors.initials: T
authors.lastname: Jagielski
authors.affiliation: Department of Veterinary Hygiene and Public Health, UNESP-São Paulo State University, Botucatu, SP, Brazil.
authors.forename: C A D
authors.initials: CAD
authors.lastname: Bolaños
authors.affiliation: Department of Veterinary Hygiene and Public Health, UNESP-São Paulo State University, Botucatu, SP, Brazil.
authors.forename: S T
authors.initials: ST
authors.lastname: Guerra
authors.affiliation: Department of Veterinary Hygiene and Public Health, UNESP-São Paulo State University, Botucatu, SP, Brazil.
authors.forename: M G
authors.initials: MG
authors.lastname: Ribeiro
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D000891:Anti-Infective Agents, Local / Q000494:pharmacology; D002417:Cattle; D003612:Dairying; D004202:Disinfectants / Q000494:pharmacology; D005260:Female; D005838:Genotype; D019791:Guanidine / Q000494:pharmacology*; D006801:Humans; D008414:Mastitis, Bovine / Q000188:drug therapy / Q000453:epidemiology*; D017720:Molecular Epidemiology; D011525:Prototheca / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000890:Anti-Infective Agents; D000891:Anti-Infective Agents, Local; D004202:Disinfectants; D019791:Guanidine
keywords: algicides; antiseptics; bovine protothecosis; disinfectants; genotype; molecular epidemiology